Collision with terrain

Executive summary

What happened

On 12 May 2023, an instructor and student pilot in a Magni M16C Tandem Trainer gyroplane, registered G1850, were conducting wheel balance exercises on runway 07 at Lake Macquarie Airport, New South Wales. Following the sixth of these exercises, the student made a radio broadcast while the instructor turned the gyroplane around and taxied on the runway toward the runway 07 threshold at the western end to repeat the exercise. Meanwhile, the pilot of an Extra EA 300L, registered VH-IOG, taxied from the apron for a scenic flight with one passenger. The Extra pilot made 2 radio broadcasts before entering the runway near the eastern end and taxied towards the runway 07 threshold. At about this time, the gyroplane commenced another exercise and accelerated down runway 07 towards the Extra. As the gyroplane approached the runway midpoint, the instructor and student observed the Extra about 20 m ahead. The instructor manoeuvred to avoid a collision, banking right before colliding with terrain resulting in substantial damage to the gyroplane. The instructor was seriously injured, with the student sustaining minor injuries. The Extra was not damaged, and its occupants were uninjured.

What the ATSB found

The ATSB found that neither aircraft’s pilots heard each other’s radio broadcasts and consequently, aircraft separation became reliant solely upon visual acquisition. The investigation found that the Extra pilot did not see the gyroplane before entering the runway, and subsequently taxied towards it. Also, while accelerating on the runway, the instructor and student in the gyroplane did not see the Extra taxiing towards them until a collision was imminent.

There were several factors that likely reduced the ability of the pilots to identify each other, including the small angular size of each aircraft, the complex background features with low relative contrast, and minimal relative movement between the aircraft.

Additionally, the tailwheel configuration of the Extra limited the pilot’s forward visibility and sun glare likely also affected the pilot’s ability to detect the gyroplane. The gyroplane pilots were likely also influenced by the higher workload associated with the training exercise which probably reduced their available attention for identifying conflicting aircraft.

What has been done as a result

The airport operator released a bulletin to all operators based at Lake Macquarie Airport highlighting the importance of a visual lookout in addition to radio discipline. A runway hold point line was repainted, and radio recording equipment will be purchased to allow radio communications to be periodically reviewed.

The operator of VH-IOG updated operational procedures to require a ground employee to have a hand-held radio switched on and in reach for all operations, and to monitor all departure and arrival radio calls. Pilots are now also required to stop at a hold point line before entering the runway for departure at Lake Macquarie Airport.

The Australian Sport and Rotorcraft Association (ASRA) advised the ATSB of its intent to replace the one-off human factors exam, completed as a requirement of the ASRA pilot certificate, with a recurrent exam, to be completed as part of each biennial flight review.

Safety message

The ATSB SafetyWatch highlights the broad safety concerns that come out of our investigation findings and from the occurrence data reported to us by industry. One of the safety concerns is reducing the collision risk around non-towered airports. This accident highlights the limitations of unalerted see-and-avoid in such an environment. Pilots are reminded of the importance of effective radio communications to increase traffic awareness and to ensure an effective visual scan to identify conflicting traffic.

The investigation

The occurrence

On the afternoon of 12 May 2023, an instructor and student pilot in a Magni M16C Tandem Trainer gyroplane, registered G1850 and operated by Airborne Flight Training, were planning to conduct wheel balance training exercises (see the section titled Operational information) at Lake Macquarie Airport, New South Wales. The airport was located within class G, non‑controlled airspace and had a designated common traffic advisory frequency (CTAF) on which pilots made positional broadcasts to coordinate aircraft separation.

At about 1537, the student and instructor pilots, seated in the front and rear seats respectively, taxied the gyroplane onto the runway near the runway 25[1] threshold and then backtracked[2] towards the runway 07 threshold (Figure 1) to commence the wheel balance training. The training exercise involved the student accelerating the gyroplane on the runway while balancing on the main landing gear until the gyroplane lifted off the ground briefly. The student then handed control to the instructor who would land on the runway, turn the gyroplane around and backtrack towards the 07 threshold before handing control back to the student and repeating the exercise.

At about 1542, the student pilot reported making a ‘rolling' radio call on the CTAF to indicate they were commencing the first wheel balance exercise. About 30 seconds later, after accelerating along the runway and briefly becoming airborne, the gyroplane landed about half-way down runway 07 and turned around. During this turn, the student reported making another radio call to indicate they were backtracking towards the runway 07 threshold.

At about 1543, the pilot of an Extra EA 300L, registered VH-IOG and operated by Inverted Downunder, walked towards the aircraft, which was located on the airport apron near the eastern end of the runway, to prepare for a scenic flight with one passenger. This was to be the pilot’s fifth flight of the day in the Extra.

Figure 1: Lake Macquarie Airport showing G1850 estimated ground track and VH-IOG location

G1850 track estimated using CCTV footage and pilot statements. VH-IOG location based on CCTV footage.

Source: Google Earth, annotated by ATSB

At about 1544, the gyroplane’s student pilot commenced a second wheel balance exercise from the runway 07 threshold. While the gyroplane was undertaking this exercise, airport video footage showed that the pilot of the Extra stepped onto the parked aircraft’s wing to prepare the front seat for the passenger. By about 1545, the gyroplane had travelled towards the end of runway 07, adjacent to the apron area and was slowing down to turn around (Figure 2). The student recalled that during the turn, a backtracking radio call was made. At about the same time, the video footage showed the Extra’s pilot, who was still on the wing, appear to look up for about a second toward the gyroplane. Shortly after, the passenger climbed into the front seat of the Extra, while the gyroplane backtracked towards the runway 07 threshold.

Over the next 8 minutes, the Extra’s pilot secured the passenger in their seat, provided a pre-flight briefing, and then climbed into the rear seat, putting their seatbelt and helmet on. During this time, the instructor and student pilot performed a further 4 wheel balance exercises, with the gyroplane turning around at different locations along the runway (Figure 2), but none as far as during the second wheel balance exercise (near the airport apron). The student pilot and instructor recalled radio calls being made prior to the commencement of, and during the turnaround at the end of, each wheel balance exercise.

Figure 2: G1850 turnaround locations

Source: Google Earth, annotated by ATSB

At 1554:05, a few seconds after turning around following the sixth wheel balance exercise, the Extra’s pilot started the aircraft’s engine and conducted pre-flight checks which included switching on the aircraft’s radios.

At 1554:39, the Extra’s pilot began to taxi towards the runway while the gyroplane was backtracking along runway 07. At about 1554:53, the Extra’s pilot reported making a radio call on the CTAF that the aircraft was taxiing for runway 07.

At about 1555:09, and for about the next 10 seconds while taxiing, the Extra pilot reported visually looking for aircraft on final approach for runways 25 and 07, and for aircraft on the runway. The pilot recalled that most of their attention during this visual lookout was towards the ‘bad lighting’ at the runway 07 threshold and they recalled not seeing any aircraft. During this time, the Extra pilot made another radio call advising they were entering and backtracking runway 07. Shortly after, the aircraft crossed the hold point line without stopping and turned left onto the runway (Figure 3). The pilot stated that they did not usually stop at this line because they had unobstructed views towards the runway 07 threshold and final approach to runway 25 before this point. At a similar time, the student commenced the seventh wheel balance exercise from the runway 07 threshold. Both gyroplane pilots recalled that they did not see any aircraft on the runway at this time, nor  could they recall making a ‘rolling’ radio call prior to this exercise.

As the Extra backtracked runway 07, the student was accelerating the gyroplane along the runway. About 30 seconds later, as the gyroplane approached the midpoint of the runway, the instructor and student observed the Extra about 20 m ahead and backtracking towards them. The instructor took control and banked the gyroplane right to avoid a collision. The rotor blades impacted the runway surface before the gyroplane veered off the runway and collided with terrain, coming to rest on its side. The gyroplane sustained substantial damage to the rotor blades, propeller blades, and landing gear. The instructor was seriously injured, with the student sustaining minor injuries. The Extra pilot saw the gyroplane veer off the runway to the left, stopped their aircraft and exited to provide assistance. The Extra was not damaged and its occupants were uninjured.

Figure 3: G1850 and VH-IOG ground tracks before accident

Labels ‘A’ and ‘B’ are timestamps for the approximate locations of each aircraft.

Source: Google Earth, annotated by ATSB

Context

Pilot information

G1850 pilots

The instructor pilot held an Australian Sport Rotorcraft Association (ASRA)[3] pilot certificate and was approved by ASRA as a chief flying instructor (CFI). They had accrued 2,254 hours of flying time in gyroplanes and about 751 hours on the Magni M16 and Magni M16C Tandem Trainer gyroplane, with 43 of those hours flown in the previous 90 days.

The student held an ASRA pilot certificate and a Private Pilot Licence (aeroplane). The student had accrued about 330 hours of flying time in aeroplanes, and 60 hours in gyroplanes, 10 of which were on the Magni M16C Tandem Trainer gyroplane in the previous 90 days.

VH-IOG

The Extra pilot held a Civil Aviation Safety Authority (CASA) Commercial Pilot Licence (Aeroplane). They had accrued 7,800 hours of flying time, with about 600 hours on the Extra EA 300L, of which 18.5 hours were flown within the previous 90 days.

Aircraft information

G1850

The Magni M16C Tandem Trainer is a 2-seat gyroplane with fixed tricycle landing gear (Figure 4). A 4‑cylinder piston engine drives a 3-bladed pusher propeller, with an unpowered rotor to develop lift. The gyroplane has a pre-rotation system linking the engine to the rotor which, when engaged, can drive the rotor to start it spinning without needing forward motion.

The Magni M16C is 4.7 m long, 2.7 m high (fuselage about 1.5 m high), and 1.8 m wide, with a rotor diameter of about 8.5 m. An external landing light was fitted to the front of the fuselage with strobe lights fitted to each side of the fuselage and one on the rear of the mast.

The front seat was instrumented for the pilot in command and was occupied by the student. The rear seat was not fitted with instrumentation but had flight controls, and was slightly higher than the front seat to improve forward visibility. Both seats were fitted with 4-point harnesses and both pilots were wearing them at the time of the accident.

Figure 4: G1850

Source: Airborne Flight Training

VH-IOG

The Extra EA 300L is a low-wing, 2-seat aerobatic monoplane with fixed tailwheel landing gear and the rear seat was instrumented for the pilot in command. A 6-cylinder piston engine drives a 3-bladed tractor propeller. VH-IOG was manufactured in Germany in 1999 and first registered in Australia in June 2005 (Figure 5).

The aircraft is about 7 m in length and 1.8 m high while on the ground with a wheel track of 1.8 m and a wingspan of 8 m. External navigation and strobe lights were fitted to the wingtips.

Figure 5: VH-IOG

Source: Inverted Downunder

Operational information

The gyroplane instructor planned for the student to perform several wheel balance exercises to teach the student the correct pitch attitude for take-off, and the exercise included many similar aspects of a normal take-off. The United States Federal Aviation Administration (FAA) Rotorcraft Flying Handbook[4] described a normal gyroplane take-off as follows:

The instructor stated that if the student obtained the correct pitch attitude, the gyro would lift‑off briefly, before the instructor would take control and land on the runway, turn around, backtrack towards the runway 07 threshold, and repeat.

The instructor also stated that during the acceleration phase of the wheel balance exercise, the workload was high due to the multi-tasking required in monitoring the gyroplane’s attitude, the student’s flight control inputs, and the gyroplane’s response.

The student stated that during the acceleration phase of each wheel balance exercise, they glanced down occasionally to look at the cockpit instrumentation, but their focus was primarily on looking out of the aircraft and monitoring the gyroplane’s pitch attitude.

Meteorological information

The weather at Lake Macquarie Airport at the time of the accident was good with a light easterly wind, visibility greater than 10 km, and no cloud over the airport.

At the time the Extra’s pilot was taxiing towards the runway from the apron (heading north), the sun was positioned at about the 10 o’clock (300°) position,[5] at an elevation of about 12°. This would have placed the sun in the pilot’s field of view while looking towards the runway 07 threshold (Figure 6). It is likely that the gyroplane would have been illuminated by the sun at this time. The Extra pilot stated that as there was a light wind, a take-off from runway 07 was preferable since the sun was getting low in the west making it difficult to look in that direction. The pilot stated that they were wearing a tinted helmet visor, which would have reduced sun glare.

Figure 6: VH-IOG turning left to backtrack runway 07

Source: Airport operator

While the gyroplane was accelerating towards the Extra on runway 07 during the seventh and final wheel balance exercise, the sun was positioned behind the gyroplane at about the 8 o’clock position. The Extra was likely illuminated by the sun while backtracking along the runway towards the gyroplane.

Airport information and procedures

Lake Macquarie Airport was an aircraft landing area,[6] located about 20 km southwest of Newcastle, New South Wales. It had an elevation of 5 ft above mean sea level, and a single, sealed 880 m long and 11 m wide runway designated 07/25, with trees lining each side.

As a non-controlled airport, separation between aircraft was maintained by ‘alerted see-and-avoid’ principles guided by Civil Aviation Safety Authority (CASA) advisory circulars[7]. Unalerted see‑and‑avoid relies on a pilot or crew visually detecting other aircraft without the assistance of other aids or information. This visual detection can be improved through pilots being alerted to an aircraft’s presence by radio, electronic systems, or other means (alerted see‑and-avoid).

At Lake Macquarie Airport, the carriage and use of a radio was required by the airport operator for all operating aircraft. Pilots were required to broadcast their position and intention so that nearby traffic would have an awareness of their aircraft and be able to plan or act accordingly.

All 3 pilots were familiar with the airport operations and had operated at Lake Macquarie for many years. Both aircraft were on the correct CTAF frequency before the accident, with all pilots having 2-way communications with other aircraft. None of the pilots reported hearing the other aircraft’s radio calls. The gyroplane pilots could not recall whether they had made a rolling call at the start of the final wheel balance exercise.

The Extra pilot reported that once they had taxied clear of the apron toward the hold point line, there was nothing obstructing their view of the runway 07 threshold other than the lighting conditions. The gyroplane instructor similarly reported no limitations with visibility of the entire runway when viewed from the runway 07 threshold.

The Extra pilot stated that there had been historically poor radio usage at the airport, and that they needed to use visual lookout ‘aggressively’ and not rely on radio communications. The gyroplane instructor considered radio to be a secondary means of collision avoidance to visual lookout.

Limitations of see-and-avoid

The see-and-avoid principle has been an effective defence in preventing aircraft collisions, but has several limitations (ATSB, 1991).

Workload

See-and-avoid can only be effective when the pilot is looking outside the cockpit. However, many tasks require pilots to direct their attention inside the aircraft, particularly when conducting operations and tasks that involve a high workload.

