Investigation summary

What happened

On 15 January 2025, the pilot of a Piper PA-28-181 aircraft was conducting a flight between Bankstown Airport and Orange Airport, New South Wales, under visual flight rules (VFR). The pilot held a Private Pilot Licence (Aeroplane) (PPL‑A) and was conducting a solo flight to gain command flight experience required to obtain a Commercial Pilot Licence (Aeroplane). Although the pilot held a PPL‑A, they were required to obtain a flight authorisation from a supervising instructor, as a condition of hiring the aircraft from the operator, Basair. 

The weather at Bankstown Airport at the time of departure was below the visual meteorological conditions (VMC) required for flight under VFR. However, prior to departure the pilot and authorising instructor did not review the local weather observations or otherwise identify that the weather was not suitable for a VFR flight. 

Although the pilot was subsequently advised by the Bankstown Tower air traffic controller that the zone was not VMC, they decided to depart Bankstown Airport under a special VFR clearance, which is a clearance that allowed for flight in reduced visibility and distance to cloud than normal VFR while operating in controlled airspace. However, soon after take-off, the aircraft entered adverse weather conditions, which were presented on the local weather observations. While manoeuvring to avoid cloud, the pilot attempted to fly between a gap in the clouds. The gap closed and the aircraft inadvertently entered cloud.

After completing a 180° turn, in an attempt to return to VMC, the aircraft remained in cloud. The pilot then contacted the Bankstown Tower and advised them of the situation. The Bankstown Tower controller provided traffic information about a nearby instrument flight rules (IFR) aircraft to the pilot, along with further navigation assistance to regain visual flight conditions.

The aircraft then returned to Bankstown with no damage and the pilot was uninjured. 

What the ATSB found

The ATSB found that the pilot’s decision to depart was probably influenced by self‑imposed internal pressure to complete the flight, which resulted in them requesting a departure from Bankstown Airport under special VFR. This decision resulted in the pilot finding themselves in adverse weather conditions and unable to maintain VMC. The aircraft subsequently entered cloud, increasing the risk of:

• spatial disorientation
• collision with terrain while operating below the lowest safe altitude
• collision with an aircraft operating under the instrument flight rules.

The ATSB also identified that the instrument training the pilot received to escape inadvertent entry to cloud assisted in their safe return to visual conditions.

What has been done as a result

At the time of writing Basair was implementing changes to its processes regarding when students may request special VFR prior to departure, and how such requests were reviewed and approved by instructors.

Safety message

Between the beginning of 2020 and end of 2025, the ATSB recorded 57 occurrences of VFR aircraft entering instrument meteorological conditions (IMC), resulting in 8 fatal accidents and 17 people fatally injured. Early assessment of weather conditions combined with early decisions to land at suitable nearby airports or to delay/not depart, are still the best way to prevent VFR pilots flying into IMC. Forecasts are only an expectation of the weather. Where possible, pilots should utilise local and current observations of the weather conditions to determine if the conditions are suitable. Tools such as the Civil Aviation Safety Authority’s Flight planning - Standing personal minimums checklist can also be helpful for determining if the conditions are suitable for your experience level. Navigating the margins with Special VFR | Flight Safety Australia, may assist pilots in their decision‑making regarding when it is appropriate to use special VFR.

If a pilot inadvertently enters IMC, they should fly the aircraft first with reference to instruments and inform air traffic control. Additionally, if an autopilot is fitted to the aircraft, it can be a valuable tool to assist a pilot who is competently trained in its use.

The occurrence

On the morning of 15 January 2025, the pilot of a Piper PA-28-181 aircraft, registered VH‑BTN (BTN) planned to conduct a flight between Bankstown Airport and Orange Airport, New South Wales, under the visual flight rules (VFR).[1] The pilot held a Private Pilot Licence (Aeroplane) (PPL‑A) and the aircraft was hired from Basair to support the development of cross-country command capability and decision-making experience required for the issue of a Commercial Pilot Licence (Aeroplane).

Pre-flight preparation

After arriving at Bankstown Airport at 0604 local time, the pilot obtained weather information from Airservices Australia and completed their pre‑flight planning. At 0700, the pilot attended a scheduled authorisation briefing with an instructor, along with 3 other pilots. Although the pilot held a PPL‑A, due to their low level of command experience, the operator required an instructor to authorise the flight.

During the authorisation briefing, the instructor reviewed the weather with all 4 students and discussed the threat posed by low cloud forecast near the Blue Mountains and the possibility of not being able to complete the flight. At the conclusion of the briefing, only the occurrence pilot was assessed as having completed the required planning and preparation to be authorised. In interview with the ATSB, the instructor stated they reviewed the visual meteorological conditions[2] (VMC) criteria with the students and explained that they should return to Bankstown if VMC could not be maintained.

The Bankstown Airport forecast obtained by the incident pilot at 0604 indicated that the weather would not be suitable for departure from Bankstown due to low cloud. However, the amended forecast for Bankstown Airport, issued at 0650, indicated that the low cloud layer would lift at 0800, making a VMC departure possible. Both the supervising instructor and occurrence pilot reviewed this forecast, however the current weather observations and automated terminal information service[3] (ATIS) information were not considered during the briefing.

At the end of the authorisation briefing, the instructor signed the command flight record, which approved the pilot to conduct the occurrence flight.

The flight

Prior to taxiing, the pilot accessed the ATIS that reported the presence of overcast[4] cloud at 1,000 ft above ground level. At 0832, the pilot requested and obtained taxi clearance, and taxied as instructed by the Bankstown Ground controller to runway 29R.[5] At 0840 the following communication exchange occurred:

0840:42 BTN: ‘Bankstown Tower, Archer Bravo Tango November at holding point alpha 8, 29R ready for an upwind departure’

0840:47 Bankstown Tower: ‘Bravo Tango November the zone is not VMC, advise’

0840:53 BTN: ‘Bravo Tango November request special VFR’

At 0843 the pilot was cleared for take-off and departure under special VFR (see the section titled Visual flight rules). At 0846 the pilot communicated to Bankstown Tower that they were leaving the Bankstown airspace. At approximately 0848, flying at 1,500 ft above mean sea level (AMSL), the pilot made a left turn to fly between a gap in the clouds. As they passed through the gap, the gap closed and visual reference of both the horizon and ground were lost.

Finding themselves in cloud, the pilot did as they had been previously trained for such circumstances and focused on their instruments to conduct a 180° turn in an attempt to return to visual conditions. However, the turn completed by the pilot exceeded 180° and the aircraft did not return to VMC (Figure 1). The pilot later reported to the ATSB that, while operating in cloud, they believed the aircraft was in a safe position and under control thanks to their training. 

However, while still in cloud, the pilot became alarmed about a potential collision risk with other aircraft when they recognised on their GPS that they were near Prospect Reservoir, a Bankstown Airport inbound reporting point. 

Figure 1: VH-BTN flight path

Source: Flight Radar 24 flight data on Google Earth, annotated by the ATSB

At 0850, the pilot advised the Bankstown Tower controller that they were in IMC just outside the controlled area. At this time, the controller advised the pilot of an instrument flight rules (IFR)[6] aircraft that had departed Bankstown and was 1.5 NM (2.8 km) east of their position, tracking west bound and climbing through their altitude. The pilot of VH‑BTN replied that they were unable to see anything.

VH-BTN entered cloud at approximately 1,500 ft AMSL in an area where the lowest safe altitude was 2,500 ft AMSL (see the section titled Lowest safe altitudes). Once traffic separation was assured, the Bankstown Tower controller advised the pilot to climb above the cloud and the lowest safe altitude. The pilot responded they were climbing above the cloud and, a short time later, the controller suggested the pilot should climb to 2,500 ft. At 0851 the pilot reported that they were now above the cloud. The tower controller provided the pilot with suggested tracking to return to Bankstown and advised that there was a gap in the cloud over the airport sufficient to descend through.

