What happened

On 25 February 2018, an Aeroprakt A22LS Foxbat departed a station on a flight to observe local floodwaters. At the time of departure, the dirt runway was wet and covered in part by standing water. On return from the local flight, the pilot attempted to land the aircraft on a part of the runway without standing water as close to the station as possible. The aircraft was configured with half-flap on approach and bounced on landing while negotiating the short length. Before applying power to go around, the aircraft impacted heavily on the nosewheel. The aircraft climbed out and the pilot reversed the direction of landing, in order to have greater runway available without standing water when he attempted a second landing. There was no wind at the time.

On touchdown the pilot noticed that the rudder pedals were locked and little control authority was evident. During the ground roll, the aircraft began to veer to the right towards a drum marking the edge of the runway. The pilot increased power with the intention to gain height and avoid the obstacle, and then to climb away so as to ascertain the nature of the control difficulty at a safe height.

The increase in power and upwards pitching movement of the aircraft with a groundspeed below 20 kts increased slipstream^[1], torque^[2] and gyroscopic effect^[3] at a critical phase of flight. The resultant forces rolled the aircraft to the left which could not be corrected with control input before the left wing contacted the ground. The right main undercarriage subsequently impacted a large rock, causing the aircraft to ground loop^[4] and to sustain substantial structural damage (Figure 1)

The pilot sustained minor injuries including bruising and neck pain but was unable to seek immediate medical attention due to the station being isolated by floodwaters.

Figure 1: A22LS Foxbat post-impact

Initial post-flight investigation revealed a suspected cause: a soft water bottle, previously unrestrained on the passenger seat, had lodged under the rudder pedals on the passenger side and hidden from view. Further inspection by the owner the next day revealed that the soft water bottle could not have been the cause. The bottle was trial-fitted under the rudder pedals and rudder movement was established. The pilot reported that the water bottle had most likely lodged under the pedals during the resultant accident sequence.

The pilot identified that the most likely cause of the rudder control difficulty may have come from damage sustained to the nosewheel on the first landing. The A22LS Foxbat has rudder pedal controls that are linked by a series of connecting rods to the nosewheel in order to provide easy steerage on the ground. Damage to the nosewheel assembly may have restricted rudder control input during the second landing.

Safety message

Pilots are reminded that operations from unprepared runways can be hazardous. Particular care should be given to ensure sufficient take-off and landing distance is available to effect safe operation without distraction, especially when hazards exist.

Understanding the low-speed reaction of a particular aircraft in go-around situations is also of particular importance. Safe buffers between take-off safety speed^[5] and rotation for take-off should be maintained in all normal and emergency situations. Accepting a low consequence runway excursion may be preferable to a high consequence loss of control and collision with terrain event.

Pilots and passengers are reminded of the hazard of loose objects in the cockpit, before or during flight. Not only can loose objects distract pilots during critical phases of flight, but they may also lodge in control systems, physically impact pilots and passengers, or create a fire hazard if inappropriately stored.

Pilots should routinely assess environmental and other possible external hazards prior to flight in order to fully understand the risks that may be encountered during the operation.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

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1. Spiralling airflow from the propeller that strikes the side of the vertical fin, most pronounced at high power settings.
2. Rotational reaction opposite to the direction of rotation of the propeller, most pronounced at high power settings.
3. Rotational reaction acting in the yaw axis during a pitch change, due to rotation of the propeller.
4. The aircraft enters a rapid rotation on the ground and spins until it comes to rest.
5. A speed which provides adequate control of the aircraft for flight, normally greater than 1.2 times the aircraft stall speed.

What happened

On 19 March 2018, at 1340 Eastern Daylight-saving Time (EDT), a Bell Helicopter 206L conducting an aerial weed survey struck an 11 kV powerline.

On board the helicopter was a pilot and three passengers. The scope of work was to track small creeks and rivers in search of noxious weeds. The pilot met the passengers earlier that day at a local airport. Prior to the flight, the crew conducted a job hazard analysis and discussed proposed routes for identification of anticipated hazards. The pilot also gave a detailed passenger brief. During the brief, one passenger was instructed to assist the pilot in identifying hazards such as wires.

Approximately 2 hours 10 minutes into the second flight of the day, at a height of 200 ft, the aircraft struck an unknown and unseen 11 kV powerline. The powerline had a span of 650 m. In addition to the long bay length, trees on one side and a building on the other obscured the poles from sight. The span also ran perpendicular to the main flow of powerlines that ran along the valley.

The powerline was severed by the aircraft’s wire strike protection system (WSPS). The pilot announced the emergency to the passengers and immediately landed the helicopter in a paddock below. The time frame of the incident prevented the pilot from making an external emergency transmission.