There was an opportunity for the Extra pilot to become aware of the gyroplane while they were on the Extra’s wing preparing the passenger’s seat, when they looked up briefly toward the gyroplane turning around on the runway. However, the Extra’s pilot recalled being unaware of any other operations being conducted at the airport while on the apron preparing the passenger for the flight. It is possible that the pilot’s focus on preparing the aircraft and passenger for flight resulted in them not detecting the gyroplane despite appearing to look towards it.

Although the Extra had occupied the runway for about 30 seconds before the gyroplane pilots saw the aircraft, the gyroplane pilots’ focus on other traffic in the runway environment was probably limited due to the complex training exercise being conducted. The instructor and student’s attention was primarily focused on the gyroplane’s motion and attitude to ensure the exercise was being conducted appropriately.

Visual search

In daylight, a pilot must look almost directly at an object to see it and it is possible for a pilot to look past an object if they do not see it directly. An FAA advisory circular recommended scanning the entire visual field outside the cockpit with eye movements of 10 degrees or less, with about a second spent on each 10 degree sector, to ensure effective detection of conflicting traffic.[8]  

It was estimated that the Extra pilot would have spent about 10 seconds on their visual lookout which included viewing both ends of the runway and associated approaches. While the Extra’s pilot was approaching the runway from the apron, the runway 07 environment would have been captured in a sector about 30 degrees horizontal by 10 degrees vertical. This suggests that the Extra pilot would have required at least 3 seconds for an effective visual scan of the runway (without accounting for any other factors). While the pilot probably spent at least that length of time viewing the runway 07 environment, there were other factors that likely affected their visual scan and their ability to detect the gyroplane in that time.

Cockpit visibility

Items such as window pillars, sun visors, and front seat occupants may impact on the pilot’s ability to see an aircraft. The FAA Airplane Flying Handbook[9] described the reduced forward visibility of tailwheel aircraft:

The pilot reported that the Extra EA 300L had limited visibility from inside the cockpit between 11‑1 o’clock directions while on the ground. Their usual procedure at Lake Macquarie Airport was to undertake a ‘zig-zag’ manoeuvre at the half-way point of the runway to allow them to see the runway environment and ensure the final approach was clear of traffic. The manoeuvre was only performed once as the narrow runway required the aircraft to slow down significantly. On this occasion, the accident occurred before the Extra had reached the half-way point on the runway.

Threshold for acuity

The eye’s ability to recognise an object also depends on the relative size of the object and an approaching aircraft might be too small to be seen. Studies have estimated the size an object needs to be for it to be sighted, with estimations of visual angle varying from about 0.02° to detect features of an alphabet letter (Howett, 1983), to at least 0.2° (NTSB, 1988) to reasonably detect an overall object. However, visual acuity varies widely across the retina of the eye and therefore, these values are only of relevance when looking directly at an object. Additionally, these observations were conducted under certain conditions, for example high object contrast with the background and moderate illumination (Howett, 1983), while the particular conditions experienced by the pilots involved in this occurrence were likely different.

With the Extra’s pilot at the hold point line and the gyroplane at the runway 07 threshold lined up with the runway, the estimated angular size of the gyroplane’s fuselage including landing gear would have been between 0.11° (height) and 0.14° (width). If the gyroplane pilots were at the runway 07 threshold and looked towards the runway 25 end with the Extra facing them on the runway, the estimated angular size of the Extra’s fuselage would have been about 0.14° (height and width). While the angular size of the Extra’s wingspan and the gyroplane’s rotor would be larger, these were both thin making them difficult to detect at such a distance compared to each aircraft’s fuselage.

Background features

Detecting an aircraft can become more difficult against a complex background that has different colours, contours, and objects. Aircraft are more easily spotted if they have a high contrast with their background. Images taken from around the midpoint on the runway about 20 minutes after the accident (Figure 7) provided some indication of the background features present at the time of the accident:

• The background behind the runway 07 threshold end had some small dark areas of shrub where the gyroplane’s white fuselage illuminated by the sun would have provided good contrast. However, the fuselage and background area covered by the shrub were small, and the light blue of the lake, and lighter terrain areas covered with haze in the distance, would have a presented a lower contrast difference with the white fuselage.
• Behind the runway 25 threshold was a highway at the same elevation as the runway, which video footage showed was busy with traffic around the time of the occurrence, with trees illuminated by the sun behind the highway. Although the Extra’s yellow nose and spinner would have been illuminated by the sun during the wheel balance exercise, the background behind the Extra had the sideways motion of traffic at the same level as the Extra creating a more complex scene. In addition, the trees in the background were also illuminated by the sun potentially reducing the contrast of the nose and spinner as the Extra moved closer to the gyroplane.

Figure 7: background features at runway ends

Source: Inverted Downunder

Other factors affecting visibility

In regard to aircraft lighting, research has shown that lights are generally ineffective in daylight at making an aircraft more visible, especially against bright sky backgrounds and can be less conspicuous than the aircraft itself, but may make aircraft more visible against terrain or in conditions of low light.  The Extra’s strobe lights were off while the aircraft was backtracking runway 07. The gyroplane strobe lights were on at the time of the accident and the landing light was off.

Glare occurs when unwanted light enters the eye. Glare can come directly from the light source or can take the form of veiling glare, reflected from crazing or dirt on the windscreen. The Extra’s pilot reported that the cockpit canopy was cleaned between flights and had some scratches as it was the original canopy fitted from manufacture. Although the pilot was wearing a sun visor to reduce glare, the sun would have been in the pilot’s field of view while looking towards the runway 07 threshold before entering the runway. The associated glare, which may have been exacerbated by the cockpit canopy, would have probably reduced the pilot’s ability to detect the gyroplane.

Additionally, it is difficult to see another aircraft when there is little relative motion between one aircraft and the other, such as when they are moving towards the same location in space. There was little relative movement between the 2 aircraft while (a) the gyroplane pilots were accelerating towards the backtracking Extra and (b) the gyroplane was positioned near the runway 07 threshold while the Extra pilot was visually looking towards that location before turning onto the runway.

Recorded data

Airport video footage from several locations captured the Extra pilot’s pre-flight activities, taxi, and backtrack towards the runway 07 threshold. The footage also showed segments of the gyroplane’s wheel balance exercises when in view from around the middle of the runway towards the runway 25 threshold. Footage of the runway 07 threshold up to the runway midpoint was not captured by any available video camera.

CTAF radio broadcasts were not recorded at Lake Macquarie Airport. Of the airports that operated on the same CTAF, Warnervale Airport (28 km south-west of Lake Macquarie Airport) was the only airport that recorded radio transmissions. Due to distance and line-of-sight limitations, radio calls on or near the ground at Lake Macquarie were not normally received at Warnervale Airport. The ATSB reviewed recorded radio calls from Warnervale while both the Extra and gyroplane were operating at Lake Macquarie Airport, however, no radio calls from either aircraft were recorded. No recorded data was available from either aircraft.

Safety analysis

Radio alerting

The gyroplane student pilot recalled making backtracking radio calls when turning around at the end of every wheel balancing exercise. However, the final backtracking call was made before the Extra pilot had turned the aircraft’s radio on, and therefore, they would not have heard this radio call. Additionally, the gyroplane pilots could not recall making a rolling call at the commencement of the final wheel balancing exercise prior to the accident, and there were no other sources of evidence to assist in establishing whether this call was made. In any event, the Extra pilot reported that they did not hear any call.

The Extra pilot reported making 2 radio calls before entering the runway. However, for reasons that could not be determined, the gyroplane pilots reported that they did not hear these calls. Consequently, neither aircraft’s pilots were alerted to the other’s presence over the radio and therefore, aircraft separation became solely reliant on each aircraft’s pilots seeing each other.

Visual search

The gyroplane was operating on the runway for about 11 minutes while the Extra pilot was on the apron preparing for the flight. During this time, the gyroplane was primarily on an area of the runway some distance from the pilot and not directly in sight, limiting the Extra pilot’s ability to detect it during this time.

The Extra pilot did not sight the gyroplane before entering the runway. The gyroplane pilots also did not sight the Extra at the start of their seventh and final wheel balance exercise, or while accelerating on the runway until a collision was imminent. While the reasons for this could not be determined, there were likely many common factors that reduced the ability of the pilots to identify each other such as the small angular size of each aircraft, the complex and cluttered background with reduced contrast difference, and the minimal relative movement between each aircraft.

The effectiveness of the Extra pilot’s visual scan was likely also affected by sun glare before entering the runway, and the tailwheel configuration of the aircraft which limited forward visibility while backtracking. The gyroplane pilots were likely also influenced by the higher workload associated with the training exercise, which probably reduced their available attention for identifying conflicting aircraft.

Findings

From the evidence available, the following findings are made with respect to the collision with terrain involving Magni M16C Tandem Trainer gyroplane, G1850, while avoiding Extra EA 300L, VH‑IOG.

Contributing factors

• Before entering the runway, the pilot of VH-IOG did not see G1850 occupying the runway and subsequently backtracked towards G1850. As VH-IOG was a tailwheel aircraft, the pilot was unable to sight G1850 while backtracking.
• While accelerating on the runway, the instructor and student in G1850 did not see VH-IOG backtracking towards them until a collision was imminent. While manoeuvring to avoid a collision, G1850 collided with terrain.

Safety actions

Safety action by Lake Macquarie Airport

In May 2023, the airport operator released a bulletin reminding all operators based at Lake Macquarie Airport of several aspects of safe operational practice highlighted by this event, including that:

• aircraft should stop forward motion at the hold point line (or equivalent for helicopters) to ensure a good lookout prior to entering the runway environment
• pilots are to ensure they know and use correct radio terminology while operating at the airport and to broadcast their intentions
• although radio discipline was required, it cannot be relied upon for safety, and that the visual lookout was paramount
• for operations involving a backtrack for runway 07, aircraft should turn through 90° in the turning node at the far end, stop to lookout, then broadcast a radio call on lining up
• the runway should only be occupied for the minimum time required to either taxi, take off, or land.

The airport operator also advised that:

• the hold point line at the apron end of the runway (near the runway 25 threshold) had been repainted and a hold line also painted at the runway 07 end
• CTAF radio recording equipment was purchased and anticipated to be installed in February 2024. This will ensure all communications can be reviewed periodically, and in the event of an incident.

Safety action by Inverted Downunder

The operator of VH-IOG advised the ATSB that operational procedures were updated to include requirements for:

• a ground employee to have a hand-held radio, switched on and in reach for all operations, and to monitor any departure and arrival radio calls
• pilots to stop at the hold point before entering the runway for departures.

Safety action by Australian Sport Rotorcraft Association

The Australian Sport Rotorcraft Association (ASRA) advised the ATSB that, in response to this accident and other previous sport rotorcraft accidents, ASRA intends to replace the one-off human factors exam, which is completed as a requirement of the ASRA pilot certificate, with an updated exam to be completed recurrently as part of each biennial flight review.

Sources and submissions

Sources of information

The sources of information during the investigation included the:

• pilot and passenger of the VH-IOG
• instructor and student of G1850
• VH-IOG operator photos
• New South Wales Police Force photos
• CCTV footage from Lake Macquarie Airport and Westpac Rescue Helicopter Service

References

Australian Transport Safety Bureau (1991), Limitations of the See-and-Avoid Principle.

CASA (Civil Aviation Safety Authority (2021), Operations in the vicinity of non-controlled aerodromes, AC 91-10v1.1.

CASA (Civil Aviation Safety Authority (2021), Pilots' responsibility for collision avoidance, AC 91‑14v1.0.

FAA (Federal Aviation Administration) (2021), Airplane Flying Handbook, FAA-H-8083-3C, United States.

FAA (Federal Aviation Administration) (2000), Rotorcraft Flying Handbook, FAA-H-8083-21, United States.

FAA (Federal Aviation Administration) (2022), Pilots’ Role in Collision Avoidance, Advisory Circular 90-48E, United States.

Howett, G. L. (1983), Size of letters required for visibility as a function of viewing distance and observer visual acuity (National Bureau of Standards Technical Note 1180).

National Transport Safety Board (1988), Aircraft Accident Report - Midair Collision of Skywest airlines Swearingen Metro II, N163SW, and Mooney M20, N6485U, Kearns, Utah, January 15, 1987.

Submissions

Under section 26 of the Transport Safety Investigation Act 2003, the ATSB may provide a draft report, on a confidential basis, to any person whom the ATSB considers appropriate. That section allows a person receiving a draft report to make submissions to the ATSB about the draft report.

A draft of this report was provided to the following directly involved parties:

• Pilot of VH-IOG
• instructor and student of G1850
• operators of VH-IOG and G1850
• Lake Macquarie Airport
• the Australian Sport Rotorcraft Association (ASRA)
• the Civil Aviation Safety Authority (CASA).

Submissions were received from:

• instructor and student of G1850
• operator of G1850.

The submissions were reviewed and, where considered appropriate, the text of the report was amended accordingly.

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Executive summary

What happened

On 4 April 2023, the pilot of a Robinson R44 Raven II helicopter, registered VH-WLH, was conducting aerial mustering operations on at Bingegang, Queensland (about 60 km south-east of Middlemount). The pilot was the only person on board.

While the pilot was reportedly flying to look for straggling cattle the helicopter struck an aerial powerline and collided with terrain. The pilot was fatally injured and the helicopter was destroyed by post-impact fuel-fed fire.

What the ATSB found

The pilot had an operational reason to be in the area at low level at the time of the accident. There was no evidence of pre-existing helicopter defects and the terrain was generally suitable for a landing had an in-flight emergency arisen.

The pilot was reportedly familiar with the property and knew that there was a powerline running across it, although it was not possible to conclusively determine the level of awareness they had of the wire’s presence and location during the flight. The ATSB concluded that the pilot likely lost awareness of, and did not see, the unmarked aerial powerline during low-level aerial mustering.

The powerline was not marked and nor was there a requirement to do so. The helicopter model was not able to be fitted with wirestrike protection equipment.

Safety message

This accident provides another reminder of the dangers posed by aerial powerlines during low-level mustering. There are limits to the extent to which operators can mitigate the risk of wirestrike during low-level operations near powerlines. Helicopter wirestrike protection (WSPS) can provide a last line of defence in the event of a wirestrike. Some aircraft selected for aerial agriculture operations can be configured to include WSPS. However, this technology is not currently available on smaller helicopters such as the Robinson R44.

The ATSB has released, in association with the Aerial Application Association of Australia (AAAA), an educational booklet, Wirestrikes involving known wires: A manageable aerial agriculture hazard (AR-2011-028). This booklet contains numerous wirestrike accidents and lessons learned from them.