The pilot returned to the airport, landing shortly after 0858.

Context

Pilot information

Pilot in command

The pilot in command held a Private Pilot Licence (Aeroplane) (PPL-A) issued on 15 October 2024[7] and a class 1 aviation medical certificate valid until 8 October 2025. They had a total flight experience of 92 hours, of which 86.2 hours were obtained on PA‑28 type aircraft. 

The pilot reported they had approximately 25 hours experience as pilot in command of an aircraft. The pilot had also accrued 6.7 hours of instrument flight experience.

In a post-occurrence survey completed by the pilot in command, they described that at the time of the occurrence, their fatigue level was ‘very lively and responsive, but not at their peak’.

Supervising instructor

The supervising instructor held a Commercial Pilot Licence (Aeroplane) (CPL-A) issued on 5 July 2021 and a class 1 aviation medical valid until 13 May 2025. Their grade 2 instructor rating was issued on 3 April 2024.

On the day of the incident, the supervising instructor’s schedule was to conduct flight authorisations from 0700–0800 and then attend a staff meeting from 0800–0830.

Aircraft information

The aircraft was a Piper PA-28-181, which was manufactured in 2003 in the United States of America and issued serial number 2843564. It was first placed on the Australian register in March 2017. 

The aircraft was powered by a Lycoming O-360-A4M engine driving a 2‑bladed Sensenich propeller. It was certified for instrument flight rules (IFR) flight and was equipped with 2 Garmin 430 GPSs and an S-Tec autopilot system. According to the aircraft maintenance release, all systems were serviceable at the time of the incident.

Airspace

Australia’s airspace is broken into different classes, which have different operating rules (Figure 2). The 2 classes relevant to this incident are Class D and Class G.

Class D airspace is often used at high-density traffic airports, which have a control tower, and is mostly used by general aviation aircraft. It requires pilots to obtain a clearance from an air traffic controller to arrive and depart the airport. Bankstown Airport was a metropolitan Class D airport.

Class G airspace is the areas that are not otherwise classified. It does not require a clearance and is non-controlled. Pilots are responsible for their own separation from other aircraft in this airspace.

Figure 2: Australian airspace structure

Source: Airservices Australia

Bankstown Airport

When active, Bankstown Tower provided Air Traffic Services in the Class D airspace surrounding Bankstown Airport. The Class D airspace extended from the ground to 1,500 ft.

Bankstown Airport had 3 runways in the 29 direction. They were designated 29L, 29C, and 29R. When the 29 runways were in use, the local traffic regulations required departing aircraft to climb and maintain 1,000 ft AMSL until leaving the controlled airspace. This required a minimum cloud height of 1,500 ft to comply with Class D airspace visual meteorological conditions (VMC) during departure (see the section titled Visual flight rules).

Aircraft leaving Class D airspace in a westerly direction at 1,000 ft AMSL enter Class G airspace.

Lowest safe altitudes

To ensure safe flight under IFR or VFR at night, pilots who have received training for these flight activities will be aware of the requirement to calculate and comply with lowest safe altitude (LSALT) requirements. LSALT is the lowest altitude that will provide safe terrain clearance at a given place. 

There are multiple ways of determining the LSALT in a specific area. It can be extracted from maps, an airport’s departure and approach procedure plate, manually calculated, or ATC can provide assistance to pilots in determining a safe altitude.

The expectation is that VFR pilots will continually see and avoid terrain. Therefore, they are not required to calculate the LSALT prior to flight. The lowest available LSALT for the area within 15 NM (28 km) of Bankstown Airport was 2,500 ft. 

The pilot was unaware of the LSALT in the area where they entered IMC.

Meteorological information

The operator provided the ATSB with scanned copies of the pilot’s flight planning materials. This included the meteorological information they used to plan their flight.

The Bureau of Meteorology provided weather forecasts and observations for the day of the incident. The Bankstown Airport terminal aerodrome forecast (TAF) issued at 0604 forecast variable winds at 3 kt, flight visibility of 10 km and broken[8] cloud at 800 ft above the airport elevation. The TAF did not forecast an improvement of cloud conditions to meet the VMC requirements until 1300 (see the section titled Visual flight rules).

A SPECI[9] for Bankstown Airport issued at 0600 included overcast cloud at 1,100 ft recorded by the automatic weather station, consistent with the forecast low cloud on the TAF. Significantly, the cloud base and extent in this observation were below that required for a standard VMC departure in Class D airspace:

SPECI YSBK 141900Z AUTO 13003KT 9999 // OVC011 23/21 Q1003 RMK RF00.0/000.0

An amendment to the Bankstown TAF was issued at 0650. The forecast at that time showed broken cloud at 1,300 ft and improving from 0800 to scattered cloud at 1,500 ft:

TAF AMD YSBK 141950Z 14119/1512
VRB03KT 9999 BKN013
FM142100 VRB03KT 9999 SCT015…

Additionally, Airservices Australia provided the ATSB with the Bankstown Airport automatic terminal information service (ATIS) from 0830, designated information ‘Delta’. 

Information Delta stated:

• overcast cloud was present at 1,000 ft
• runway 29 right, centre, and left were in use
• arriving aircraft should expect an instrument approach. 

VH-BTN called for taxi clearance at 0832 advising air traffic control (ATC) they had received information ‘Delta’.

The automated SPECIs for Bankstown Airport between 0700 and 0900 all showed overcast cloud at 1,100 ft.

While the amended TAF issued at 0650 indicated the weather was improving and would be suitable for a VMC departure, the actual observations from Bankstown Airport at the departure time showed that weather conditions did not support a departure without the use of special VFR. 

Specifically, at 0830 (13 minutes prior to take-off), the airport observation recorded the cloud as overcast at 1,100 ft. The subsequent Bankstown Airport weather observations recorded that the cloud base lifted and reduced in sky coverage from 0900 (28 minutes after the original taxi time) – broken cloud was at 1,300 ft. At 0930 the observation recorded broken cloud at 1,500 ft.

The supervising instructor stated that their briefing highlighted the threat presented by low cloud forecast over the Blue Mountains. To mitigate the risk of students flying into IMC, the supervising instructor quizzed them on the VMC requirements in Class G airspace (see the section titled Visual flight rules).

The supervising instructor also stated that from the time of the student’s booking, the weather was supposed to improve to scattered cloud at 1,500 ft. 

The supervising instructor did not consider the actual weather observations in the vicinity of the airport at the time of departure. Instead, they reviewed the expected conditions based on the weather forecast. Neither the pilot nor the supervising instructor recalled discussing delaying the departure. While the pilot did listen to the ATIS prior to taxi, at that time, they had already received the required flight authorisation.

Visual flight rules

The flight was planned to operate under the visual flight rules (VFR), which required the pilot to continuously maintain VMC. The Civil Aviation Safety Authority’s (CASA) Civil Aviation Safety Regulations 1998 stated:

91.280 VFR flight–compliance with VMC criteria

(1) The pilot in command of an aircraft for a VFR flight contravenes this subregulation if, during the flight, the aircraft is not flown in accordance with a requirement of the VMC criteria for the aircraft and the airspace in which the flight is conducted.

(2) Subregulation (1) does not apply to a flight of an aircraft if:

(a) air traffic control has authorised the pilot in command of the aircraft to conduct the flight under the special VFR; and

(b) the pilot in command complies with the special VFR.

The requirements for VMC differed depending on the airspace and altitude at which the aircraft operated.