Upon landing, the pilot assessed the passengers and found that one had sustained minor injuries. The pilot and one of the passengers walked to a nearby farmhouse, called emergency services and reported the event to the aircraft operator. Emergency services attended the scene 50 minutes later.

Figure 1: Close up of WSPS showing witness marks from wirestrike

Source: Operator

Safety message

It is near impossible for the human eye to detect a thin wire at the distance needed to avoid it in flight. For this reason, pilots often depend on sighting and reading the poles and hardware over which the wire is strung. There are also limits to the field of view of the human eye, meaning a constant scan is required to identify poles. A bay length of 650 m with obscured poles leaves scarce opportunity to identify the hazard.

In aerial survey and spotting work, a pilot must make a trade-off between flying as high as possible to avoid hazards and flying low enough to allow the observers the best opportunity to successfully identify targets. Survey flight will often be below 500 ft. Because wires are so difficult to detect, their presence must be assumed at all times. All helicopter pilots are encouraged to attend a course in wire hazards; these courses teach techniques such as self-briefing, “I can’t see the wires yet” to help maintain a mindset of precaution.

The WSPS served a vital function in protecting the aircraft following the wirestrike. Though effectiveness requires contacting the wire at a suitable angle and airspeed which may not be the case in all low-level work, WSPS should be considered essential equipment in operations below 500 ft.

The pilot was able to land the helicopter immediately in an open paddock, delivering the helicopter to a safe place. When flying at low level, choosing a flight path to maximise availability of suitable forced landing areas is another vital element of protection should the aircraft experience an adverse incident.

ATSB Report Wire-strike Accidents in General Aviation: Data Analysis 1994 to 2004 and the ATSB’s booklet Avoidable Accidents No. 2 - Wirestrikes involving known wires: A manageable aerial agriculture hazard provide further information and guidance.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

What happened

On 4 March 2018, a Bombardier DHC-8 (DHC-8) departed Mildura Airport, Victoria (Vic.), for Melbourne Airport, Vic. During climb, the flight crew requested clearance to climb to FL 250^[1] and were approved by ATC to climb to FL 240.

A Boeing 737 (737) was en route from Adelaide Airport, South Australia (SA), to Sydney Airport, New South Wales (NSW), maintaining FL 250 on a crossing track.

At 1744 Eastern Standard Time (EST), ATC cleared the DHC-8 to climb from FL 240 to FL 250 resulting in a loss of separation with the 737. ATC subsequently received a short-term conflict alert (STCA). ATC instructed the crew of the DHC-8 to maintain FL 240 but as the DHC-8 was already climbing through FL 245, ATC instructed the crew to descend and turn left onto heading 090. They then instructed the crew of the 737 to turn right immediately onto heading 180 for separation. Once the separation standard was regained, the DHC-8 was cleared to climb to FL 250 and both aircraft continued without incident.

Separation reduced to 900 ft between the aircraft when they were 5 NM apart. Neither flight crew received a TCAS resolution alert (RA).

Safety message

This incident shows the effectiveness of the ATC short term conflict alert (STCA) system and conflict resolution training received by ATC for loss of separation events. It also highlights the importance of flight crews responding immediately to ATC instructions.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

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1. Flight level: at altitudes above 10,000 ft in Australia, an aircraft’s height above mean sea level is referred to as a flight level (FL). FL 250 equates to 25,000 ft.

What happened

On 23 February 2018, at about 0933 Western Standard Time (WST), a Piper Aircraft Corp PA-44-180 was conducting a training flight from Jandakot Airport, Western Australia (WA) to Rottnest Island Airport, WA with two crew members on board.

During the approach to Rottnest Island, the landing gear was extended. The gear unsafe light illuminated during the extension process and turned off when the left and nose gear lights turned green to indicate they were locked, however, the right gear light did not illuminate. The crew conducted a missed approach and began to troubleshoot the issue during the return flight to Jandakot.

On approach to Jandakot, the crew followed the emergency gear extension procedure. The light for the right-hand gear did not illuminate to indicate the landing gear had locked, however the gear unsafe light remained off.

The crew requested a fly-by of the tower for a visual inspection of the landing gear. Air Traffic Control (ATC) reported that all three wheels appeared down, with no differences between left and right observed.

The crew requested emergency services to be on standby and once confirmed, made their final approach. On landing, the right landing gear collapsed, and the aircraft came to a stop to the right of the runway, at 90 degrees. ATC activated the crash alarm and full emergency procedures were conducted. The crew disembarked the aircraft unharmed.