Electrical power and telecommunications companies in Australia can mark powerlines that are identified as a hazard for low-level flying operations and some have a safety scheme to reduce the costs to property owners.

The investigation

The occurrence

On 4 April 2023, the pilot of a Robinson R44 Raven II helicopter, registered VH-WLH, was conducting cattle mustering operations on a private property at Bingegang, Queensland (about 60 km south-east of Middlemount), owned and operated by the pilot’s family business. The pilot was the only person on board and was reported to be familiar with the property. The weather was clear.

Mustering commenced early in the morning and according to witnesses the pilot took a 60–90 minute break before recommencing at about 1000. At about 1110, after mustering a large mob of cattle into a holding paddock, the pilot flew back to one corner of the lot to look for stragglers. The pilot then radioed for workers on the ground to help with further mustering.

As the workers approached, they saw a plume of smoke and were unable to contact the pilot via radio. They then saw that the helicopter had struck a single-strand aerial powerline and collided with terrain. The wreckage was on fire. The pilot was unresponsive and the workers were unable to remove the pilot due to the increasing intensity of the fire.

The pilot had been fatally injured and the helicopter was destroyed by post-impact fire.

Context

Personnel information

The pilot held a private pilot licence with a class rating for single-engine helicopters and a helicopter low-level operational rating. The pilot held a class 2 civil aviation medical certificate which included the requirement for distance vision correction lenses to be worn and reading correction lenses to be available. It was reported that the pilot always wore glasses, was wearing them on the day of the accident, and that they knew of the presence of the powerline on the property.

Aircraft information

The helicopter was a Robinson R44 Raven II, serial number 14253, manufactured in the United States in 2018 and registered in Australia on 30 October 2018. It was issued with a certificate of airworthiness in the normal category on 16 November 2018.

The R44 is a single-engine, light utility and training helicopter with a semi-rigid, two-bladed main rotor, a two-bladed tail rotor and skid type landing gear. It has an enclosed cabin with two rows of side-by-side seating for a pilot and three passengers. The pilot sat on the right side, and extensive windows at the front of the helicopter afforded generally excellent visibility ahead. The accident helicopter was being flown with the doors fitted.

A wirestrike protection system (WSPS) was not fitted to the accident helicopter. In general, smaller helicopters such as Robinson R22 and R44 series had no structural hard points to fit a wirestrike protection system, were too light, and in many instances travel too slowly for a WSPS to be effective.[1]

Site information

Figure 1 shows an overview of the accident site. The powerline, a single-wire earth return (SWER) wire that ran across the property, was not marked and there was no requirement within the applicable aviation regulations, Australian Standards or elsewhere to do so. The wire was estimated to be at a height of 5.6 m at the point of impact.

The terrain was clear to the right of the helicopter’s flightpath, and there were trees taller than the wire height that would have obscured the wire and pole on the left side.

Figure 1: Accident site

Source: Google, Queensland Police. Annotated by the ATSB

The helicopter impacted terrain left side down and yawing to the right about 90 m beyond the point of contact with the wire and facing back towards the wire. There was insufficient evidence available to determine the angle and speed of impact with the ground.

Visibility of powerline

Queensland Police officers later returned to the accident site to conduct a simulation using a remotely piloted aircraft system (RPAS) of the helicopter’s approximate flight path and height prior to striking the powerline assuming that it had not turned. The simulation was conducted in conditions similar to those on the day of the accident. Images from the RPAS simulating what the pilot would have seen when approaching the wire showed the wire was difficult to distinguish from the background and the left pole was obscured by trees (Figure 2).

Figure 2: RPAS simulation of flight path

Source: Queensland Police, annotated by the ATSB

Wreckage information

The ATSB examined the aircraft wreckage after it was moved to a secure facility by Queensland Police.

The examination of the wreckage indicated that the impact with terrain was likely not survivable. The helicopter’s cockpit, systems and engine were severely damaged by the impact and post-impact fire. Within the limitations of the available evidence, there were no indications of pre-flight defects, in-flight fire or birdstrike.

The examination found that the wire was struck between the helicopter’s nose and the upper surface of the skids. Additionally, the wire marks on the upper surface of both skids were similar, and in conjuction with the position of the wreckage indicated the helicopter was travelling about perpendicular to the wire.

During the accident sequence, the rotor struck and separated the tail boom. The nature of this damage, and other evidence, indicated that the rotor had high energy at the time.

Marks on the left oil cooler indicated that the engine and ring gear were rotating at the time of impact. Other impact marks indicated that the engine stopped rotating during the impact sequence.

The helicopter’s warning light filaments, including a carbon monoxide warning, were consistent with them not being illuminated at impact.

The helicopter was fitted with a bladder fuel tank, which was breached during the accident sequence. Due to the intense fire, it was not possible to assess how the tank was breached.

Maintenance information

The helicopter’s most recent periodic (100-hourly) inspection was carried out on 6 September 2022, at 660.6 hours in service, after which a maintenance release was issued. A review of all previous maintenance releases identified no discrepancies or significant defects. The most recent maintenance (a tail rotor blade inspection) was carried out at 674.1 hours, on 6 January 2023.

At each periodic maintenance inspection, engine cylinder compression checks were carried out. The tests resulted in satisfactory compression. However, during the most recent test (at 660.6 hours in service), the variation in compression levels was at the lower limit (10–15 psi) of where a re-test should be made within 10 engine operating hours (no later than 670.6 hours in service). There was no record that this was carried out, however, the time in service at the time of the accident could not be determined as the maintenance release was not found and was likely destroyed in the post-impact fire.

Medical and pathological information

A toxicological examination showed the pilot did not have elevated levels of carbon monoxide at the time of the accident and tests for other substances likely to have an effect on performance were negative.

Witnesses reported that the pilot was wearing the helicopter’s three-point harness. The pilot was not wearing a helmet.

A final post-mortem examination report was not available at the time of publication, however, the autopsy certificate for the pilot recorded the cause of death as chest injuries resulting from the accident.

Safety analysis

Sources and submissions

A submission was received from the operator. The submission was reviewed and, where considered appropriate, the text of the report was amended accordingly.

Purpose of safety investigations The objective of a safety investigation is to enhance transport safety. This is done through: identifying safety issues and facilitating safety action to address those issues providing information about occurrences and their associated safety factors to facilitate learning within the transport industry. It is not a function of the ATSB to apportion blame or provide a means for determining liability. At the same time, an investigation report must include factual material of sufficient weight to support the analysis and findings. At all times the ATSB endeavours to balance the use of material that could imply adverse comment with the need to properly explain what happened, and why, in a fair and unbiased manner. The ATSB does not investigate for the purpose of taking administrative, regulatory or criminal action. Terminology An explanation of terminology used in ATSB investigation reports is available here. This includes terms such as occurrence, contributing factor, other factor that increased risk, and safety issue. Publishing information  Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2023 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

Executive summary

What happened

On 17 March 2023, the pilot of a Cirrus SR22, registered VH-XGR, was conducting a private flight under the instrument flight rules from Southport, Queensland to Bankstown, New South Wales. 

During the landing, the aircraft sunk onto the runway and bounced along the runway for about 5 seconds, then rapidly entered a steep climbing turn to the left. Having reached a maximum height of about 40 ft, the bank angle exceeded 90° and the aircraft dropped onto the left wing and nose. 

When emergency services arrived at the site, the aircraft was upside down on the grass between the runways. The left wing had detached, and fuel was leaking from the right side. The pilot was strapped in and conscious but confined in the aircraft. 

Once the site had been blanketed with fire suppression foam and the aircraft stabilised with step blocks, ambulance personnel were able to attend to the pilot. Rescue personnel stabilised the wreckage and used a reciprocating saw to cut the left side of the inverted fuselage to extricate the pilot. 

When the pilot was extricated, their condition suddenly deteriorated they were taken to hospital in a critical condition and later died from injuries sustained in the accident.        

During the rescue process the site commander was advised that the aircraft was equipped with a ballistic parachute. A Cirrus-qualified maintenance engineer then attended to render the ballistic system safe from inadvertent activation. 

What the ATSB found

In the early stages of a go-around from an unstable landing, the pilot was unable to counter the substantial torque effect associated with high engine power, low airspeed, and high pitch angle, resulting in loss of control and collision with terrain.

The emergency responders were initially unaware that the aircraft was equipped with a ballistic parachute (CAPS) and initiated the recovery of the pilot with the system still armed. By not securing the CAPS, the risk of inadvertent rocket activation and injury was increased.    

Cirrus Aircraft provided training, education, and placards to reduce the risk of inadvertent post‑accident actuation of the ballistic parachute (CAPS) rocket and associated injury. However, the training and education had limited reach, and the placards did not clearly communicate the danger or provide access to safety information.

The ATSB also identified an opportunity for Cirrus to enhance the safety benefit of their go-around related training and educational products, especially in regard to the SR22 models that were equipped with relatively high-power engines.

What has been done as a result

Cirrus Aircraft advised that they had enhanced the external CAPS placarding on 2 new models of aircraft (the SF50, and another in development) to align with current American Society for Testing and Materials (ASTM) standards. The SR2X series of aircraft (the SR20, SR22, and SR22T) were certified prior to the implementation of ASTM standards. At the time of writing, Cirrus was reviewing the possibility of enhancing the placard that was certified with SR2X. 

During the draft report review process the ATSB sought input from Cirrus as to whether there was an opportunity to enhance the safety benefit of their go‑around training and educational products, especially in regard to the SR22 models that are equipped with relatively high-power engines during the landing phase.

Cirrus did not advise of any associated safety action.

Safety message

A go-around to recover from an unstable landing is more dynamic and presents a greater challenge than a go-around on approach. Although the procedure for go-arounds generally applies to both scenarios, it requires careful application when implemented in the landing phase.      

Pilots of single-engine aircraft with relatively high-power engines, such as the Cirrus SR22, need to be aware of the potential for significant torque effect and loss of control associated with high engine power, low airspeed, and high pitch attitude. 

The Cirrus Airframe Parachute System (CAPS) is credited with saving a number of lives but also presents a serious post-accident hazard when it has not been deployed and the aircraft is damaged. If the rocket is inadvertently activated, anyone in its path would be seriously or fatally injured. Cirrus Aircraft advises first responders that it is imperative that the presence of an airframe parachute system be identified as early as possible, and the system disabled to make it safer to work around.

The ATSB directs first responders/emergency services and airport operators to the Advisory Guide For First Responders: Cirrus First Responders (cirrusaircraft.com) to provide awareness and reduce the risk of inadvertent post-accident activation of CAPS and to the ATSB webpage ‘Hazards at aviation accident sites’. 

Additional safety information is available from the news item ‘Approach aviation accident sites with caution’ released in conjunction with the final report of ATSB investigation report AO-2018-038 and Flight Safety Australia article ‘Beware of the rocket in the wreckage’ published on 7 June 2019.

The investigation

The occurrence

On 17 March 2023, the pilot of a Cirrus SR22, registered VH-XGR, was conducting a private flight under the instrument flight rules[1] from Southport, Queensland to Bankstown, New South Wales. 

The aircraft departed Southport at 1211 Eastern Standard Time[2] and tracked initially to the south‑west. After a couple of minutes, the pilot turned the aircraft onto a southerly heading for the relatively direct track to Bankstown. The pilot initially climbed the aircraft to FL 180[3] for a couple of minutes then descended to FL 160 for the remainder of the cruise phase of the flight. All of the flight parameters—track, altitude and groundspeed—indicated normal operation.  

At 1504 Eastern Daylight-saving Time,[4] the pilot commenced descent and altered track slightly. There were other minor track changes, consistent with air traffic control (ATC) or airspace requirements, as the flight progressed towards visual flight rules (VFR)[5] reporting point Prospect Reservoir (Figure 1).[6]  

Figure 1: Sydney VTC extract showing Prospect Reservoir in top left corner and Bankstown Aerodrome in lower middle of image 

Source: Sydney VTC 

At 1533, the aircraft was over Prospect Reservoir on descent through 1,900 ft and tracking towards Bankstown Airport (Figure 2). Shortly after, the pilot transmitted on the applicable Bankstown Tower frequency: 

Bankstown Tower, Cirrus xray golf romeo (XGR), Prospect, 1,800, inbound with information November, and visual. 

In response, the aerodrome controller (ADC) instructed XGR to: 

Join final runway 11 Left[7] and report established at 3 miles. VFR traffic about 2 miles is a Tecnam. If you get a bit too close you can expect runway centre. 

This was acknowledged by the pilot of XGR. 

About 20 seconds later, the ADC advised XGR: 

I’ll make that a plan now, join final for runway 11 Centre. Report established 3 miles. Traffic is that Tecnam ahead. 

This was acknowledged by the pilot of XGR.

The ADC passed traffic information to the Tecnam with advice that the Cirrus would be overtaking to the right and to shift slightly to the left. This was followed by some traffic guidance to the pilot of XGR:

XGR suggest a slight right turn, the Tecnam is in about your one o’clock at 1 mile.

This was associated with a diversion of track slightly to the right for a minute and 15 seconds.   

The pilot then turned left to align the aircraft for final approach to runway 11C. At this point (1535:19), the aircraft was 2.87 NM (5.3 km) from the runway threshold, slowing down through 106 kt groundspeed, and about to descend from 950 ft.

As XGR was being turned onto finals, the ADC advised:

XGR runway centre number 1. Additional traffic is a Diamond late right downwind in the training circuit [runway 11 Right]. 

This was acknowledged by the pilot of XGR.

At 1535:45, the ADC advised: 

XGR runway centre cleared to land

This was promptly read back by the pilot of XGR:

Cleared to land on centre, XGR

That was the last communication with the pilot of XGR. At that point, XGR was 1.9 NM (3.5 km) from the threshold, on descent through 725 ft, and slowing down through 90 kt groundspeed. 

As the approach continued, the groundspeed continued to slow until reaching a groundspeed of 60 kt while on descent through 350 ft. The groundspeed varied between 60 and 63 kts until the last data point recorded at 100 ft. 

Figure 2: Track from Prospect reservoir to Bankstown Airport 

Source: Google Earth, annotated by the ATSB

Although some witnesses noted the speed of the Cirrus was relatively slow, there were no reports of anything abnormal until the landing. The landing was observed by pilots on concurrent approaches to the adjacent runways, and the aerodrome controller. A security camera recorded imagery of the accident sequence.      