Class D

The conditions required to maintain VMC in class D airspace were:

• minimum flight visibility 5,000 m
• minimum distance from cloud
  • 600 m horizontal
  • 1,000 ft vertically above cloud
  • 500 ft vertically below cloud

Class G

The conditions required to maintain VMC in class G airspace below 3,000 ft AMSL or below 1,000 ft above ground level (whichever was higher) were:

• minimum flight visibility 5,000 m
• remain clear of cloud
• maintain sight of ground or water

Special VFR

The CASA visual flight rules guide stated:

By day, when VMC do not exist, the ATC unit responsible for a control zone (CTR) or control area (CTA), at your request may issue a ‘special VFR clearance’ for flight in the CTR, or in a CTA next to the CTR, for the purpose of entering or leaving the CTR, providing an IFR flight will not be unduly delayed.

The conditions required to maintain VMC while operating with a special VFR authorisation were:

• minimum flight visibility 1,600 m
• remain clear of cloud.

The CASA flight safety publication Navigating the margins with special VFR stated that it is most often requested under the following circumstances:

• departures, where the pilot can see a path to VMC outside controlled airspace

• arrivals, when weather at the aerodrome is marginal but the pilot is visual

• transits, particularly in coastal areas prone to mist or patchy fog.

Additionally, CASA highlights the risks involved when flying under the special VFR:

• choosing special VFR due to less-than-VMC cloud conditions means reducing the margin for error, often bringing you closer to terrain and risking inadvertent IMC

• if visibility is the issue, you’ll be reducing your forward visual window, requiring intense concentration, greater situational awareness and rapid decision-making

• even after receiving a Special VFR clearance to depart controlled airspace, you will need to ensure you can meet normal VMC criteria as soon as you leave that airspace, and the clearance no longer applies.

The publication provides the following warning to pilots:

But Special VFR is not a workaround for poor planning or an excuse to press on. It’s a tool to be used deliberately and sparingly, and with careful consideration. If better options exist – such as diverting, delaying or requesting IFR clearance – they’re often safer.

The authorising instructor stated that they did not anticipate the pilot’s use of special VFR and did not expect they would be able to depart Bankstown Airport if the airport conditions were not VMC.

During interview with the ATSB, the pilot stated that they heard other aircraft in the area requesting special VFR and, while not fully understanding what they were requesting, they believed it would facilitate their departure. They also believed that the weather conditions would be suitable for the navigation exercise if they could depart the Bankstown Airport controlled airspace.

VFR into IMC

Between 2016 and 2025 (inclusive), the ATSB occurrence database recorded 105 occurrences of VFR aircraft entering IMC conditions. About 1 in 10 of these occurrences resulted in a fatal outcome.

Sensory illusions and spatial disorientation

One of the dangers associated with VFR into IMC is that, without a visual reference such as the horizon, pilots who have not received specialised training are vulnerable to sensory illusions and often become spatially disoriented.

The ATSB’s Accidents involving Visual Flight Rules pilots in Instrument Meteorological Conditions (2019) stated:

…for a non-instrument rated pilot, even with basic attitude instrument flying proficiency, maintaining control of an aircraft in IMC by reference to the primary flight instruments alone entails a very high workload that can result in narrowing of attention and loss of situational awareness.

The CASA AvSafety publication Spatial disorientation (CASA) stated:

Flying into poor weather without the right training and experience can rapidly lead to spatial disorientation which is a potentially dangerous anatomical reaction to an unnatural situation.

This publication describes various somatogyral[10] and somatogravic[11] illusions that may be experienced by pilots who find themselves in IMC. These illusions result from a human body’s misinterpretation of what is occurring, and often lead to spiral dives, spins, and aerodynamic stalls. Occurrence of these illusions increase the risk of a fatal accident occurring.

Recovery from inadvertent entry to IMC

Industry guidance 

CASA provided multiple resources for assisting VFR pilots with preventing inadvertent entry to IMC. 

The AvSafety Flying into bad weather (CASA) publication stated:

Flying into bad weather without the right training and experience can rapidly lead to spatial disorientation.

It provided multiple points of advice to pilots which included:

• Maintain control – fly the aircraft first.

• Make decisions early. When in doubt, turn about, divert or hold in an area of good weather.

• Make a 180-degree rate 1 turn – establish on instruments early. 

• If you need assistance, ask ATC. They are there to help you.

Additionally, CASA’s Visual flight rules guide stated:

The dangers of VFR pilots flying into IMC have been recognised for a very long time, yet they still fly into deteriorating weather and IMC. 

Pilot decision-making, particularly regarding weather and flight, is often complex; however, the solution to avoiding VFR into IMC when weather is marginal before take-off is not to depart. During flight, it is to turn back or divert before it becomes impossible to do so.

Accidental flight into cloud can be prevented by always ensuring you have a defined horizon above the terrain and below the cloud and, when this is not the case, deciding early to turn back or divert.

The CASA Flight Safety article Caught in the clouds (2024) recognised the dangers of high workload and spatial disorientation attributed to VFR into IMC occurrences and advised using modern equipment to assist pilots, where they are adequately trained.

Another way to fly out of cloud is to use the aircraft’s systems. Modern GPS equipment often includes basic variations of ground proximity (GPWS) and terrain awareness warning systems (TAWS). Although individual commercial brands are largely unregulated, they can still offer some degree of obstacle awareness in the absence of any visual references. Before using uncertified GPWS/TAWS, check you are adequately trained to use them properly.

The Federal Aviation Administration (FAA) safety publication Fly the aircraft first (FAA, 2018) highlighted the well-known slogan ‘aviate, navigate, communicate’. This is a simple way of prioritising the fundamental tasks that a pilot must complete. The highest priority is flying the aircraft and managing the flight path. Then the pilot needs to determine where they are and where they are going. Finally, the pilot should communicate their intentions to other traffic and/or ATC. 

Regulations regarding Instrument flight training

The CASA Civil Aviation Safety Regulations 1998 Part 61 Flight crew licencing stated the following instrument flight experience requirements for the issue of the relevant licence:

• 61.525 Aeronautical experience requirements for grant of private pilot licences—aeroplane category… 
  (e) at least 2 hours of dual instrument time; and 
  (f) at least one hour of dual instrument flight time in an aeroplane.

• 61.590 Aeronautical experience requirements for grant of commercial pilot licences—aeroplane category… 
  (d) at least 10 hours of instrument time; and
  (e) at least 5 hours of instrument flight time in an aeroplane.

The 61.475 Requirements to grant recreational pilot licences did not state a minimum instrument flight experience requirement.

The CASA Manual of Standards Part 61 described the skills and knowledge requirements to meet the competency standards for full instrument panel manoeuvres. The following requirements were necessary to issue an RPL‑A, PPL‑A, or CPL‑A.

• IFF.1[12] – Determine and monitor the serviceability of flight instruments and instrument power sources

• IFF.2 – Perform manoeuvres using full instrument panel

• IFF.3 – Recover from upset situations and unusual attitudes

The range of variables across which these criteria are to be applied included conducting a 180° turn to re-establish visual flight, which was consistent with the operator’s training.

IFF Full instrument panel manoeuvres

3 Range of variables

(c) for RPL, PPL, CPL licence and multi-engine aeroplane class rating training and assessment, day VFR simulated inadvertent entry into IMC with a level 180° turn to re‑establish visual flight

Autopilot use

An autopilot manipulates the aircraft flight controls on behalf of the pilot, to either maintain a desired aircraft state or transition to a new desired aircraft state. A wide range of autopilot systems are fitted to General Aviation aircraft; these systems differ in capability and complexity. 

Autopilot use can reduce the pilot’s workload and susceptibility to spatial disorientation allowing a pilot to focus on scanning instruments and managing the situation.