Engineering inspection

Following the incident, inspection of the right-hand landing gear revealed that the gear actuator seals were not correctly functioning and that the pivots on the down lock mechanism were stiff. The faulty seals resulted in a loss of actuator pressure in the down position. When emergency procedures were followed for gear extension, the gear could not free fall and lock into position due to the resistance at the pivot. It was noted that retraction and free fall of the landing gear was tested during maintenance in November 2017 with no non-normal indications. However, the aircraft was not returned to service until February 2018, during which time it is suspected that the pivots became stiff.

Repairs to the aircraft were carried out in accordance with the aircraft maintenance manual to:

• reseal the actuator with new O-rings
• replace the down lock springs
• dismantle, grease and reassemble the down locks.

Testing of the landing gear was conducted, and the aircraft was returned to service.

Safety message

Where an aircraft has been out of service for an extended period of time, it is important to verify the functionality of all critical aircraft components before returning it to service. These checks should be conducted in addition to the routine, pre-flight checks.

It is important that pilots remain aware that despite conducting comprehensive pre-flight checks, unanticipated failures can still occur during flight. In this situation, the flight crew took all possible precautions prior to landing by:

• following non-normal procedures
• conducting additional checks to assess the situation
• providing clear communications to ATC.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

What happened

On 30 January 2018, a Bell 206B helicopter departed Sunshine Coast Airport, Queensland (Qld), to conduct a navigational training flight. The crew consisted of an instructor and a student.

At approximately 1500 Eastern Standard Time (EST), on the final leg of the flight, the crew heard a noise followed by a high frequency vibration. The instructor elected to conduct a precautionary landing. At approximately 200 – 300 ft above ground level (AGL), the engine chip detector^[1] light illuminated on the warning panel. Due to the low altitude, the instructor elected to land with power on and conducted an emergency engine shut down after landing.

As the crew shut down the engine, smoke was identified emanating from the right side of the engine area and the crew subsequently observed a large quantity of oil was identified in this area.

Maintenance engineers identified a number one bearing failure of the engine compressor assembly.

Safety message

Simulated total loss of power and a subsequent practice forced landing is at the core of a pilot’s emergency training. This incident highlights the importance of flight crews maintaining awareness of all system states and being prepared to act at the first sign of trouble. Unusual noises and vibrations during flight have the potential to rapidly propagate unless it is quickly identified and managed, and the aircraft landed at the earliest opportunity.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

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1. Chip detector: a magnetic device used to gather chips of metal from engine or transmission oil to provide early warning to maintenance personnel of impending engine failure. Depending on the installation, it can be linked to an in-cockpit indicating light to provide immediate advice to aircrew.

What happened

On 5 February 2018, a Boeing 717-200 was being prepared for a commercial passenger flight from Melbourne, Victoria (Vic.), to Hobart, Tasmania (Tas.). This was the third and final sector for this crew on the day. As the flight crew were programming the standard instrument departure (SID) into the flight management system (FMS), an incorrect runway was selected.

Air traffic control cleared the aircraft to take-off between two aircraft which arrived in close succession. During the initial climb, the flight crew identified the error before any deviations from the SID occurred. The flight crew manually selected the track required by the SID on the auto flight system. The flight crew subsequently corrected the error in the secondary flight plan and selected this plan as the primary plan in the FMS.

During the cruise, the performance figures for both runways were compared. It was determined that a longer runway was used for take-off than had been selected in the flight management system so there was no additional risk of a runway overrun.

Safety message

This incident highlights the importance of ensuring that the flight management system is programmed correctly for take-off. Ensuring that independent cross-checks are undertaken can reduce the risk that an aircraft attempts to take-off with incorrect performance data. Further information is available from the ATSB research report AR-2009-052, Take-off performance calculation and entry errors: A global perspective.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

What happened

On 18 January 2018, the pilot of a Raytheon Hawker 850XP was conducting a check and training exercise from Bundaberg, Queensland (Qld) with three crew on board.

The aircraft arrived at Gladstone airport, Qld at about 1140 Eastern Standard Time (EST). Part of the exercise involved the practice of a one engine inoperative approach and landing in which the pilot inadvertently applied the right hand (RH) brakes causing both RH tyres to lock up and the anti-skid to cease functioning. The aircraft came to a stop and the pilot slowly taxied the aircraft clear of the runway. The anti-skid on this aeroplane does not have locked wheel protection.

The post-flight inspection revealed both RH main landing gear tyres deflated.

Safety action

As a result of this incident, the operator advises that the pilot was debriefed and has since completed simulator training in the Hawker recurrent simulator.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

What happened

On 7 March 2018, at about 2018 Eastern Daylight-saving Time (EDT), a Fairchild SA-227-DC arrived at Essendon airport and taxied clear of the runway. During taxi, the flight crew noticed a smell and observed a smoke haze about halfway down the cabin. The aircraft was shut down and the crew and passengers evacuated the aircraft safely. Fire services were not required. Following exterior safety checks, the aircraft was towed to maintenance for investigation.