The instructor in the right seat of the Tecnam (at about 200 ft on final for runway 11 Left) observed the Cirrus touchdown on the runway and bounce into the air to a height of about 10–20 ft. They advised that the aircraft appeared to be very slow, and it bounced again with low energy, with white dust evident from the tail area. It then started to veer to the right, pitched up violently and started to bank steeply to the left (towards runway 11 Left). Concerned about separation, the instructor initiated a go-around. The Cirrus came down on one wing and tumbled onto the roof, stopping quickly.

The instructor in the right seat of the Diamond (on short final for runway 11 Right) observed the Cirrus over the runway in a very high nose attitude and veering right. They advised that it then rolled sharply to the left, dropped the nose, and tracked over the grass between runways 11 Centre and 11 Left. The left wing impacted the ground first, followed by the nose, then flipped over onto the canopy.     

The ADC was observing the Cirrus as it was about to touch down. They advised that they saw the aircraft pitch up and reach about 30–40 ft then roll to the left. As the aircraft was crossing over towards runway 11 Left, the ADC issued a safety alert to the Tecnam (1537:38). It appeared to the ADC that the aircraft was accelerating as the left-wing tip impacted the ground followed by the nose.    

A camera mounted on the Bankstown Airport passenger terminal[8] recorded low resolution imagery of the accident sequence (Figure 3). It showed the aircraft sinking onto the runway, proceeding along the runway for about 5 seconds, then rapidly entering a steep climbing turn to the left. Having turned through 90° and reached a maximum height of about 40 ft, the bank angle exceeded 90° and the aircraft dropped onto the left wing and nose. This was also recorded by a camera in a different location.

Figure 3: Bankstown Airport terminal CCTV showing sequence from initial touchdown to just before impact (right to left)

Source: Bankstown Airport edited and annotated by the ATSB 

Bankstown Tower activated the aerodrome emergency plan, including notification to emergency services and the aerodrome reporting officer. The airport was subsequently closed, and traffic was processed out of the control zone. 

New South Wales (NSW) Police Force personnel arrived within 5–8 minutes of the notification, followed by NSW Ambulance. Fire and Rescue NSW (FRNSW) crews arrived about 8.5 minutes from receiving the call. Bankstown Fire Station crews usually responded to incidents at the airport, but they were unavailable so crews from Revesby Fire Station attended.           

When emergency services arrived at the site, the aircraft was upside down on the grass between the runways. The left wing had separated, and fuel was leaking from the right side. The pilot was strapped in and conscious but confined in the aircraft. 

The responding FRNSW crews did not include technical rescue personnel, so the site commander arranged for that expertise to attend. Once the site had been blanketed with foam and the aircraft stabilised with step blocks, ambulance personnel were able to attend to the pilot. 

Before starting the rescue, the crew strapped the rear fuselage to the ground. They then used a reciprocating saw to cut the left side of the inverted fuselage to extricate the pilot. The FRNSW personnel were unaware of any aircraft type-specific hazards and did not notice any no-cut labels on the aircraft.      

When the pilot was extricated, their condition suddenly deteriorated, and they were taken to hospital in a critical condition.        

About 15 minutes into the rescue process, the FRNSW site commander was advised that the aircraft was equipped with a ballistic parachute. The commander had a general awareness that a ballistic parachute was installed in the tail but found it difficult to get information about its operation. The airport owner arranged for a Cirrus-qualified maintenance engineer to render the ballistic parachute system, known as the Cirrus Airframe Parachute System (CAPS), safe from inadvertent activation.       

The maintenance engineer advised that they inserted a pin into the CAPS activation handle located in the cabin ceiling and taped it into place. They inspected the activation mechanism in the rear cargo compartment and found that the activation cable was not under tension and the rocket igniter switch firing pin had not moved. The electrical wires were not disconnected because of concern about the fuel spillage. On the day after the accident, the engineer disconnected a battery in the tail but, due to aircraft damage, was unable to access an additional battery in the front of the aircraft.      

Another Cirrus-qualified maintenance engineer who attended the aircraft the day after the accident advised that there was tension on the activation cable, and it was only marginally lower than the force required to move the pin. To render the CAPS safe for recovery of the wreckage, the engineer cut the activation cable and disconnected the electrical leads from the igniter switch.          

The pilot died in hospital on 6 April 2023 from injuries sustained in the accident.         

Context

Pilot information

The pilot held a private pilot licence (aeroplane), issued in 2011, with a single engine aeroplane rating. In addition, the pilot held a single engine aeroplane instrument rating and Night VFR rating. 

In February 2023, the pilot had recorded total flying experience of 860 hours, including 47 hours in the previous 6 months. Almost all of the total experience and all of the recent experience was reported to be operating VH-XGR.

The last training or check completed by the pilot was an instrument proficiency check (IPC) in VH‑XGR. This was attempted on 8 February 2023 but was not successful. The flight examiner advised that during a hand-flown instrument approach the pilot had allowed the aircraft to descend below the glidepath indication and develop a high rate of descent.   

As recommended by the flight examiner, the pilot then conducted some VFR flying (without an instructor) and a pre-IPC practice flight with the flight examiner. On 2 March 2023, the pilot attempted the IPC again with the flight examiner and was successful. 

The flight examiner recalled that over the course of the 2 recent IPCs, and associated practice flights, the pilot’s general flying, including circuits and landings, was unproblematic. Although those flights included a number of go-arounds that were safely executed, the flight examiner had discussed with the pilot the need to be cautious when applying power during go-arounds to ensure the aircraft remained easy to control.  

The flight examiner had completed the Cirrus Standardised Instructor Pilot training in 2020 and been involved in the pilot’s flying training and assessment during the previous 3 years. 

The pilot’s last aviation medical examination, conducted on 28 February 2023, was for a Class 2 medical certificate. This was revalidated by the designated aviation medical examiner with continuation of the restrictions that distance vision correction must be worn and reading correction to be available while flying.    

At the time of drafting the report, the postmortem report was not available. However, analysis of the radio transmissions made by the pilot to Bankstown Tower showed that these transmissions were appropriate and there were no indications of any abnormalities—­slowed/slurred speech patterns or simple errors—which could indicate a medical issue.  

Environmental conditions

The aerodrome forecast for Bankstown Airport issued at 1534 local time anticipated that between 1500 and 1700 the wind would be from 130 degrees (True) at 17 kt, visibility would be greater than 10 km with no cloud, temperature over the same time period was forecast to be 28°. At 1530, the wind was reported from 090 degrees (True) at 16 kts and the other conditions were consistent with the forecast.     

Wind speed and direction were recorded at Bankstown airport every minute. Those observations in the 2 minutes before and after the accident are presented in Table 1.   

Table 1: One-minute wind observations at Bankstown Airport on 17 March 2023 

*The closest observation to the time of the accident was at 1538. At that time, the angle between runway 11 (111° magnetic) and the recorded wind from the left (086° magnetic) was 25°. That provided a crosswind component of 6 kt from the left and headwind component of 13 kt. There was no significant variation in the minute before or after that time. 

Operational information for Bankstown Airport in the En Route Supplement Australia (ERSA) cautioned that:

During winds with a southerly direction, building induced mechanical turbulence may be experienced on final for RWY 11C and RWY 11R/29L. 

Although the prevailing wind was not from a southerly direction, the ATSB considered the potential for mechanical turbulence. The closest buildings in line with the direction of the wind were no higher than 3 levels and located at least 900 m from the threshold of runway 11 Centre. Given the wind strength and the distance of the buildings, it is unlikely that the buildings had any significant effect on the conditions for landing on runway 11 Centre.        

The instructor in the Tecnam advised that on approach and landing to runway 11 Left there was no significant crosswind or mechanical turbulence, and the conditions were relatively smooth. In addition, the ADC did not notice any disturbance to the flight path of aircraft on approach. 

Operating procedures

The Cirrus SR22 Pilot’s Operating Handbook included a procedure for balked landing/go-around: 

1. Autopilot .....................................................................DISENGAGE

2. Power Lever ........................................................FULL FORWARD

3. Flaps ........................................................................................50%

4. Airspeed........................................................................75-80 KIAS

After clear of obstacles:

5. Flaps .........................................................................................UP

Amplification 

In a balked landing (go around) climb, disengage autopilot, apply full power, then reduce the flap setting to 50%. If obstacles must be cleared during the go around, climb at 80-85 KIAS with 50% flaps. After clearing any obstacles, retract the flaps and accelerate to the normal flaps up climb speed.

Pilot training and operational guidance

Pilot training and assessment

Pilot training and assessing in Australia was carried out in accordance with the CASR Part 61 manual of standards (MOS). The competency standards for the Land Aeroplane unit included elements and performance criteria for conduct of a missed approach and recovery from a missed landing.

For both sequences, the criteria was to make a smooth positively-controlled transition from approach or missed landing to a missed approach including selection of power, attitude and configuration to safely control the aeroplane. The causes of loss of control during landing and contents of the pilot’s operating handbook were part of the underpinning knowledge requirements.  

The competency standards for night VFR and instrument approaches included the conduct of missed approaches.  

To safely exercise the privileges of a rating, a pilot must have completed a flight review for the rating within the previous 2 years. Once the pilot demonstrated competency in accordance with the Part 61 MOS, the instructor was able to assess it as completed. 

An instrument proficiency check (IPC) is an assessment of the pilot’s competency to conduct a flight in actual or simulated instrument meteorological conditions under the IFR to the standards specified in the Part 61 MOS. An IPC included missed approaches in the context of instrument approaches and was valid for 12 months.

Cirrus training and guidance material

Cirrus Aircraft provided an instructor pilot course intended to prepare qualified instructors with SR20/22 experience to provide high-quality standardised training to owner-pilots and students using Cirrus Aircraft-approved resources. The course included the demonstration, teaching, and assessment of landings and go-arounds with an emphasis on flight operations manual (FOM) procedures and use of the TOGA button, and memory items.   

Online training and education for pilots was also available through the Cirrus Approach portal. This included the FOM for the SR series aircraft that addressed standard operating procedures applicable to the traffic pattern, stabilised approaches, landings, and go-arounds. 

One of the specialty courses was ‘SR series Take-offs and Landings’ and 2 of the shorter presentations hosted on YouTube (Flight Fix) addressed go-arounds and stable approaches. 

The following information, selected for relevance to the occurrence, has been adapted from the FOM and online training/education resources.  

It was recommended that the autopilot was disconnected prior to entering the traffic pattern (circuit) and the yaw damper was off prior to landing.

For final approach, the target indicated airspeed (IAS) was 80 kt with full flap and engine power as required. One of the common errors on approach was not compensating for ballooning when deploying the flaps, resulting in excessive loss of airspeed and/or altitude gain.

A stabilised approach was defined as constant angle and constant rate of descent approach profile ending near the touchdown point. If this was not achieved, a go-around must be carried out. In addition, a go-around was recommended in situations such as excessive ballooning during landing or excessive bouncing.

A go-around was presented as a 4-part flow comprising:

1. Power Up – immediately but smoothly apply full power (as for take-off – typically 4–5 seconds), connected right rudder due to significant left turning tendencies (possible strong pitch up), and simultaneously;
2. Pitch Up – smoothly and initially to level attitude and begin accelerating. If the aircraft has a TOGA button and it is pushed, it provides pitch guidance on the primary flight display (PFD)
3. Clean Up – retract flaps to 50% then as the aircraft speed increases gently transition to V_x [speed for best angle of climb] or V_y [speed for best rate of climb]. When positive rate of climb and obstacles are cleared above flap retract speed of 80 KIAS, retract flaps to zero
4. Call Up – communicate as required.

Common errors included not maintaining coordination during the go-around, and improper pitch control resulting in excessive loss of altitude, stall entry, or both. This could occur if the aircraft was climbed out of ground effect before a safe airspeed was reached.      

Landing technique including in a crosswind was conventional. Common errors included the pilot flaring too high and creating a stall to hard landing situation. 

Rejected landing and go-around aerodynamics        

Engine power changes can affect stability. An increase of power may tend to make the nose rise (low thrust line tends to add to nose-up effect of horizontal tail surface). This effect can be exacerbated with full flap. 

In a single-engine propeller-driven aircraft, application of engine power will produce ‘torque’ in the form of a twisting or rotating motion around at least one of the 3 axes. For an aircraft with a clockwise rotating propeller (viewed from the cabin) such as the Cirrus SR22, the overall result will be a left turning tendency. This is the combined effect of 4 elements, which are briefly explained in the context of a clockwise rotating propeller.    

Torque reaction: as described by Newton’s Third Law of Physics, the revolution of the engine and propeller in one direction produces an equal force trying to rotate the aircraft in the opposite direction. As this induces a roll to the left when the aircraft is airborne, the design will generally compensate for this tendency in cruise (for example, by an offset engine and by provision of aileron trim). During the take-off roll, the increased loading on the left main wheel produces relatively higher drag and a turning moment to the left. The magnitude of the left roll and turn tendency is dependent on:

• size and power of the engine
• size of propeller and RPM
• size of the aircraft
• condition of the ground surface.         

Corkscrew effect: At high propeller RPM and low forward speed, the spiral or corkscrew rotation of the slipstream exerts a sideways force on the vertical fin, which produces a yawing moment to the left. In addition, the corkscrew flow of the slipstream produces a rolling moment to the right around the longitudinal axis. Although these forces may be counteracting each other, they vary greatly and require the pilot to apply the necessary corrective action.      

Gyroscopic action: as a spinning rotor, the propeller is subject to gyroscopic precession when a force is applied to the rim of the plane of rotation. In simple terms, any yawing about the vertical axis results in a pitching moment and any pitching around the lateral axis results in a yawing moment.     

Asymmetric loading (P-factor): when an aircraft is flying with a high angle of attack, the effectiveness of the downward moving blade is greater than that of the upward moving blade. This moves the centre of thrust to the right, which results in a yawing moment towards the left around the vertical axis. 

Aircraft information

General information

The aircraft was manufactured in 2009 by Cirrus Design Corporation in the United States to a GTS equipment specification and with G3 model features such as a redesigned carbon fibre wing. It was registered in Australia as VH-XGR in the same year.  

Although produced as an SR22, which was certified with a normally aspirated Continental Motors Inc. IO-550-N engine, the aircraft engine had been modified during manufacture in accordance with a supplementary type certificate. This involved installation of a Tornado Alley Turbo Inc. Turbonormalizing System that was designed to maintain sea-level performance of 310 hp up to the maximum altitude of 25,000 ft. As such, it was referred to as an SR22TN.    

One of the features of the aircraft was a single-lever power control that adjusted engine throttle with automatic adjustment of engine speed through a mechanical linkage to the propeller constant speed unit. The system was set to maintain approximately 2,500 RPM at cruise power settings and 2,700 RPM at full power. 