The FAA Instrument flying handbook (FAA, 2012) stated:

The autopilot should be utilized to reduce workload, which affords the pilot more time to monitor the flight. Utilization of the autopilot also decreases the chances of entry into an unusual attitude.

Additionally, the Advanced avionics handbook (FAA, 2009) stated:

…autopilot can be extremely useful during an emergency. It can reduce pilot workload and facilitate efforts to troubleshoot the emergency.

The United Kingdom Civil Aviation Authority Civil Aviation Publication 2960 Safety Sense, VFR flight into IMC (UK CAA, 2024) stated:

When an unanticipated entry into IMC occurs, you may experience spatial disorientation. This occurs when your perception of the aircraft’s position, attitude, or motion does not align with reality. You may make control inputs based on this false perception, and experience loss of control.

If the aircraft has an autopilot, engaging it will allow you to retain control of the aircraft and free up capacity for situational awareness.

The Airservices Australia In-flight emergency response checklist (Airservices Australia, 2024), contained a checklist for ATC personnel to apply when assisting a pilot who has inadvertently entered IMC. This included the suggestion for pilots to utilise their autopilot to assist in cases of inadvertent entry to IMC. The ATC checklist stated:

Instruct pilot:

• no abrupt manoeuvres

• shallow climbs/descents/turns

• turn first, establish straight and level then climb/descend

• suggest use of autopilot if equipped and competent.

Autopilot safety concerns

Autopilots can be an extremely useful tool for pilots who are competent in their use. However, autopilots can be complex, and research has found that in some cases increasing the level of automation can result in undesired aircraft states.

The Federal Aviation Administration’s Advanced Avionics Handbook (2009) states that programming complex functions of an autopilot can increase workload. Additionally, over‑reliance on automation can reduce manual handling skills which are necessary if the system fails or it becomes safer to reduce the level of automation. 

Servo actuators commanded by the autopilot to control the aircraft can also fail and manually opposing an autopilot servo can also result in significant flight control forces. These can result in loss of control and pilots flying aircraft with such systems should be familiar with the emergency checklists associated with recovering from these events. These concerns, and others relevant to the autopilot system, should be addressed when training and assessing someone as competent.

Organisational information

The operator held a CASA-issued Air Operators Certificate with Part 141 and 142 Flight training approval. They were a registered training organisation and provided flight training across 2 locations in single and multi-engine aircraft.

Student loan

The operator provided training for the qualification AVI50222 Diploma of Aviation (Commercial Pilot Licence – Aeroplane). Students enrolled in this qualification could take advantage of the vocational education and training (VET) student loans programs.

The VET student loans program was an Australian Government initiative designed to financially support higher education students in areas of high industry need. The occurrence pilot was enrolled in the VET student loans program, which required compulsory repayment when the loan holder’s income was above the threshold.

Recency requirements

The operator’s flight training manual stated licensed pilots were not to act as pilot in command of a school aircraft unless they had complied with the company’s recency requirements (Figure 3).

Figure 3: Operator recency requirement flow chart

Source: Operator 

The pilot previously flew on 19 December 2024. As they had less than 40 command hours, their recency was set to expire on 18 January 2025, 3 days after the planned flight.

Basair informed the ATSB that if the pilot’s 30-day recency had not expired, a single take-off and landing was sufficient to reset their recency. The pilot stated that they were aware of this prior to commencing the cross-country[13] flight, however, they also believed that circuits were not available due to the prevailing weather at the time they departed Bankstown Airport.

If a flight, which included a single take-off and landing, was not completed in the 30 days, a dual check flight with an instructor was required. This flight would include circuits, abnormal procedures, arrival and departures from another aerodrome. The operator stated that the duration of this flight was expected to be 1.5 to 2.0 hours, costing approximately $910, plus any applicable aerodrome landing fees. The cost of a dual check flight required when a student did not maintain recency was not covered by the loan program.

During the post-occurrence interview with the ATSB, the pilot stated that their recency was about to expire, and they noted the financial consequence of this. They also stated that the day of the occurrence was the best forecast weather before their recency expired and that completing the flight would remove their concern about its expiration.

Solo flight authorisation

Prior to the operator approving solo flights, students, including those who held a PPL‑A, were required to complete the flight authorisation procedure and obtain authority from the supervising instructor on duty. The operator’s Authorise and conduct solo operations procedure stated:

Each student will present their documents to the supervising instructor for review. The following documents must be checked: 

• Licence, Medical, ARN[14], ELP[15] valid and appropriate for flight

• Training file stating competency for solo flight

• Maps, charts, ERSA[16] in date, covering the area of operation

• Check aircraft MR[17] suitable for operations

If there is an element that prevents the student from operating solo, the student’s flight should be cancelled.

Additionally, the supervising pilot was required to provide a threat and error management briefing. The procedure also provided the structure of this briefing:

Beginning with the base aerodrome, the supervising instructor will brief the NOTAMs[18] and associated weather. The briefing will continue with a focus to the local training area. Once the local area has been briefed, the supervising instructor will authorise the pilots conducting local operations.

The briefing will continue to include all enroute weather, airspace, terrain and aerodromes for the area of operations.

Training

Instrument flight training

The operator provided training to pilots to assist them in the case of inadvertent entry to IMC. Their Recreational Pilot Licence (Aeroplane) (RPL‑A) training lessons included basic instrument flight in a simulator and in an aircraft. Students were required to show competency in the following:

• determine and monitor the serviceability of flight instruments and instrument power sources
• perform manoeuvres using full instrument panel
• recover from upset situations and unusual attitudes

The ATSB conducted interviews with the pilot in command and the supervising instructor. The pilot in command told the ATSB they had completed instrument flight training where they were trained to use their flight instruments, conduct a rate 1[19] 180° turn and fly out of the cloud. The supervising instructor confirmed that the training described by the pilot was a standard syllabus requirement.

Special VFR

The operator stated that special VFR was outlined to students during their aviation legislation theory classes and that it was mainly to help the pilot to conduct a safe arrival and landing in controlled airspace.

During an interview with the ATSB, the pilot stated they had heard other aircraft in the area requesting special VFR. They had not previously used special VFR, and they were unsure of what to expect from a special VFR clearance. However, they believed it would assist in obtaining a departure clearance from the aerodrome.

Autopilot training

The pilot reported they were aware the aircraft had an autopilot but had never used it in any aeroplane and did not know how to turn it on. The pilot’s recollection was consistent with the supervising instructor who informed the ATSB that PPL‑A level trained pilots were not taught how to use an autopilot.

Regulatory information

Minimum altitude

The CASA Civil Aviation Safety Regulations 1998 Part 91 General operating and flight rules stated that aircraft flying over populus areas or public gatherings were not to be flown at less than 1,000 ft above the highest obstacle or ground feature within a 600m horizontal radius unless certain circumstances applied. In this case, the extent of cloud and its low base provided very little margin to attempt VMC operation while maintaining a minimum of 1,000 ft over the populous area to the west of Bankstown Airport.

Pre-flight weather review

The CASA Manual of Standards Part 91 Chapter 7 Flight preparation (weather assessments) requirements stated that the pilot in command must study authorised weather forecasts and authorised weather reports for:

• the route to be flown
• the departure aerodrome
• the destination aerodrome
• any planned alternate aerodromes
• any other reasonably available weather information that is relevant to the intended operation.

Furthermore, the CASA Manual of Standards Chapter 10 Matters to be checked before take-off stated:

The prescribed checks are the following:

a) check to confirm that each aerodrome, air route and airway facility that the pilot plans to use for the flight will be available, suitable and safe for use.