Following investigation of the aircraft’s air-conditioning system, it was discovered that the left cooling turbine was seized and unable to be rotated. Evidence of metal fragments were also found around the cooling turbine body. Significant damage to the turbine impeller was also observed due to contact within the cooling turbine housing (Figure 1).

Figure 1: Left cooling turbine impeller damage

Source: Aircraft operator annotated by ATSB

Safety message

Smoke and fumes can originate from any number of aircraft systems during any stage of aircraft operation. This incident highlights the effective flight crew management of maintaining awareness at all times and carrying out the actions required to ensure the situation was handled effectively, including the evacuation of the aircraft.

The joint CASA and ATSB research report AR-2013-213, An analysis of fumes and smoke events in Australian aviation, found that a majority of smoke and fumes events were minor in consequence and that they were generally managed appropriately by the flight crews.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

What happened

On 30 March 2018, at about 1420 Eastern Daylight-saving Time (EDT), a SAAB 340B was en-route to Moruya, New South Wales (NSW), with three crew members and 10 passengers on board. During final approach, the pilot monitoring^[1] (PM) selected gear down. Immediately following, the crew received a hydraulic system caution indication. The “Hydraulic Light ON” requires the action of “Memory Items” and then the conduct of the “Abnormal Checklist”.

While conducting a holding pattern above Moruya airport, the flight crew carried out failure management procedures. The crew verified that the nose gear was down and locked but did not receive a down and locked indication for the main gear. The crew contacted operations to confirm the manufacturer’s recommended speeds for gear-down flight, and landing distance calculations for a zero-flap landing in Sydney. In consultation with the company emergency response team, they made the decision to divert the aircraft to this airport.

The PM declared a PAN PAN^[2] and advised air traffic control (ATC) that the aircraft required a landing on runway 16 at Sydney due to the crosswind on runway 07 and a long final approach. In addition, the crew advised that the aircraft would need to be shut down on the runway prior to being towed to the parking bay. The flight attendant was advised of the need for a precautionary cabin preparation.

On descent into Sydney, the flight crew extended the landing gear with the hand pump extension and received a down and locked indication. The flight crew subsequently obtained a clearance for a long final to ensure a stable approach, and completed a flapless landing. The aircraft was brought safely to a stop on the runway where it was shut down in accordance with standard operating procedures for a hydraulic malfunction and then towed to the bay.

Following the incident, engineering fault isolation identified a faulty relay in the hydraulic system. The relay was replaced in accordance with the aircraft maintenance manual, functional checks were carried out and the aircraft was returned to service.

Safety message

This incident highlights the importance of having experienced flight operations and engineering support staff to assist well-trained flight crew with making decisions in the event of a technical failure in-flight. Clear communication with ATC also resulted in a safe outcome.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

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1. Pilot Flying (PF) and Pilot Monitoring (PM): procedurally assigned roles with specifically assigned duties at specific stages of a flight. The PF does most of the flying, except in defined circumstances; such as planning for descent, approach and landing. The PM carries out support duties and monitors the PF’s actions and the aircraft’s flight path.
2. PAN PAN: an internationally recognised radio call announcing an urgency condition which concerns the safety of an aircraft or its occupants but where the flight crew does not require immediate assistance.

What happened

On 1 March 2018, at about 0730 Eastern Daylight-saving Time (EDT), the flight crew of a Bombardier DHC-8-402 aircraft reported to engineering staff at Sydney, New South Wales (NSW), that a torch was missing from the flight deck. The engineering staff subsequently inspected the flight deck and found the torch behind the left-side rudder pedals. It was unknown as to how or when the torch moved from its usual position.

Safety message

This incident highlights the importance of not only ensuring unaccounted items are located, but loose items are secured to prevent interference with the aircraft’s controls.

ATSB investigation report AO-2017-108 (Foreign object damage involving Airbus A320) notes that the presence of foreign object debris poses a significant threat to aircraft safety and demonstrates the effect that foreign object debris can have on aircraft operations. Similarly, the National Aeronautics and Space Administration aviation safety reporting system provided an example of where a foreign object jammed the rudder pedals during a critical phase of flight (aviation safety reporting system report number 736444). While taking off, the left rudder pedal became jammed on a Regional Jet CRJ700 aircraft and the take-off was successfully rejected. The pilot reported that directional control was difficult, but maintained during the rejected take-off. The pilot subsequently found a small tissue box under the rudder pedal.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.