The aircraft was also equipped with an oxygen system to allow the pilot to operate over 10,000 ft in the unpressurised cabin. A fingertip oximeter was located in the cabin after the accident. 

Conventional flight controls are operated mechanically by a single-handed side control yoke and rudder pedals. Pitch and roll trim was provided through adjustment of the neutral position of a compression spring cartridge by means of an electric motor in each control system. These were intended to allow easy override of full trim or autopilot inputs by using normal control inputs. Pilot control was effected by movement of a conical trim button on the control yoke.  

Yaw trim is provided by a spring cartridge in rudder control system that provided a centralising force, regardless of the direction of rudder deflection. This was not adjustable in flight.

Avionics and instrumentation

The aircraft was equipped with the Cirrus Perspective Integrated Avionics System developed by Garmin. Flight instrumentation, position, navigation, communication, and identification information were displayed through a primary flight display (PFD) and a multifunction display (MFD). An automatic flight control system (AFCS) provided flight director, autopilot, yaw damper, and manual electric trim functions.    

Indicated airspeed is displayed on the PFD by a moving tape with a rolling number gauge. The colour-coded tape showed the low-speed range as a red strip up to the low-speed awareness velocity (VLSA). An airspeed trend vector in the form of a variable-length magenta vertical line showed the projected indicated airspeed in 6 seconds (for constant rate of acceleration or deceleration). When selected on, V speeds such as V_x (best angle of climb) and V_y (best rate of climb) were displayed next to the airspeed scale. 

Key engine parameters are displayed on the left side of the MFD during normal operations, including analogue style power indication (percentage) and numeric values for power, RPM and manifold pressure. 

A carbon monoxide detector generated a CO LVL HIGH annunciation when the carbon monoxide level was greater than 50 ppm.  

The aircraft was equipped with an electro-pneumatic stall warning system to provide audible warning of an approach to an aerodynamic stall. At approximately 5 kt above the stall (full flaps, power off, level flight) and slightly higher in turning and accelerated flight, a warning horn will sound and a red stall warning annunciation will illuminate.    

Electronic stability and protection is an optional feature to discourage exceedance of attitude, airspeed and angle of attack parameters through corrective control pressures. This will only function above 200 ft above ground level and when the autopilot is off.   

An aircraft data logger system acquires serial information from the primary integrated avionics unit and transmits it to the recoverable data module located in the vertical stabiliser. The PFD and MFD had the capability to record flight and engine data on SD cards. 

Occupant safety features 

A composite roll cage within the fuselage structure provided roll protection for all occupants. The lower firewall was designed to improve crashworthiness. The seat bottoms have an integral aluminium honeycomb core designed to crush under impact to absorb downward loads. Integrated seat belt and shoulder harness assemblies with inertia reels were provided for each occupant. The front seats utilised a 4-point inflatable restraint system. 

An inflatable shoulder harness is integral to each front seat harness. In the event of a collision, the sensor evaluates the force pulse and sends a signal to an inflator assembly mounted in the aft seat frame. This signal releases the gas in the inflator and rapidly inflates the airbag within the shoulder harness cover. 

As is standard for SR series aircraft, the aircraft was equipped with a Cirrus Airframe Parachute System (CAPS). Cirrus Aircraft reported that there had been 124 CAPS Saves (deployments) that resulted in 254 lives saved. CAPS consisted of the following primary components: 

• parachute
• solid-propellant rocket to deploy the parachute
• rocket activation handle and cable
• harness embedded in the fuselage structure.

The parachute and rocket were located in a compartment behind the rear baggage compartment. The rocket activation handle was mounted in a cabin ceiling enclosure between the 2 front seats and the cable was routed through the cabin ceiling and angled towards the left side of the CAPS compartment.   

To initiate the CAPS, the pilot removes the access cover and pulls the rocket activation handle out and down. Movement of the cable compresses the igniter steel spring and cocks the plunger. When one half-inch of plunger travel is reached, the primary booster is ignited, which then ignites a secondary booster and the rocket motor. For aircraft with electronic ignition for the booster, both aircraft batteries are connected to the system and either can actuate the booster in response to cable movement.           

Once ignited, the rocket impacts and dis-bonds the parachute compartment cover situated behind the rear cabin window and pulls the deployment bag from the enclosure. The deployment bag then stages the suspension line deployment and inflation of the parachute. 

On the upper fuselage, either side of the CAPS rocket cover was a placard approximately 16.5 cm long (Figure 4).

Figure 4: CAPS Placard 

Source: Cirrus SR22 POH         

Maintenance

The last 100-hour/annual inspection was completed on 13 January 2023 when the aircraft total time in service was 857.1 hours. According to the aircraft log book, the annual inspection was carried out in accordance with the Cirrus SR22 aircraft maintenance manual and included:

• scheduled inspection of the oxygen system
• scheduled inspection and check of the autopilot servos
• software update to Perspective Avionics
• MFD lower SD card slot and card contacts cleaned (due to supplemental data intermittently unavailable)
• scheduled check of the aircraft data logger system (RDM).   

The scheduled check of the aircraft data logger system involved accessing the diagnostic LED and confirming that the rate and duration of the LED blinking indicated normal operation. According to the maintenance organisation, this was carried out with nil defects identified.         

The only subsequent maintenance was carried out on 15 March 2023 at 887.1 hours total time in service. In response to pilot concern about uneven EGT burn at altitude, the maintenance organisation checked the magneto timing and found it within limits. And as engine data showed a spark plug irregularity, those plugs were cleaned, tested, and reinstalled.   

Cirrus first responder information

The aircraft manufacturer produced a comprehensive Cirrus 1^st Responder Information Manual to inform emergency services of the potential hazards they may encounter when working on or around a Cirrus aeroplane at an accident site. This focussed on CAPS and addressed other hazards such as oxygen bottles, airbag seatbelts, and composite materials. The manual and other safety information including a video was available at Cirrus First Responders (cirrusaircraft.com). In addition, Cirrus Aircraft advised that they had trained thousands of first responders in on-site and classroom contexts.        

According to the manual, it is imperative that the presence of an airframe parachute system be identified as early as possible when responding to an aviation mishap and the system disabled to make it safer to work around. In certain circumstances it may be advisable to secure an accident site and have a Cirrus trained technician attend to disable or disarm the system prior to proceeding with recovery efforts.

Of particular concern is the activation cable routed through the cabin roof that can be altered or stretched during an accident sequence and/or rescue and recovery. This can occur with the activation handle safety pin inserted. On a diagram of the aircraft, the cable route and parachute compartment were identified as a do not cut zone (Figure 5).

Figure 5: Diagram extracted from Cirrus 1^st Responder Information Manual - Activation handle and cable hazards

Source: Cirrus 1^st Responder Information Manual, Date: July 23, 2018, Revision: 2

If the rocket is launched, it accelerates to over 100 mph (160 kmh) in the first tenth of a second, making it a projectile hazard to anyone in its path. Normal trajectory of the rocket is upward and rearward over the tail but damage to the aircraft and nearby obstacles in the flight path can render the trajectory unpredictable.    

For an intact aircraft, CAPS can be secured by inserting a safety pin into the activation handle and handle holder. If an aircraft is not intact, CAPS should be disabled by cutting the activation cable as close to the igniter assembly as practicable (Figure 6). This is a temporary measure that decreases the risk of inadvertent ignition substantially enough to proceed with rescue efforts. Additionally, for an electrically fired system, aircraft batteries can be disconnected, and the igniter wires shunted. 

CAPS can be disarmed by trained and authorised technicians, which renders the rocket, igniter, base, and reefing line cutters inert. 

In response to ATSB request for data about unintentional post-impact rocket activations, Cirrus Aircraft advised that there was limited data as most of these events were not recorded. A few rocket activations had resulted from exposure to direct flame or heat soaking in post-impact fires. 

Figure 6: Image extracted from Cirrus 1^st Responder Information Manual showing rear cabin (looking rearward; carpeting and panels removed), warning placard, and cable cutting location 

Source: Cirrus 1^st Responder Information Manual, Date: July 23 2018, Revision: 2

Accident site and wreckage information

Images of the accident site and wreckage (after recovery of the pilot) were provided to the ATSB. Those images show that the aircraft came to rest on the grass about midway between runway 11 Centre and 11 Left. It was inverted and oriented on the same general heading as the runway.

About 100 m from the threshold of the runway was a white scrape mark on the centreline consistent with a tail strike. A further 230 m along the runway, a series of ground marks started from 30 m to the left of the runway centreline and extended 16 m away from the runway until the main wreckage site. These ground marks were consistent with left wing tip, left wing, and main nose down impact.   

The left wing had broken in 2 places and those pieces were detached from the main wreckage at the wing root. The nose of the aircraft was severely damaged, and 2 propeller blades had sheared off at the hub. Although the propeller blades were damaged, there was no plastic deformation that might indicate engine power at impact because the blades were composite material.   

Some of the left fuselage was cut away and it is likely there was some alteration to the internal conditions around the pilot’s seat as part of the recovery of the pilot. There was significant intrusion of the instrument panel into the cabin. The cabin space was mostly intact, although there was apparent deformation and reduction of cabin height. 

The pilot’s seat was in location but both outboard seat feet had torn the flanges from the outboard seat track at the mid‑seat position due to impact forces and track deformation. The pilot’s seat belt airbags had inflated.   

Depending on observer perspective, the CAPS warning placard was visible on the left rear inverted fuselage (Figure 7). Because of the tilt of the wreckage, the right-side placard was not as visible.  

Figure 7: Wreckage (inverted) at accident site showing CAPS warning placard on left rear fuselage 

Source: NSW Police (annotated by ATSB)

The ATSB examined the wreckage after it was removed from the accident site and secured in a hangar. By that stage the CAPS rocket had been disarmed and removed.   

A search for SD cards located 2 Garmin cards and an SD data card from the MFD. The PFD screen had detached from the instrument panel during the accident and no associated SD card was found. The Garmin cards were not designed to record data and the SD data card was not formatted properly to enable storage of information.   

The recoverable data module (RDM) was intact and removed from the vertical fin for data recovery. The ATSB connected to the RDM but was unable to download any data. After consultation with Cirrus Aircraft and the National Transportation Safety Board (NTSB), the RDM was sent to the NTSB data recovery specialists. They confirmed the ATSB nil result then transferred the memory chips to a surrogate RDM. This allowed data to be downloaded but the RDM had not been recording data since at least 2012. 

Examination of the aircraft identified that the:

• elevator trim setting was neutral
• wing flap selector was in the 100% down position
• oxygen controller was off but there were indications it had been used.

Fire and rescue 

Bankstown Airport did not have an aviation rescue fire fighting facility and it was not a regulatory requirement for that airport. The emergency response to an aircraft accident on Bankstown Airport included Fire and Rescue NSW (FRNSW), which is the State Government agency responsible for the provision of fire, rescue and hazmat services in cities and towns across New South Wales. FRNSW advised that all fire and rescue personnel received the same training and had access to guideline support documents that addressed aircraft incidents including ballistic parachutes. In addition, firefighting crews with an aerodrome/airport as part of their risk profile would be familiar with that environment and take part in emergency exercises. 

Flight path information

The ATSB obtained automatic dependent surveillance broadcast (ADS-B) data transmitted from the aircraft’s Mode S transponder during the flight. That data included altitude, indicated airspeed, and rate of descent, and the approximate distance to the runway threshold was derived from aircraft coordinates (Table 2).       

Table 2: Selected ADS-B data for final approach

* There were a number of data points around 0 ft altitude so the range of airspeed and rate of descent around the initial touchdown is provided. Cirrus noted that the last recorded airspeeds were low and may have been a factor in the bounced landing and aircraft response in the go‑around.

Based on the derived distance data, from 500 ft the aircraft was close to a 3° descent profile, which became about 2.5° after 300 ft.  

In the landing configuration, the stall speed in steady flight was 62 kt (at unfavourable weight and balance conditions).              

Other Cirrus SR22 go-around occurrences

AO-2015-110 Collision with terrain involving a Cirrus SR22, VH-OPX, near Moree, New South Wales, on 17 September 2015. 

The pilot was landing at a private airstrip 10 km north of Moree. Based on observations at Moree and the runway direction, the wind was a quartering tailwind/crosswind from the right of up to 20 kt with small gusts up to 22 kt. 

After a normal approach and extension of full flap, the pilot commenced the flare for landing at about 80–90 kt. To align the aircraft with the runway, the pilot reported applying almost full left rudder and right aileron due to the crosswind. The right main landing gear touched down first, and the aircraft bounced back into the air. The pilot immediately applied full power to initiate a go‑around. However, the left wing dropped and the aircraft yawed to the left. The aircraft’s left wing and propeller then collided with a dam wall. The aircraft stopped abruptly and spun around. The engine separated from the aircraft and came to rest about 20 m away, the tail broke off and the nose landing gear collapsed. The pilot suffered minor injuries, and the aircraft sustained substantial damage.   

AO-2018-038 Loss of control and collision with terrain involving Cirrus SR22, VH-PDC, at Orange Airport, New South Wales, on 15 May 2018. 

The pilot (aircraft owner) and flight instructor were conducting night circuits as the first part of training for a night endorsement. Wind conditions were reported as light and variable. 

On the second approach, the pilot flared the aircraft a ‘little high’ for the touchdown, and the aircraft bounced twice. The pilot elected to go-around and applied full power before touching down again. The ATSB report identified that as the pilot applied full power to perform the go-around, the aircraft pitched nose-up and rolled to the left.

This report also identified 2 other accidents involving SR22 go-arounds in the United States where the aircraft nose pitched up and the aircraft veered left after full power was applied to the engine. (Report ERA12FA540, and Report NYC07CA010)

Previous CAPS hazard safety action

In the past, the ATSB produced a publication Hazards at Aviation Accident Sites: Guidance for Police and Emergency Personnel which was distributed as a booklet. The printed version is no longer available and at the time of writing the investigation report, a pdf copy was available while a digital version was under development. 

When the final report for AO-2018-038 was released the ATSB released a news item with a safety message about the risks associated with post-impact deployment of the CAPS rocket. Flight Safety Australia magazine, produced by CASA, also published an article warning readers to beware of the rocket in the wreckage.

Safety analysis

Attempted landing and loss of control 

En route, approach and landing

The flight path from Southport to final approach at Bankstown was steady with no indication of problems and there was no report of any anomalies regarding radio transmissions. Given the oxygen system was used, there is low risk that the pilot was exposed to hypoxia when operating above 10,000 ft.     

After reporting inbound at Prospect Reservoir in accordance with standard procedures, the pilot responded appropriately to controller advisories. When the pilot acknowledged the clearance to land, which was the last transmission from the pilot, there was no discernible indication of any stress or impairment.     