General competency requirement

The CASA Civil Aviation Safety Regulations 1998 Part 61 61.385 Flight crew licencing–Limitations on exercise of privileges of pilot licences—general competency requirement stated:

(1) The holder of a pilot licence is authorised to exercise the privileges of the licence in an aircraft only if the holder is competent in operating the aircraft to the standards mentioned in the Part 61 Manual of Standards for the class or type to which the aircraft belongs, including in all of the following areas:

     a) operating the aircraft’s navigation and operating systems.

CASA informed the ATSB that this included the autopilot, when fitted to an aircraft, even when the pilot did not intend to use such systems.

Related occurrences

VFR into IMC and collision with trees involving Cessna 182T, VH-TSS, 57 km south-east of Mount Surprise, Queensland, on 16 June 2025 (AO-2025-028)

About 35 minutes after initiating an in-flight diversion due to poor weather, the pilot descended the aircraft to about 500 ft above ground level, following a road. As they tracked towards rising terrain, their height reduced to about 200 ft above ground level. The pilot recalled that suddenly conditions ahead became a ‘white-out’ and they commenced a left turn and reduced the aircraft’s power in an attempt to avoid flying into the cloud. 

During the turn the aircraft entered cloud and the pilot lost visual reference with the ground. Recorded data indicated the aircraft conducted a 360° left turn with several changes in altitude and coming in close proximity to terrain before the pilot could engage the autopilot to attempt to stabilise the aircraft.

The pilot then commanded a 180° left turn using the autopilot, intending to return to visual meteorological conditions. However, as the aircraft climbed, the air speed reduced and the aircraft likely stalled, leading to a rapid descent.

The pilot received a terrain warning and immediately applied recovery actions; as they eased out of the dive, the pilot momentarily became visual with terrain before the aircraft contacted tree-tops but continued to remain airborne. 

VFR into IMC involving a Piper PA-28-181, 16.4 km south‑south‑east of Richmond Airport, New South Wales, on 24 January 2025 (AB-2025-007)

During climb, while passing 4,800 ft, the aircraft deviated from its flight plan track and began a right turn. The controller advised the pilot that they appeared to be in a right turn and the pilot informed the controller they had entered cloud. Although the aircraft was equipped with a serviceable autopilot, the pilot had not received training in its use. The pilot manually flew the aircraft to visual conditions.

Collision with terrain involving a SOCATA-Groupe Aerospatiale TB-20, VH-JTY, 65 km west of Mackay Airport, Queensland, on 28 October 2023 (AO-2023-052)

On the morning of 28 October 2023, a SOCATA-Groupe Aerospatiale TB-20, registered VH-JTY, departed Montpelier aircraft landing area, Queensland, for a VFR private flight to Palmyra aircraft landing area, Queensland. The flight was to be just over one hour duration and the pilot and their passenger were familiar with the route.

During the flight, the pilot contacted a friend at the destination for an appreciation of the weather. After the friend advised them of the prevailing conditions including cloud, the pilot replied that they would need to go through some cloud before arriving.

Around 30 NM from the destination, shortly after commencing descent for the intended landing, the aircraft began a steep descending turn to the left towards mountainous terrain. During this descent, the aircraft exceeded the airframe’s designed maximum airspeed before pitching up and passing over the top of Bull Mountain. The aircraft then entered a second steep descending turn, this time to the right, before the recorded flight path data ceased.

The wreckage was located nearby in dense forest on the north-east face of Bull Mountain. The accident site indicated that the aircraft had collided with terrain at a steep angle, and with significant forward velocity. The aircraft was destroyed and both occupants received fatal injuries.

Although the aircraft was equipped with an autopilot, the investigation safety analysis stated:

This manoeuvring indicates that the autopilot was not being used during this part [the accident sequence] of the flight.

Safety analysis

Introduction

On 15 January 2025, a Private Pilot Licence (Aeroplane) holder commenced a flight under a special visual flight rules (VFR) approval from Bankstown Airport. Shortly after departure, the aircraft inadvertently entered instrument meteorological conditions (IMC).

The safety analysis will discuss the:

• flight authorisation process
• pilot’s individual actions on the day of the incident and the factors that influenced them
• recovery from IMC.

Pre-flight briefing

The Bankstown Airport amended terminal aerodrome forecast (TAF) issued at 0650, forecast suitable weather conditions from 0800, coincident with the time the flight was authorised. The supervising instructor likely used this amended TAF to determine the expected weather at the time of departure as they reported that the extent of the cloud was supposed to improve to scattered at 1,500 ft above the airport elevation. Those predicted conditions would have provided visual meteorological conditions (VMC) for the pilot’s departure. However, the actual local weather conditions at the departure time, were less than VMC, with overcast low cloud. Neither the weather observations nor the Bankstown Airport automatic terminal information service (ATIS) were considered during the authorisation briefing.

The instructor focused the briefing on what they believed would be the most critical weather in the vicinity of the Blue Mountains and quizzed the students about the VMC requirements. Furthermore, as Bankstown Airport was a towered aerodrome, the instructor believed that a pilot operating under the VFR would not be granted a take-off clearance if the airspace was not VMC. They had not considered that the pilot would request to depart under special VFR. 

The airport observations and ATIS provided a reliable indication that extensive low cloud could be present beyond the Class D airspace boundary. Under those conditions, departure under special VFR carried a high risk of inadvertent entry into IMC, rather than a useful tool to assist in reaching more favourable flight conditions.

Additionally, the extent of cloud and its low base provided very little margin to attempt the flight visually while maintaining the required minimum of 1,000 ft operating height over the populous area to the west of Bankstown Airport. 

Neither the supervising instructor nor the pilot recalled any discussion regarding delaying the flight until Bankstown Airport met the VMC requirements. Significantly, the pilot believed that as they had been authorised, they were able to depart.

Pilot actions

VFR into IMC

To comply with the Bankstown Airport local procedures, a departing aircraft needed to maintain an altitude of 1,000 ft when departing the Class D airspace. To meet the VFR requirement to remain in VMC, the pilot needed to have 500 ft between their aircraft and any cloud above them until they reached the Class G airspace. However, with local weather observations stating cloud was at 1,100 ft and the ATIS indicating cloud was at 1,000 ft, it was not possible to depart Bankstown under standard VFR at the time of departure.

The pilot was told by the Bankstown Tower controller that the control zone was not VMC and decided to continue with the departure by requesting special VFR, the requirements of which they were unfamiliar with, instead of waiting for conditions to improve. Shortly after leaving the Bankstown Airport control zone, the aircraft inadvertently entered cloud below the lowest safe altitude, where it remained for several minutes. While in cloud, the pilot was vulnerable to experiencing spatial disorientation, which often leads to loss of control. Additionally, during that time another aircraft operating under the instrument flight rules departed from Bankstown Airport and climbed through the same altitude in close proximity.

Internal pressure

The pilot’s flight training was covered by a government-backed loan, so the cost of their flight training was deferred. However, the loan did not cover any dual recency flights required by the operator. 

The pilot’s 30-day recency period was close to expiring and they believed that the day of the occurrence was their best chance to complete a flight and avoid the cost associated with a dual check flight. In combination, these factors probably resulted in the pilot feeling self-imposed pressure to undertake a flight despite the adverse weather conditions.

Although the pilot was aware that a single take-off and landing would reset their recency and provide them with another 30 days to complete the cross-country flight, they assessed that circuits were not available at the time due to the prevailing weather. Having obtained a flight authorisation from a flight instructor to undertake the planned cross-country flight, the pilot probably felt that the navigation flight was their best chance of completing the recency requirement.

Recovery from IMC

Following the aircraft’s entry into cloud, the pilot followed their training, and the priorities of ‘aviate, navigate, communicate’, by immediately transitioning to controlling the aircraft via cockpit instruments. That action likely resulted in the aircraft remaining stable and provided the means to safely conduct a reversal turn. Given the pilot described conducting a 180° turn after entering IMC, based on their flight data track, the aircraft likely entered IMC at approximately 0848 and was in IMC below the lowest safe altitude for approximately 2 minutes before the pilot informed air traffic control.

Heading towards the Prospect Reservoir reporting point, the pilot recognised they were in a high traffic area and contacted Bankstown Tower for assistance. The tower controller was then able to assist the pilot to regain a safe operating altitude clear of cloud and return to Bankstown Airport.

Findings

From the evidence available, the following findings are made with respect to the VFR into IMC involving Piper PA-28, VH-BTN, 12 km north-west of Bankstown Airport, New South Wales, on 15 January 2025. 

Contributing factors

• Insufficient consideration of the prevailing weather conditions at Bankstown Airport by the instructor and pilot resulted in neither of them identifying that the flight could not be conducted visually until the forecast weather improvement occurred.
• The pilot used special VFR to depart Bankstown Airport with extensive low cloud present. The aircraft subsequently entered cloud, increasing the risk of:
  • spatial disorientation
  • collision with terrain while operating below the lowest safe altitude
  • collision with an aircraft operating under the instrument flight rules.
• The pilot probably felt self-imposed pressure to attempt the flight despite the adverse weather conditions. 

Other findings

• The instrument training the pilot received to escape inadvertent entry to cloud assisted in their safe return to visual conditions. 

Safety issues and actions

Safety action not associated with an identified safety issue

Basair is implementing changes to its processes regarding when students may request special VFR prior to departure, and how such requests are reviewed and approved by instructors.

Glossary

Sources and submissions

Sources of information

The sources of information during the investigation included:

• the pilot of the occurrence flight
• the supervising instructor
• the operator safety manager
• Civil Aviation Safety Authority
• Airservices Australia
• ADS-B exchange
• Flight Radar 24.

References

Airservices Australia. (2024). In-flight emergency response checklist. Airservices Australia

Civil Aviation Safety Authority. Flying into bad weather. Civil Aviation Safety Authority

Civil Aviation Safety Authority. Spatial disorientation. Civil Aviation Safety Authority

Civil Aviation Safety Authority. Navigating the margins with Special VFR. Civil Aviation Safety Authority

Rusby, L. (2024). Caught in the clouds. Flight Safety Australia. 

UK Civil Aviation Authority. (2024). VFR flight into IMC. UK Civil Aviation Authority

United States Department of Transport – Federal Aviation Administration. (2009). Advanced Avionics Handbook. Federal Aviation Administration

United States department of Transportation – Federal Aviation Administration. (2012). Instrument Flying Handbook. Federal Aviation Administration

United States Department of Transportation – Federal Aviation Administration. (2018). Fly the Aircraft First. Federal Aviation Administration.

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 occurrence flight
• supervising instructor
• operator
• Civil Aviation Safety Authority.

Submissions were received from:

• the operator
• Civil Aviation Safety Authority.

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. About ATSB reports ATSB investigation reports are organised with regard to international standards or instruments, as applicable, and with ATSB procedures and guidelines. Reports 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. 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 2025 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 Commonwealth Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this report is licensed under a Creative Commons Attribution 4.0 International licence. The CC BY 4.0 licence enables you to distribute, remix, adapt, and build upon our material in any medium or format, so long as attribution is given to the 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.

Investigation summary

What happened

On 11 January 2025, a Cessna 510, registered VH-SQY and operated by AirMed Australia (AirMed), was being used to conduct a non-emergency medical air transport flight from Narrandera Airport to Bankstown Airport, New South Wales. On board were a pilot, a flight nurse and a patient.

At 1103 local time, the aircraft departed Narrandera and approximately 30 minutes later commenced descent into Bankstown. Weather information at Bankstown reported variable wind conditions and that the runway was wet. During the landing, the pilot experienced reduced braking performance and the aircraft overran the end of the runway into muddy ground. None of the occupants were injured and the aircraft was undamaged.

What the ATSB found

The ATSB determined that during the approach, an undetected tailwind was encountered and the aircraft landed with a groundspeed higher than the minimum aquaplaning speed. In addition, there was likely standing water on the runway and the aircraft’s main landing gear tyres were worn to limits resulting in reduced braking performance. Subsequently, the pilot cycled the anti‑skid system, likely further decreasing braking performance. In combination, these factors resulted in the aircraft departing the end of the runway.

The ATSB also identified that AirMed required pilots to apply an incorrect landing distance factor, which reduced the safety margin when determining the required landing distance at a destination aerodrome. In addition, the type rating training provided by Air Link, a company associated with the operator, taught pilots to apply the same incorrect landing distance factor. Furthermore, AirMed’s procedures were unclear on how the factor should be applied, when the assessment should be conducted and how runway surface condition should be considered.

Finally, when determining the required landing distance at Bankstown, the pilot applied the incorrect landing distance factor prescribed by the operator. Subsequently, prior to descent and after obtaining the actual conditions at the aerodrome, the pilot did not identify that the landing distance available was insufficient for the landing.

What has been done as a result

AirMed updated its operations manual to require the use of a 60% landing distance factor and additional factoring for wet runway operations. Additionally, it introduced the requirement to conduct a landing distance calculation both before take-off and prior to landing, and included guidance on the applicability of options when using either tabulated data or flight planning software.

AirMed also provided training to all crew addressing the effects of tailwind, correct anti‑skid use, tyre limits and landing technique. In addition, it updated defect reporting procedures to encourage earlier reporting of anticipated maintenance requirements, and implemented a policy of tyre replacement when tread reaches 2 mm, representing 80% tyre wear.

Air Link amended training material for the C510 type rating to ensure that the correct landing distance factoring was applied and taught. In addition, past students were contacted to ensure that they understand performance requirements relating to the C510. Furthermore, it is in the process of including a new section in the endorsement training around wet weather operations, and has also implemented a policy of tyre replacement when tread reaches 2 mm.

Bankstown Airport amended the runway 11C/29C longitudinal slope information in the aerodrome manual to align with the En Route Supplement Australia slope values. Finally, while not in response to this occurrence, the Civil Aviation Safety Authority subsequently amended the performance section of the Part 121 guidance material as part of its continuous improvement process. These changes included:

• the addition of a section specifying that landing performance must be checked both pre‑flight and in-flight
• advice that actual landing distance data cannot be used to satisfy in-flight replanning operations
• provision of a list of known aircraft types, including the C510, that must not use actual landing distance data for in-flight landing distance calculations.

Safety message

The use of safety margins on top of calculated take-off and landing distances provides mitigation for a wide range of issues that impact aircraft performance, including unexpected environmental conditions. Operators must be familiar with any factoring applicable to their operation and should adjust procedures appropriately when regulations change. For private pilots, while not mandated, the use of safety margins is highly recommended. These recommended safety margins can be found in the Civil Aviation Safety Authority (CASA) Advisory Circular (AC) 91-02 Guidelines for aeroplanes with MTOW not exceeding 5 700 kg - suitable places to take off and land, and should be applied in conjunction with any guidance given in the aircraft flight manual.

This occurrence also highlights the limitations on accurate and timely reporting of runway surface condition, particularly following a period of intense rainfall. Only 3 mm of standing water is required for a runway to be considered contaminated, and this depth of water can accumulate rapidly before the runway surface condition is able to be assessed. Furthermore, when landing on an un‑grooved runway, braking may be degraded when the runway is very wet but not yet classified as contaminated, with significant additional stopping distance required.