After joining final approach at 950 ft, the pilot maintained a direct, steady track to the runway and the descent profile was close to a standard 3° approach profile. Although some witnesses reported the aircraft speed was slower than expected on approach, the transmitted data indicated that the aircraft was at the Cirrus‑recommended approach speed of 80 kt (indicated airspeed) by 300 ft. Based on the flight data, the approach was consistent with the Cirrus stabilised approach criteria.

Below 100 ft, the airspeed reduced to between 71 and 61 kt but given the fidelity of the data it is not possible to establish the speed at the initial touchdown or subsequently. As Cirrus indicated, low airspeed just before landing may have been a factor in the occurrence.      

In the CCTV imagery, the aircraft appeared to sink onto the runway and witnesses observed the aircraft bounce along the runway. After the initial bounce, the aircraft tail scraped on the runway, which was symptomatic of the unstable landing without any effect on the subsequent controllability of the aircraft. 

Although there was a crosswind component, it was well within the capability of the aircraft and expected to be within the capability of the pilot. There was also no indication from the aerodrome forecast and observations, or from other pilots on approach to adjacent runways, of any significant wind gusts or turbulence affecting the landing. 

Landings are dynamic, skill-based manoeuvres that rely on pilot judgement of existing and projected energy state with sensitive adjustment of aircraft attitude and engine power. The unstable landing was consistent with a misjudged flare. Pilots can recover by adjusting the aircraft energy and attitude for another attempt to land or by initiating a go-around.    

Loss of control

About 5 seconds after the initial touchdown, the aircraft came off the ground and immediately rolled into a climbing steep left turn up to a height of about 40 ft then dropped and impacted the ground on the left wing and nose.

As there was no recorded flight or engine data, there was no direct information about the engine power settings during the accident sequence. The pilot did not transmit his intentions however, in the context of landing difficulties and trying to control the aircraft, a radio call would not be expected.  

Based on the CCTV and witness information, the performance of the aircraft as it lifted off and entered the climbing turn was consistent with high engine power. It follows that the pilot had intentionally initiated a go-around as recovery from the unstable landing.

A mild pitch up would be expected in the early stages of go-around from a bounced landing to maintain ground clearance. However, the large pitch up that was observed was not consistent with the recommended go-around procedure to pitch up to a level attitude and begin accelerating to the speed consistent with either V_x (best angle of climb) or V_y (best rate of climb). It is likely that application of high engine power exacerbated the effects of nose-up control inputs. The Cirrus SR22 is equipped with a relatively high-power engine for a 4-place aircraft. Although turbo‑normalising the engine does not increase the maximum rated power of the engine, it was reported that there could be a noticeable ‘surge’ as the throttle was advanced on the ground.  

Application of high engine power will produce ‘torque’ that will result in a strong left turning tendency. This effect is magnified by low airspeed and a high pitch angle. The rate of throttle control movement and engine response will also influence torque characteristics and associated controllability.  

In normal operational contexts where high or full engine power is applied at the recommended rate, the pilot is able to counteract torque effect through coordinated use of steering (on the ground), and use of rudder and aileron once airborne. However, in this case, the torque effect was probably stronger than experienced during normal operation and the effectiveness of the flight controls was compromised by the low airspeed. Consequently, the pilot lost directional control of the aircraft early in the go-around sequence and was unable to recover.    

As the angle of bank increased in the turn away from the runway, the stall speed increased, and the vertical component of lift generated by the wings decreased to zero as the aircraft reached a 90° angle of bank. Consequently, the aircraft dropped out of the turn. 

The ATSB investigated 2 previous Cirrus SR22 go-around accidents at Moree in 2015 and Orange in 2018. Although the reports identified other factors that played a role in those occurrences, it is likely that torque effect played a key role in each loss of control.     

To summarise: In the early stages of a go-around from an unstable landing, the pilot was unable to counter the substantial torque effect associated with high engine power, low airspeed, and high pitch angle. As a result, when the aircraft came off the ground, it rolled into a climbing steep left turn up to a height of about 40 ft then dropped and impacted the ground on the left wing and nose. 

Go-around safety considerations

A go-around is a transition from a low-power condition while descending/landing to a high-power climb. When this occurs during an approach, the aircraft has potential and kinetic energy and in visual conditions there is generally no urgency to carry out the procedure. In contrast, when a pilot does a go-around from an attempted landing, the aircraft is in a low energy state and there is typically some urgency to initiate the procedure to recover from an unstable state on or close to the ground.     

Flight training and reviews include go-arounds and the pilot had recently completed an instrument proficiency check that included missed approaches. As this check, and the preceding attempted check with associated training, was carried out by a Cirrus Standardised Instructor Pilot in the pilot’s SR22, the pilot was familiar with the type-specific characteristics of missed approaches. The instructor had also conducted practice go-around sequences at safe altitudes with the pilot.  

This training and assessing is essential but has an inherent limitation because it is not feasible to simulate the conditions experienced during recovery from an unstable landing. It is possible that the pilot had not previously encountered a go-around from a rejected landing and was not prepared for the aircraft response to engine power in that context.        

The balked landing/go-around procedure in the POH specified a sequence of 5 actions/parameters. Although this was applicable to all phases of flight, it did not provide any guidance for conduct of the procedure in different conditions. 

To supplement the POH, Cirrus produced a flight operations manual and training videos that addressed approach, landing, and go‑arounds in SR20/22 aircraft. These resources provided useful guidance that was oriented to go‑arounds during final approach. It is not known if the pilot had referred to the guidance in the flight operations manual and there was no record of the pilot having directly accessed training videos for go-arounds, although some videos were freely available without a subscription.  

The Cirrus procedure and the more detailed flow for go-arounds was conventional and applicable to the occurrence scenario with careful implementation from memory so control could be maintained during the recovery and transition into a climb. However, the ATSB noted that the material provided by Cirrus did not highlight the risk of loss of control associated with a go-around during the landing phase, where there was high engine power, low airspeed, and high pitch attitude. 

CAPS hazard  

Cirrus Aircraft advised that 254 lives have been saved due to the CAPS system. However, notwithstanding the benefits, CAPS also presents a serious post-accident hazard when it has not been deployed and the aircraft is damaged. If the rocket is inadvertently activated, anyone in its path would be seriously or fatally injured.

Cirrus Aircraft had been actively managing this risk by providing training to first responders (in the United States) and producing a detailed manual for first responders that is freely available on a dedicated website. In Australia, the ATSB has published and distributed a booklet for emergency services that addressed the risk of ballistic parachute systems in various aircraft types, including the Cirrus SR20/22. After the Cirrus SR22 accident at Orange in 2018 when the rocket was activated by the post-impact fire, the ATSB produced a video about the CAPS hazard and Flight Safety Australia magazine published a related article. 

The only external indication of the CAPS hazard on the aircraft is a warning placard either side of the rocket exit point. These are not prominent and did not feature symbology or colour that are recognised indicators of danger. In addition, there are no markings to identify the no-cut area associated with the activation cable. On this occasion, the placards were not easy to identify or read because the aircraft was inverted. 

Despite the availability of online guidance for first responders to a Cirrus aircraft accident, placards on the aircraft, and RFNSW training/education, the emergency services site commander was not aware of the presence of the airframe parachute system until advised after the rescue had started. At that point, while the site commander was aware of the rocket hazard, they did not know how to access information about the activation mechanism and method to secure the system. All first responders from FRNSW should have an awareness that aircraft might be equipped with a rocket propelled parachute system and the associated risks but it is not feasible for them to have type‑specific knowledge.   

As the accident was at a major general aviation airport on a weekday and during standard working hours, there were aircraft maintenance personnel with knowledge of Cirrus aircraft that were available to assist with securing of the CAPS. They informed emergency personnel about the activation mechanism and secured the handle, which helped to reduce the risk of rocket activation. The risk could have been reduced further if the system had been secured by cutting the activation cable and, if the conditions had allowed, disconnection of the 2 batteries.

If the rocket had been inadvertently activated while the fuselage was inverted, the path of the rocket would have been uncertain and the release of heat and energy in the presence of fuel would have been a significant fire risk. 

Cirrus advised first responders that it is imperative that the presence of an airframe parachute system be identified as early as possible, and the system disabled to make it safer to work around. In support of these imperatives, Cirrus provided training, education, and aircraft placards. However, the ATSB considered that the training and education had limited reach, and the placards did not effectively communicate the danger or provide access to safety information.

The ATSB considered that these limitations increased the risk of injury during the recovery of the pilot in this occurrence. Given no recorded incidents of post-impact rocket activations unrelated to fire, and the variability of aircraft accidents and associated damage, the ATSB did not identify this as a safety issue. Nevertheless, the ATSB supports any enhancement to the post-accident identification of CAPS and disabling of the system to reduce the risk of injury.    

Findings

From the evidence available, the following findings are made with respect to the loss of control and collision with terrain involving Cirrus Design Corporation S22 at Bankstown Airport, New South Wales on 17 March 2023.  

Contributing factor

• In the early stages of a go-around from an unstable landing, the pilot was unable to counter the substantial torque effect associated with high engine power, low airspeed, and high pitch angle. As a result, when the aircraft came off the ground, it rolled into a climbing steep left turn up to a height of about 40 ft then dropped and impacted the ground on the left wing and nose. 

Other factors that increased risk

• The first responders were initially unaware that the aircraft was equipped with a ballistic parachute (CAPS) and initiated the recovery of the pilot with the system still armed. By not securing the CAPS, the risk of inadvertent rocket activation and injury was increased.
• Cirrus Aircraft provided training, education, and placards to reduce the risk of inadvertent post‑accident actuation of the ballistic parachute (CAPS) rocket and associated injury. However, the training and education had limited reach, and the placards did not clearly communicate the danger or provide access to safety information. 

Safety actions

Safety action by Cirrus Aircraft

Cirrus Aircraft advised that they have enhanced the external CAPS placarding on 2 new models of aircraft (the SF50, and another in development) to align with current American Society for Testing and Materials (ASTM) standards (Figure 8). The SR2X series of aircraft (the SR20, SR22, and SR22T) were certified prior to the implementation of ASTM standards. At the time of writing, Cirrus was reviewing the possibility to enhance the placard that was certified with SR2X.

Figure 8: Example of an ASTM Standard CAPS Placard used on the SF50 Vision Jet

Source: Cirrus Aircraft

During the draft report review process the ATSB sought input from Cirrus as to whether there was an opportunity to enhance the safety benefit of their go‑around training and educational products, especially in regard to the SR22 models that are equipped with relatively high-power engines during the landing phase.

Cirrus did not advise of any associated safety action. 

Sources and submissions

Sources of information

The sources of information during the investigation included:

• the aerodrome controller
• accident witnesses
• the New South Wales (NSW) Police Force
• the Fire and Rescue NSW onsite commander
• Aeria Management Group (Bankstown Airport)
• Airservices Australia
• Civil Aviation Safety Authority
• the flight examiner
• Cirrus Aircraft
• the maintenance organisation for VH-XGR

References

Pilot’s Handbook of Aeronautical Knowledge FAA-H-8083-25C

Submissions

Under section 26 of the Transport Safety Investigation Act 2003, the ATSB may provide a draft report, on a confidential basis, to any person whom the ATSB considers appropriate. That section allows a person receiving a draft report to make submissions to the ATSB about the draft report. 

A draft of this report was provided to the following directly involved parties:

• aerodrome controller
• Fire and Rescue NSW onsite commander
• Aeria Management Group (Bankstown Airport)
• Civil Aviation Safety Authority
• Flight examiner
• Cirrus Aircraft
• maintenance organisation for VH-XGR

Submissions were received from:

• Civil Aviation Safety Authority
• Cirrus Aircraft

The submissions were reviewed and, where considered appropriate, the text of the report was amended accordingly.

Purpose of safety investigations The objective of a safety investigation is to enhance transport safety. This is done through:  identifying safety issues and facilitating safety action to address those issues providing information about occurrences and their associated safety factors to facilitate learning within the transport industry. It is not a function of the ATSB to apportion blame or provide a means for determining liability. At the same time, an investigation report must include factual material of sufficient weight to support the analysis and findings. At all times the ATSB endeavours to balance the use of material that could imply adverse comment with the need to properly explain what happened, and why, in a fair and unbiased manner. The ATSB does not investigate for the purpose of taking administrative, regulatory or criminal action. Terminology An explanation of terminology used in ATSB investigation reports is available here. This includes terms such as occurrence, contributing factor, other factor that increased risk, and safety issue. Publishing information Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2024 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

Executive summary

What happened

On 26 December 2022, a Stoddard Hamilton Aircraft Glasair Super II FT, registered N600, departed Temora, for a private flight to Wedderburn aircraft landing area, New South Wales. On arrival at Wedderburn, N600 conducted a landing and go-around on runway 17. During the go‑around, N600 failed to achieve sufficient climb performance and impacted terrain about 2.7 km to the south-west of Wedderburn. The aircraft was destroyed, and the two pilots on board were fatally injured.

What the ATSB found

The ATSB found that N600 conducted an approach to land on runway 17 with a quartering tailwind and subsequently conducted a go-around after touch down. For reasons that could not be determined, N600 did not achieve a sufficient climb performance after take-off which led to a collision with terrain.

The ATSB also found that both pilots on board did not have recent experience in single-engine, automotive engine conversion, amateur-built aircraft or the Glasair in general.

Additionally, the pilots elected to operate the aircraft from Bankstown to Temora for the aircraft’s first flight in Australia, even though the special flight authorisation did not permit operations over built-up areas.

It was also found that N600 was fitted with propeller pitch change rocker switches on the left and right side of the throttle which were reversed in orientation for each flight crew member. This increased the risk that a pilot flying from the right seat could operate the propeller pitch change opposite to the intended selection.

Safety message

Pilots intending to operate amateur-built aircraft should be aware of the potential differences in systems and controls to that of conventional type-certified aircraft. They should also consider transition training onto the same aircraft type, or aircraft with similar design features and performance capabilities.

Pilots attempting to conduct post-maintenance proving flights in amateur-built aircraft are urged to be proficient in the specific aircraft emergency operations, particularly those related to partial power failures. It is also prudent to select an appropriate aerodrome and benign weather conditions to conduct familiarisation flights, to safely expand their operational experience.  

When a formal flight plan is not lodged, leaving a flight note with a responsible person who is able to notify the appropriate authorities should the flight become overdue is also an important safety consideration.

Understanding the safety implications of regulatory permissions is vital so that experimental aircraft operations do not adversely affect the safety of third parties, such as other airspace users and people on the ground not associated with the operation of the aircraft.