The occurrence

On 11 January 2025, a Cessna 510, registered VH‑SQY and operated by AirMed, was being used to conduct a non‑emergency medical air transport flight from Narrandera Airport to Bankstown Airport, New South Wales (Figure 1). On board were a pilot, a flight nurse and a patient.

Figure 1: Incident flight 

Source: Google Earth, annotated by the ATSB

The aircraft had been repositioned earlier that morning from Wagga Wagga Airport to Narrandera Airport, where the flight nurse and patient boarded for the flight to Bankstown. Prior to departure from Wagga Wagga, the pilot obtained a weather forecast for both Narrandera and Bankstown (see the section titled Meteorology) and added sufficient fuel for both flights. The forecast conditions for Bankstown indicated rain and possible thunderstorms (see the section titled Forecast conditions) and the pilot determined that the aircraft would be below the maximum landing weight permitted in these conditions by the landing distance available charts (see the section titled Pilot assessment of landing distance available).

The aircraft departed Narrandera at 1103 local time and, approximately 30 minutes later, the pilot obtained the automatic terminal information service (ATIS)[1] information ‘Echo’ for Bankstown, prior to commencing descent. The pilot conducted the instrument approach procedure for runway 11C[2] and reported becoming visual with the runway at around 800‍–‍900 ft. The pilot recalled that the runway appeared wet, however they did not see any indications of standing or pooled water. Additionally, while they did not recall seeing the windsock, they reported that they did not feel as though there was a tailwind.

The aircraft commenced the round out for landing at 1156:32, and the pilot reported touching down firmly within the touchdown zone, deploying the speed brake and lowering the nose wheel prior to applying the brakes. The pilot stated that, despite braking, no deceleration or braking action was felt. They continued to hold brake pressure, expecting the anti‑skid system to activate (see the section titled Anti‑skid system), however the lack of discernible braking continued.

By this point, the pilot considered that the aircraft had passed the point on the runway where a go‑around could be safely conducted. Observing no system failure or warning indications in the cockpit, the pilot elected to cycle the anti‑skid system. They turned the anti‑skid system off, released and re‑applied the brakes. With no change in braking action the pilot again released the brakes, turned the anti‑skid back on, then re‑applied and held the brakes.

Realising that the aircraft would not stop prior to the end of the runway, the pilot advised air traffic control (ATC) that they could not stop. They then steered the aircraft slightly to the right to avoid the lights at the end of the runway. Departing the end of the runway at a groundspeed of 28 kt, the aircraft entered muddy ground and travelled another 30 m in a right turn before coming to a stop (Figure 2). The aircraft was undamaged and the pilot, flight nurse and patient were uninjured. After advising ATC of the situation and shutting down the aircraft, the patient was transferred to ground transport and the aircraft was recovered to a hanger.

Figure 2: VH-SQY after runway excursion

Source: Supplied

Context

Pilot

The pilot held an air transport pilot licence (aeroplane) issued in 2017 and a class 1 aviation medical certificate. They had accumulated 6,954 flight hours, of which 133 hours were operating the Cessna 510. In the previous 90 days, the pilot had accumulated 128 hours, all in the Cessna 510. The pilot had completed a type rating for the aircraft and an instrument proficiency check in October 2024 with Air Link, a company associated with the operator. The pilot had also completed line training with Air Link and had conducted operations for them, prior to commencing operations for AirMed.

Aircraft

General information

VH-SQY was a Cessna 510 Citation Mustang equipped with 2 Pratt & Whitney Canada PW615F‑A turbofan engines. The aircraft was manufactured and first registered in 2010 and was registered with the operator in 2019. It was in medical configuration, in which 2 seats and a cabinet in the main cabin were replaced with a stretcher and medical equipment.

At the time of the incident, the aircraft had accumulated 5,721 hours total time in service and was being maintained in accordance with the Cessna 510 maintenance manual. The last periodic inspection was conducted in December 2024, and the maintenance release showed no outstanding items. 

Main landing gear tyres

VH-SQY was equipped with 2 Michelin main landing gear (MLG) tyres. Maintenance records showed that both MLG tyres were last replaced in October 2024, after conducting 255 landings. Since that time, the aircraft had conducted 239 landings including the incident flight.

The manufacturer required the MLG tyres to be inflated to a loaded pressure of 88 PSI. Both the maintainer and the pilot reported that, while the tyre pressure was not recorded or checked, the pressure appeared to be normal with no signs of over or under inflation.

The tyre manufacturer provided guidance on tyre removal criteria (Figure 3) which stated:

Removal criteria for normal wear is based on remaining tread rubber as determined by groove depth or exposure of textile/steel ply material…
NORMAL REMOVAL WEAR LIMIT: Remove the tire when the wear level reaches the bottom of any groove at one point up to a maximum 1/8 of the circumference.
NOTE: When the NORMAL REMOVAL limit is reached, the tire should be replaced. If it is necessary to continue the tire in service beyond the normal wear limit, the tire should be removed either at the next maintenance base or upon reaching the EXPOSED CORD LIMIT, whichever occurs first. At the EXPOSED CORD LIMIT the tire should be removed and replaced.

Figure 3: Michelin tyre wear guidance

Source: Michelin, annotated by the ATSB

During the post-incident inspection, the maintainer determined that both main landing gear tyres were worn to limits (Figure 4) and identified evidence of flat spotting, potentially due to the wheels previously locking up under braking. The maintainer further advised that the tread remaining on the left and right MLG tyres was measured to be 0.013 inches (0.3 mm) and 0.019 inches (0.5 mm) respectively. Comparatively, the tread of a new tyre was reported to be 0.26‍–‍0.29 inches (about 7 mm), indicating that 4‍–‍7% of the original tread was remaining. Both tyres were subsequently replaced before the aircraft was released back to service. 

Figure 4: VH-SQY main landing gear tyres post‑incident

Source: Supplied, annotated by the ATSB

The pilot reported that they had inspected the condition of the tyres as part of the daily inspection of the aircraft prior to commencing operations for the day. They further reported that, while they identified that the centre tread on the tyres was low, they considered that as there was sufficient depth on the outside tread with no exposed cord the tyres were serviceable.

Anti‑skid system

The aircraft was equipped with an anti‑skid system to provide maximum braking efficiency across all runway surfaces and conditions. The anti‑skid system detects if the speed of any main landing gear wheel was too slow for the aircraft’s speed and released the brake momentarily to allow the wheel rotation to increase, preventing it from skidding. Anti‑skid systems are designed to reduce landing distance and minimise the potential tyre damage which can occur when a wheel is locked.

The aircraft was also equipped with a cockpit warning message to indicate when the anti‑skid was inoperative. While landing with anti‑skid inoperative was permitted, pilots were advised that doing so required the landing distance to be increased by between 39‍–‍45%.

In a normal landing with the anti‑skid system operative, the aircraft flight manual (AFM) advised pilots to apply brakes after nose wheel touchdown. The AFM further advised that:

to make sure of proper braking on water, snow, and ice-covered, hard-surfaced runways, and all unimproved surfaces, it is necessary for the pilot to apply maximum effort to the brake pedals throughout the braking run. When the system detects a skid and releases the applied brake pressure, any attempt by the pilot to modulate braking can result in an interruption of the applied brake signal and may increase stopping distance significantly.

The manufacturer advised that the anti‑skid system was not certified for turning off then on during a landing. They further advised that turning the system off during a landing roll may result in flat spotting the tyres if the anti‑skid was actively controlling a skid, especially on a wet runway. Additionally, when the system was powered on, it took several seconds to self‑test, during which time it would not function. 