The investigation

The occurrence

On the morning of 26 December 2022, a Stoddard Hamilton Aircraft Glasair Super II FT, registered N600, was operated on a private flight under the visual flight rules (VFR)[1] from Bankstown to Temora, then onto Wedderburn, New South Wales. The aircraft was registered in the US, and this was the aircraft’s first flight in Australia, and its purpose was to reposition the aircraft to Wedderburn. The two pilots were both co-owners of the aircraft. Air traffic control audio recorded the aircraft departing Bankstown at about 1003 local time.

Flight tracking data (Figure 1) showed the aircraft being flown to Temora, landing at about 1133. The aircraft was then refuelled and conducted 2 circuits[2] before departing about an hour later for Wedderburn, which was expected to be its planned destination.

Figure 1: Flight tracking data from N600 on 26 December 2022

Source: Google Earth, ADS-B Exchange, FlightRadar24 and OzRunways, annotated by the ATSB

On arrival at Wedderburn, N600 was positioned on a wide circuit and landed on runway 17[3] at about 1452. The pilot then conducted a go-around[4] and the aircraft became airborne again.

Witnesses at Wedderburn observed the aircraft in a shallow climb, climbing just enough to clear rising terrain and trees at the end of runway 17. After clearing the trees, the aircraft disappeared from view below the ridgeline. About 2 minutes later, N600 collided with terrain about 2.7 km from the end of the runway, and about 150 m from Appin Road (Figure 2), about 1.4 km to the south‑east of Appin township.

The wreckage was consumed by a post-impact fire that also started a small bush fire. Both occupants were fatally injured.

Figure 2: ADS-B Exchange flight data showing the landing and go-around at Wedderburn aircraft landing area and the location of the collision with terrain

Source: Google Earth and ADS-B Exchange, annotated by the ATSB

Context

Pilot Information

For clarity, as there were 2 pilots on board N600, this report will identify them individually as ‘Pilot A’ and ‘Pilot B’. Witnesses confirmed that it was the intention that Pilot B would be in command for the flight from Temora to Wedderburn, however the exact seating positions and pilot in command for the accident flight are unknown due to the nature of the accident sequence.

To operate N600, a pilot was required to hold a valid US licence. Both pilots had obtained their United States Federal Aviation Authority (FAA) qualifications based on their previous Australian pilot licences and aviation medical certificates, however recent flight times and current FAA flight reviews were unable to be located.

Pilot A

Licencing and aeronautical experience

Pilot A was experienced in multi-engine fixed wing operations. They were operating N600 for the first time that day. Their FAA Private Pilot (Aeroplane) Licence was issued on 16 July 2009, however there are no records of an FAA single-engine aeroplane flight review since initial issue of the FAA licence based on their Australian qualification.

They held a Civil Aviation Safety Authority (CASA) Air Transport Pilot (Aeroplane) Licence (ATPL(A)) that was re-issued on 22 January 2015. Recent pilot logbooks were unable to be located, however an electronic logbook file from December 2021 showed a total flying experience of 2,697 hours, of which almost 2,212 hours were in multi-engine aircraft.

The pilot had completed a CASA multi-engine flight review on 7 March 2021, which was valid to 31 March 2023. They had operated N600 for a number of ground runs in preparation for the first flight and was reported to have operated N600 from Bankstown to Temora on the day of the accident. The pilot held an RAAus pilot certificate, however it is unknown how much experience the pilot had with high performance single-engine aircraft. A witness identified that the pilot had previously flown a Glasair aircraft prior to the purchase of N600, however this was unable to be identified in the pilot’s logbook.

Medical

Pilot A held a valid CASA Class 2 aviation medical certificate, which was issued with restrictions that required distance correction and reading correction to be available whilst exercising the privileges of the licence.

Pilot B

Licencing and aeronautical experience

Pilot B was also experienced in multi-engine fixed wing operations, and operated N600 for the first time that day at Temora.

They held a CASA ATPL(A) that was issued on 29 April 1991. A recent pilot logbook was unable to be located, however the latest logbook identified (from July 1996 to August 2004) recorded a total flying experience of 6,156 hours, of which only 761 hours were in single-engine aircraft, with the last recorded single-engine flight in September 1999.

FAA records indicate that Pilot B received an FAA Commercial Pilot Certificate on 5 January 1990, based on their Australian licence however there are no records of an FAA single-engine aeroplane flight review since initial issue of the FAA licence based on their Australian qualification. CASA records indicate that the pilot had last completed a multi-engine aeroplane flight review on 7 March 2021 which was valid until 31 March 2023, there was no record of any single-engine flight reviews for either CASA or FAA licences.

Due to limited recorded flight hours for Pilot B, it was unable to be determined if the pilot had flown the aircraft type previously.

Medical

Pilot B previously held a CASA Class 2 aviation medical certificate which had expired on 18 November 2022. The Class 2 was issued with a restriction that reading correction must be available whilst exercising the privileges of the licence.

Aircraft Information

General

N600, serial number 2277, was a Stoddard Hamilton Aircraft Glasair Super II FT, amateur-built aircraft[5] constructed in the US. The aircraft was a high performance, conventional two-seat, single-engine, low-wing monoplane with tricycle undercarriage, built mostly of fibreglass. The aircraft was fitted with a Subaru EJ-25 automotive engine, modified for aviation use by NSI Propulsion Systems (later Maxwell Propulsion Systems). N600 had an initial Special Airworthiness Certificate issued on 30 April 2014. The first flight was conducted on 4 June 2014 in the US. About 59 hours flight time was accumulated before the aircraft was imported into Australia in 2021.

Prior to leaving the US, the aircraft was disassembled to facilitate shipping. Subsequently, upon arrival in Australia, significant work was undertaken to restore the aircraft to an airworthy condition.

Airworthiness and Maintenance history

The last recorded maintenance work in N600’s maintenance log was on 12 May 2016. Maintenance had continued to be recorded in the aircraft log up until disassembly on 28 April 2021.

After shipping to Australia in July 2021, N600 was reassembled in Bankstown by a CASA approved maintenance facility. When the maintenance facility was notified by the owners that N600 would remain on the US FAA register, an FAA certified Airframe and Powerplant (A&P) technician performed an airworthiness inspection in accordance with Federal Aviation Regulation 43, Appendix D.

During the disassembly process in the US, several electrical wiring looms were cut to facilitate the removal of the wing from the fuselage. An authorised repair facility performed the electrical reconnection and required inspections. No engine work was performed during the reassembly. The aircraft was released for service on 14 September 2022 by the FAA A&P. 

No record of any periodic maintenance was identified since its original test flying and the aircraft had accrued about 59 hours total time in service.

Engine and propeller speed reduction unit

The Subaru EJ-25 is a 4-cylinder, liquid-cooled, fuel-injected automotive engine, fitted with a single electronic ignition. The engine throttle control was controlled by a single cockpit tee handle throttle, mounted in the centre console between the two seats, operating a cable to the fuel control unit (Figure 3).

The propeller speed reduction unit (PSRU) was mounted to the front side of the engine and had a speed reduction gearing of 2.1:1. The PSRU contained a sprag clutch to dampen engine harmonics.

Detailed laboratory examination of the engine and PSRU did not indicate any pre-impact or mechanical abnormalities that may have contributed to the accident. However, due to the fire affected engine components, much of the ignition and electrical system were consumed by the post-accident fire, and therefore were unable to be tested.

Propeller

N600 was fitted with a Maxwell Propulsion Systems CAP-220 two-blade, electric variable pitch propeller, with an alloy hub. The carbon fibre propeller blades were manufactured by Whirlwind Propellers.

Propeller pitch change control (Figure 3) was achieved with two rocker switches (one for each crew seat) mounted on either side of the throttle tee-handle lever, activating the electric pitch change motor. It took about 10 seconds to cycle between the course and fine pitch stops. The rocker switches were identical in their design and operation, in that when viewed directly on, the left side of the switch had the increase pitch selection (+), and the right side had the decrease pitch selection (-). This meant that if the switches were wired in accordance with the ‘+’ and ‘-‘ labelling, the switches would be actuated in opposite directions relative to each pilot’s seated position to achieve the desired propeller pitch change. The switch orientation and wiring was confirmed by the original aircraft builder as being wired correctly to the switch orientation when the aircraft was constructed.

Figure 3: Engine throttle tee-handle lever showing propeller rocker switches mounted to each side

Source: FAA A&P mechanic during inspection, annotated by the ATSB

There was no propeller pitch position indicator fitted to the aircraft. The pitch was set by using engine revolutions per minute (RPM) and manifold pressure indications. Pilot operation of the rocker switch electrically adjusted the propeller blades to achieve an optimal RPM and manifold setting for take-off, climb, cruise, approach, and landing.

ATSB performed a disassembly and examination of the electric in-flight adjustable propeller pitch motor and drive unit, which appeared in good condition. No evidence of pre-impact mechanical defects was identified. Some visible corrosion was found, however this was likely due to water used to extinguish the post-impact fire. The propeller pitch was set to about 19.5° and was consistent with other exemplar propeller pitch settings in the take-off configuration (fine propeller pitch) to allow greater acceleration and initial climb performance.

Fuel

N600 operated on aviation gasoline (AVGAS), and held 151 L in the main wing tanks, 76 L in the wingtip extensions, and an additional 26 L in the header tank. Each tank was fitted with a sump and a fuel drain. A fuel selector (Figure 3) was located on the centre console aft of the throttle. The selector had ‘off’ and ‘on’ positions only, and no option to select an individual tank to supply fuel to the engine. 

Fuel records indicate that on 23 December 2022 100 L of AVGAS was uploaded to N600. It is unknown how much fuel N600 had on board at the time of departure from Bankstown, as a number of ground runs had been conducted prior to departing Bankstown for Temora.

On the day of the accident while at Temora, N600 was refuelled with 70.4 L of AVGAS before subsequently departing to Wedderburn.

Fuel residue was unable to be detected at the accident site due to substantial disruption to the airframe and subsequent post-impact fire. Therefore, the amount of fuel on board at the time of the accident was unable to be determined.

Meteorological Conditions

No significant rainfall was observed or recorded within 40 km of Appin around the time of the accident. Closed Circuit Television (CCTV) footage from Wedderburn showed clear skies and an easterly crosswind on runway 17, with a quartering[6] tailwind during the landing and subsequent go-round of N600.

Wreckage information

The accident site was located about 1.2 km to the south-east of Appin township (Figure 4).

Figure 4: Accident site

Image source: ATSB

N600 entered trees on an approximate heading of 237° and the first tree impact was about 50 ft above ground level (Figure 4) at 833 ft above mean sea level. The left-wing tip (fuel tank) was located to the left of that tree, and a piece of the upper left wing was to the right of the direction of travel, most likely as a result of initial tree impact. The aircraft then continued for about 45 m, hitting further trees, before impacting a large rock. The airframe was upright and facing opposite the direction of travel. The main wreckage was spread along a path of about 90 m and was heavily disrupted and fire affected.

Figure 5: Direction of travel N600

Image source: ATSB

During the accident sequence, the engine and propeller assembly had detached from the airframe and came to rest about 10 m further in the direction of travel, and was heavily affected by fire. Initial propeller contact with trees led to both blades separating from the hub. Most of the wreckage was contained within the fire zone with a small fragment of unburnt propeller blade located about 100 m from the initial tree impact point to the right of aircraft direction of travel.

Recorded data

Air traffic control audio recorded N600’s departure from Bankstown Airport at about 1003. Flight tracking data obtained from ADS-B Exchange and FlightRadar24 showed the aircraft being flown to Temora, landing at about 1133. The aircraft was refuelled, and OzRunways data showed that the aircraft then conducted 2 circuits between 1229 and 1246. Flight data shows that the aircraft departed Temora at 1323 and tracked for Wedderburn.

About 1 hour 23 minutes later, N600 joined a wide right downwind for runway 17 at Wedderburn. Wedderburn aircraft landing area has a single runway with a bitumen surface area of about 950 m in length. At about 1452, N600 touched down about 200 m into runway 17 at about 87 kt ground speed and rolled for about 50 m before becoming airborne again.

CCTV at Wedderburn showed the aircraft in a shallow climb, enough to just clear rising terrain and trees at the end of runway 17. After clearing the trees in the vicinity of the airfield, the aircraft then disappeared from CCTV view. Recorded data indicated that about 2 minutes later, N600 collided with terrain about 2.7 km from the end of the runway, about 150 m from Appin Road (Figure 6).

Figure 6: Final track N600

Image source: Google Earth and ADS-B Exchange, annotated by the ATSB

Other information

Amateur-built aircraft

Pilots and passengers of experimental aircraft in Australia accept the risk that the aircraft may not meet the same airworthiness safety standards as certified aircraft and operate these aircraft on the basis of informed participation.[7]

Transition to unfamiliar aircraft

General competency

For a pilot to operate a different aircraft type already covered by their licence category and class rating, they need only be satisfied that they are competent to conduct all normal, abnormal, and emergency flight procedures for the aircraft. They also need to be able to apply operational limitations, conduct weight and balance calculations, and apply aircraft performance data, including take-off and landing performance data, for the aircraft.

Guidance on transition

While no definitive Australian guidance provided advice on the transition of pilots to unfamiliar aircraft, the FAA advisory circular (AC) AC90-109A – Transition to Unfamiliar Aircraft (U.S. Department of Transportation Federal Aviation Administration, 2015) is a widely recognised and utilised publication providing a sound basis to consider the hazards of transitioning to unfamiliar types of aircraft, whether certified or experimental amateur-built.

The AC recognises the importance of providing guidance to pilots transitioning between aircraft types, or to experimental aircraft with differing design features to high performance and complex aircraft. It recommends that pilots should develop a training strategy (Figure 7) for mitigating the risks of operation of an unfamiliar aircraft type.

The FAA AC recommends that:

Prior to flying an unfamiliar airplane, all pilots should review the hazards and risks outlined in this AC, and complete the training recommended before operating the airplane. Accident data has shown that there is as much risk in “moving down” in performance as “moving up.” For example, consider a pilot who has substantial experience in high-performance corporate, airline, or military airplanes. The knowledge and skills used to safely fly at high speeds, high altitudes, and over long flights will, by themselves, not prepare the pilot for the challenges of a low-inertia, high-drag airplane.

Figure 7: FAA recommended airplane transition training approach

Source: FAA AC90-109A

The guidance recommends firstly that pilots should consider undertaking flight training with a qualified flying instructor in the proposed transition aircraft, the same make and model or an aircraft that exhibits the same design features or characteristics of the transition type. If instruction is unavailable, seek another experienced pilot to conduct a familiarisation flight. However, if the instructor is unwilling, at least discuss the differences and expected characteristics of the transition aircraft.

The guidance further recommended that pilots take a risk management approach to formally identify the hazards and mitigate any known or elevated risks identified.

These may include, specific type training in the transition aircraft or similar type/design features, the condition, maintenance and history of the transition aircraft, planning transition flights to conservatively build up manoeuvres and aircraft experience and conducting initial flights in benign weather conditions
 

US registration

It was reported that, to avoid operating under Australian aircraft requirements, the owners decided to leave the aircraft on the US register, and apply on behalf of the registered owner to CASA for a special flight authorisation[8] (SFA) for operations in Australia.

In order for this to occur, the FAA required the registered owner of N600 to have US citizenship. The owners of N600 approached a mutual friend with dual Australian/US citizenship, to act in an administrative role as the registered owner. The owners then applied on behalf of the registered owner to CASA for a SFA in order to operate N600 in Australia.

CASA Special flight authorisation

On 19 October 2022, CASA instrument CASA SA 22/2982 was issued providing a SFA for N600 to operate in Australia under conditions that included that the aircraft be maintained in accordance with the requirements of the FAA. Other operational requirements included that it only be flown in day VFR, must not be operated over populous areas, operated in accordance with CASR Part 91, and only be flown by nominated persons of the registered owner.

Witnesses

A witness at Temora saw N600 at the fuel bowser after conducting circuits, and spoke generally with the pilots by radio about the aircraft. Nothing unusual about the aircraft was observed by the witness prior to its departure from Temora.

The last witness to see the aircraft was at Wedderburn, shortly before the accident, and recalled N600 conducting a go-round after landing and recounted that the aircraft did not climb as expected.

A witness near the accident site just prior to impact recalled the noise of the aircraft reverberating off a nearby water storage tank seconds before impact and described it as ‘revving high and sounded like a machine gun firing’.

Survival aspects

Examination of the aircraft wreckage indicated that the initial impact was in a controlled state at a slow speed, into dense trees. The cabin structure surrounding the cockpit was significantly disrupted during the later stages of the accident sequence, and was not considered survivable.

The carriage of an appropriate emergency locator transmitter (ELT) and/or personal locator beacon (PLB) was a requirement under Civil Aviation Regulation (CAR) 252A unless, among other requirements, the aircraft would be operating within a 50 NM radius from the original point of departure. The ELT fitted to N600 was not compliant with Australian requirements. No crash activation of the ELT was detected or advised by authorities after the accident. A family member identified that one of the pilots was carrying a PLB onboard the aircraft on the day of the accident. However, given the post impact fire and severe degradation of the site, the ATSB was unable to locate the PLB.

Although not legally required, the pilots had not lodged a flight plan or arranged a SARTIME to be held by a responsible person. One of the pilot’s spouses was awaiting the arrival of the aircraft at Wedderburn but was not in receipt of a flight plan or nominated SARTIME.

Safety analysis

On 26 December 2022, a Stoddard Hamilton Aircraft, Glasair Super II FT, registered N600, departed Bankstown, New South Wales for a private flight to Temora, and then onto Wedderburn. N600 conducted a landing and go-around on runway 17 at Wedderburn. However, during the go‑around, N600 failed to achieve sufficient climb performance and impacted terrain about 2.7 km to the south-west of Wedderburn aircraft landing area. The aircraft was destroyed, and the two pilots on board were fatally injured.

This analysis will explore airworthiness considerations pertaining to N600, relating to the engine, reduction gearbox and propeller, the pilots’ experience on the aircraft type, control layout, the approach to land at Wedderburn and general conditions for operation in Australia.  

Climb performance

After conducting a landing and go-around from runway 17 at Wedderburn, N600 encountered reduced climb performance and was unable to sufficiently out climb surrounding terrain for about 2 minutes before contacting trees.

Post-accident review of the aircraft engine could not determine any mechanical discontinuity of the engine or gearbox, however due to fire affected components of the electrical and ignition systems, there was not enough evidence to examine these systems definitively.

CCTV footage indicated a fast but controlled landing at Wedderburn prior to the go‑around.

Witness accounts of high engine power leading up to the impact and the degree of post-impact fire indicates sufficient fuel onboard and no evidence of engine stoppage in flight.

Propeller fragments found at the accident site indicated that the propeller had significant rotational speed at initial impact with trees. Propeller pitch settings at the time of the accident were likely in a setting to facilitate take-off power, however the pitch setting at the time of the go-around could not be determined.

Witness indications of a ‘machine gun noise’ may indicate propeller noise, imbalance or damage prior to the impact, however, as post-impact evidence was mostly consumed by fire these possibilities were unable to be further examined.  

Therefore, with the limitations of evidence, the ATSB could not determine the reasons why the aircraft was unable to sufficiently out climb surrounding terrain.

Pilot experience on amateur-built aircraft

Both pilots had significant experience in larger multi-engine aircraft and neither had flown N600 prior to the day of the accident. While experienced in larger conventional aircraft operations, there was little evidence to support recent flying experience in light, single-engine, or amateur-built aircraft types.

Each amateur-built aircraft by their very nature is unique. The aircraft builder develops their own systems architecture to accommodate their selected components. This may vary significantly to conventional aircraft configurations and systems.

The absence of previous experience on the aircraft type and recent single-engine flying likely did not prepare the pilots for the challenges of managing an emergency on take-off of a single-engine, experimental amateur-built aircraft with particular design, performance, and control differences.

Special flight permit

The owners of N600 operated the aircraft from Bankstown Airport and over populous areas on the morning of the accident. This was not in accordance with condition 6 as detailed in schedule 2 of the special flight authorisation approved and issued by CASA.

Flight over populous areas in aircraft with a non-certified automotive engine, increases the risk of injury and death to third parties not associated with the operation of the aircraft and reduces the emergency landing options available to pilots if an emergency occurs during take-off.

Non-conventional systems in amateur-built aircraft

Amateur-built aircraft traditionally have different attributes to that of certified aircraft. This can sometimes be evident in the control system layouts and actuation. In the case of N600, the propeller pitch rocker switches were reversed in activation orientation from the left to the right seat. Even with prior knowledge of this control layout, it is likely that operating the aircraft from a different seating position would increase the likelihood of inadvertent pitch change reversal in an emergency during a critical phase of flight, although it could not be determined which seat the aircraft was being operated from at the time of the accident.

The absence of a propeller pitch position indicator or visual references to the pitch settings increases pilot reliance on pre-set throttle and pitch settings prior to take-off, which may not be adequately set during a go-around.

Circuit approach and go-around at Wedderburn

The final approach to land at Wedderburn was conducted after a wide circuit on runway 17 without an overhead circuit join, limiting the appreciation of the wind direction on the ground. This likely led to landing with a quartering left-tailwind in hot and gusty conditions, increasing the aircraft’s ground speed for landing. It is likely that this higher ground speed, downwind landing was a significant factor in pilot decision making to conduct a go‑around.
 

Sources and submissions

Sources of information

The sources of information during the investigation included:

• Bureau of Meteorology
• OzRunways
• FlightRadar24
• ADS-B Exchange
• Federal Aviation Administration
• Civil Aviation Safety Authority
• New South Wales Police Service
• Glasair aircraft
• maintenance organisation for N600
• FAA A&P maintainer
• Airservices Australia
• accident witnesses
• CCTV footage

References

Submissions

Under section 26 of the Transport Safety Investigation Act 2003, the ATSB may provide a draft report, on a confidential basis, to any person whom the ATSB considers appropriate. That section allows a person receiving a draft report to make submissions to the ATSB about the draft report.

A draft of this report was provided to the following directly involved parties:

• Federal Aviation Administration
• Civil Aviation Safety Authority
• Airservices Australia
• Bureau of Meterology

No submissions were received from the directly involved parties for changes to the report.

Purpose of safety investigations The objective of a safety investigation is to enhance transport safety. This is done through: identifying safety issues and facilitating safety action to address those issues providing information about occurrences and their associated safety factors to facilitate learning within the transport industry. It is not a function of the ATSB to apportion blame or provide a means for determining liability. At the same time, an investigation report must include factual material of sufficient weight to support the analysis and findings. At all times the ATSB endeavours to balance the use of material that could imply adverse comment with the need to properly explain what happened, and why, in a fair and unbiased manner. The ATSB does not investigate for the purpose of taking administrative, regulatory or criminal action. Terminology An explanation of terminology used in ATSB investigation reports is available here. This includes terms such as occurrence, contributing factor, other factor that increased risk, and safety issue. Publishing information  Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2023 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

Executive summary

What happened

On the afternoon of 30 November 2022, the student pilot of a Hughes Helicopters 269C, registered VH-OBK, was returning to Moorabbin following the pilot’s second solo navigation training flight.

As the helicopter approached the landing area, the approach became unstable, and the pilot commenced a go‑around. As the helicopter climbed to about 650 ft above ground level, the pilot commenced a right turn onto the downwind leg of the circuit to position for a second approach for landing. Shortly after, the pilot noticed reduced performance and decided to continue the turn back toward the airport.

The helicopter continued to lose height and, recognising that a forced landing was required, the pilot turned the helicopter left toward a school ground to attempt an autorotation landing. The helicopter subsequently collided with the rooftops of 2 houses just short of the school ground. The pilot sustained serious injuries and the helicopter was substantially damaged.

What the ATSB found

The ATSB found that as the helicopter climbed to about 650 ft above ground level, the engine lost power. The reason for the engine power loss was not determined.

The power loss was not immediately recognised which limited the opportunities for a safe forced landing. During the forced landing, the helicopter did not have sufficient height to reach the selected landing area and collided with rooftops.

Safety message

This accident highlights the challenges pilots face when confronted with a loss of engine power at low level and with few suitable landing areas available.

Pilots can best mitigate the effects of a power loss by forward planning, which reduces your mental workload under stress. The Civil Aviation Safety Authority Advisory Circular Guidelines for helicopters -suitable places to take off and land recommends:

…before conducting a take-off from any aerodrome, pilots of single-engine helicopters make themselves aware of the areas that would be suitable, from the lift-off point to a safe manoeuvring height, to conduct a forced landing in the event of engine failure after take-off.

These challenges of managing a power loss are increased for an inexperienced student pilot. While in this case, the selected landing location was unable to be reached, importantly, the pilot maintained control of the helicopter to maximise survivability.

The investigation

Figure 1: Go-around flight path of VH-OBK (Moorabbin airport)

Figure 2: Flight path of VH-OBK

Source: Google earth, annotated by the ATSB

Context

Meteorology

A meteorological report for Moorabbin Airport, recorded at 1300, included a south-westerly wind of 11 kt, visibility greater than 10 km, no cloud, a temperature of 17 °C, and a mean sea level air pressure of 1,018 hectopascals.

The estimated air pressure at 650 ft above mean sea level (600 ft AGL) was 996 hectopascals (29.4 inches Hg).[4]

Aircraft details

VH-OBK was a 3-seat Hughes Helicopters 269C helicopter, manufactured in 1980. The helicopter was powered by a 190 horsepower Textron Lycoming HIO-360-D1A, four-cylinder, fuel injected piston engine. Engine power was transmitted via a belt drive transmission to the main transmission and tail rotor drive shaft. The belt drive assembly incorporated an overrunning clutch to permit autorotation without driving the belts or engine.

The helicopter was not fitted with a low rotor RPM aural warning system, nor was it required to be.

Using information provided by the aircraft operator, the ATSB calculated that the autorotative range from 650 ft AGL was about 0.26 nm (490 m) with no wind and about 0.32 nm (590 m) with a 11 kt south-westerly tail wind.

Site and wreckage information

The helicopter impacted 2 houses  immediately adjacent to the school ground targeted for the forced landing (about 600 m from the estimated position of the power loss). The helicopter came to rest embedded in the roof of one of the houses. After recovery of the wreckage, an inspection of the helicopter’s fuel tanks found at least 60 litres of fuel on board.[5]

Figure 3: Accident site

Note: The forward section of the fuselage was cut away by first responders to facilitate removal of the pilot.

Source: Victoria Police, annotated by the ATSB

A detailed examination of the airframe or engine was not performed. However, a visual inspection of the engine cooling fan and fan shroud indicated that the engine was not running at the time of the accident. The degree of damage to the rotor blades also indicated that the engine was providing little or no power.

Witness information

Two Moorabbin air traffic controllers observed the accident. One was located within the control tower, and the other was on a break, walking about 650 m north-east of the accident site. The controller on break noted that prior to the accident, the helicopter’s descent path was shallower than that of a normal autorotation and no engine noise was heard. The controller in the tower also noted the shallow descent path.

Safety analysis

As the helicopter turned from crosswind to downwind after the go-around, the pilot recognised a reduction in performance. The pilot did not identify a change in the engine sound or vibration, however multiple radio broadcasts around this time reduced the pilot’s ability to do so. A review of the engine manifold pressure indications showed that it was significantly higher than expected and consistent with ambient conditions. Furthermore, the distance travelled during the descent was consistent with that expected for an autorotation. Both factors indicate that the engine was very likely not producing power at that time.

The shallower‑than‑expected descent profile observed by the witnesses familiar with the helicopter’s autorotative descent profile, may have been due to the beneficial effect of the pilot pitching the helicopter up to reduce the airspeed from 70‑80 kt to the target airspeed of 55 kt. After the accident, a visual inspection of the engine cooling fan and shroud identified no rotational damage, similarly indicating that the engine was not running at the time of the accident.

There were no reported actions made that may have led to the power loss and the helicopter had sufficient fuel on-board. There were no other reported indications of a fault with the engine. A detailed examination of the engine and airframe was not performed, limiting the ability to identify the reason for the power loss.

The engine power loss occurred at low height over a densely populated area presenting a challenging scenario for the inexperienced student pilot. The pilot did not immediately identify that power was lost and attempted to return to the airport while troubleshooting the reduced helicopter performance. During this time, the helicopter passed 2 suitable forced landing sites (Figure 4).

Figure 4: Flight path of VH-OBK following the engine power loss

Source: Google Earth, annotated by the ATSB

When the pilot recognised that a forced landing was required, the football oval was likely the closest suitable area, but the pilot did not identify the oval, possibly due to it being obscured by the airframe or instrument panel. The pilot identified the school ground and attempted a landing there. However, the helicopter did not have sufficient height to reach the selected site and the helicopter collided with rooftops. While the helicopter did not reach the intended area, the pilot maintained sufficient control of the helicopter and rotor RPM to conduct an autorotation landing into the rooftops, which maximised survivability.

Findings

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