Meteorology

Forecast conditions

The Bureau of Meteorology (BoM) issued both a Graphical Area Forecast (GAF) for the area including Bankstown Airport and a terminal area forecast (TAF) for the aerodrome that covered the pilot’s expected landing time. The GAF was initially issued at 0308 that morning and described the weather to expect around Bankstown as including:

• broken cloud from 2,000‍–‍10,000 ft[3]
• periods of scattered rain showers with towering cumulus clouds and broken cloud at 500 ft
• isolated thunderstorms with heavy rain, becoming occasional from 1300.

The GAF was re‑issued as part of the regular cycle at 0926 with no changes, other than that the thunderstorms were no longer expected to produce heavy rain and were expected to remain isolated. 

The TAF for Bankstown Airport was issued and then amended at 0352. It described the weather at the airport for the expected arrival time as:

• wind from 050°M at 14 kt, light showers of rain and broken cloud at 2,000 ft
• periods of up to 60 minutes of showers of rain with wind gusting 15‍–‍25 kt, broken cloud at 800 ft and visibility reduced to 2,000 m
• possibility of thunderstorms for periods up to 60 minutes with variable strong winds, broken cloud at 500 ft and visibility reduced to 1,000 m.

A new TAF was issued at 1026, with the only change being that the wind was now expected to be from 060°M at 10 kt.

Reported conditions

Prior to descent, the pilot reported that they listened to the automatic terminal information service (ATIS)[4] information ‘Echo’ for Bankstown Airport to obtain the reported conditions at the airport. The information included that:

• runway 11 left, centre and right were in use
• runway surface condition code was 5,5,5. Whole runway was wet
  (see the section titled Assessment of runway surface condition)
• wind was variable at 8 kt
• visibility reduced to 3,000 m in rain
• cloud was scattered at 800 ft, scattered at 1,200 ft and broken at 2,000 ft
• temperature was 23 degrees and QNH[5] was 1014.

Recorded conditions

Wind

The BoM weather station at Bankstown Airport recorded the mean direction of the wind at 1‑minute intervals in addition to the minimum, mean and maximum wind strength. Additionally, the standard deviation of the wind direction was recorded as a measurement of the variability of the wind direction within each minute.

The mean wind direction varied significantly between 1130‍–‍1215 (Figure 5). The recorded wind changed from a headwind to a tailwind on runway 11C, 6 minutes prior to VH-SQY landing. However, at around this time, the variability of the wind direction increased. At the time of the landing, the mean wind was recorded as a 6 kt tailwind. Subsequently, the tailwind further increased slightly before decreasing again, becoming a headwind again 14 minutes after the landing.

Figure 5: Runway 11C mean tailwind and wind direction variability 1130‍–‍1215

Source: ATSB

Rainfall

BoM observations recorded that Bankstown Airport received 2.8 mm of rain from 0900‍–‍1130 that morning. At 1133, heavy rain began to fall and continued to fall until 1155, 1 minute prior to the aircraft landing (Figure 6). During this 23‑minute period, 15 mm of rain was recorded. This represented a rainfall rate of 39 mm/hr, significantly higher than the threshold of 10 mm/hr required to be classified as heavy rain. Satellite imagery and CCTV footage confirmed that significant rain was observed at and around the aerodrome prior to the aircraft landing.

Figure 6: Bankstown Airport recorded rainfall 1130‍–‍1215

Source: ATSB

Runway surface condition

While the runway surface condition was reported as wet on the ATIS, the ATSB identified evidence of standing water on the runway at the time VH‑SQY landed. CCTV footage recorded the latter portion of the landing, during which spray was observed being ejected from beneath the aircraft during its ground roll (Figure 7).

Figure 7: CCTV images of water spray during landing

Source: Google Earth and Bankstown Airport, annotated by the ATSB

Additionally, a photograph of runway 11C taken at 1202, 6 minutes after the runway excursion, showed water on the runway (Figure 8). A subsequent photograph taken 9 minutes later showed that the amount of water on the runway had visibly reduced over this time.

Figure 8: Runway 11C surface after incident

Source: Supplied, annotated by the ATSB

Air traffic control observations

Air traffic control did not advise the pilot of any tailwind when giving an initial landing clearance at 1154 or when a subsequent landing clearance was given at 1155. After the incident, the next aircraft to arrive at Bankstown was advised of an occasional tailwind of 5 kt prior to receiving a landing clearance for runway 11L at 1159.

While the ATSB did not interview the air traffic controllers who were on duty at the time, Airservices Australia advised that an internal occurrence review was conducted into the incident which reported that a tailwind was not observed by the controller at the time that a landing clearance was given to VH‑SQY. They further advised that it was likely that controllers were using instantaneous wind readings in conjunction with visual observations to inform their assessment of wind conditions.

Recorded data

The ATSB analysed flight data recorded by the aircraft’s Garmin G1000 avionics. This data recorded specific flight and system parameters every 1‍–‍2 seconds throughout the flight, including during the landing and runway excursion. The aircraft was not fitted with a flight data recorder or a cockpit voice recorder, nor was it required to have them installed.

The data from the G1000 showed that on final approach, the aircraft was at 50 ft above ground level (AGL) approximately 240 m before the displaced threshold before arriving at an aim point short of the first touchdown marker (Figure 9).

Figure 9: VH-SQY flight path and landing

Source: Google Earth, annotated by the ATSB

At 1156:32 the aircraft commenced the round out and flare approximately 135 m past the displaced threshold at which point the aircraft’s groundspeed was 102 kt. The recorded data did not contain a specific data point to indicate when the aircraft was on the ground, however a positive G indication, consistent with a touchdown, was recorded at 1156:38, 430 m past the displaced threshold. At this time, the aircraft’s groundspeed had decreased to 93 kt. The aircraft’s groundspeed continued to decrease with no discernible change to the deceleration rate until 1156:58, at which time 140 m of the pavement remained. Subsequently, the aircraft departed the end of the runway at 1157:05 at a groundspeed of 28 kt.

The data recorded both the indicated airspeed and groundspeed of the aircraft, enabling the headwind and tailwind component of the wind to be determined (Figure 10). At approximately 550 ft, the aircraft was experiencing a headwind of 9 kt. As the aircraft descended on the approach, the headwind decreased prior to switching to a tailwind at approximately 250 ft. As the aircraft continued its descent, the tailwind increased up to a maximum of 6.3 kt when the aircraft was 50 ft AGL, consistent with the wind recorded at the airport. After peaking at 50 ft, the tailwind decreased throughout the remainder of the landing.

Figure 10: VH-SQY calculated wind on final approach and landing

Source: ATSB

Bankstown Airport

Runway environment

Bankstown Airport’s runway environment consisted of 3 parallel runways. The centre runway, 11C/29C, was the longest runway. It was typically used for arrivals and departures under the instrument flight rules (IFR) due to associated instrument approach and standard instrument departure procedures. The runway was un-grooved, and the runway surface was asphalt.

The En Route Supplement Australia (ERSA) provided information on Bankstown Airport, including runway dimensions, take-off and landing distances, runway slope and local procedures for operating at the aerodrome. The ERSA advised that runway 11C had a displaced threshold of 97 m and a landing distance available (LDA) of 1,259 m. The pavement surface continued for a further 60 m, however this section was not permitted to be used for either take-off or landing. The reciprocal runway 29C had no displaced threshold and a LDA of 1,356 m.

Runway longitudinal slope

The ERSA described the longitudinal slope of the runway as:

Slope W end 0.5% down to E. Centre 0.2% up to E. E end 0.2% down to W

The ERSA did not contain information on how this description should be used to determine a runway slope value for landing and take-off performance calculations. Bankstown Airport survey information detailed how the slope described in the ERSA was constructed (Figure 11). The survey information identified that the threshold‑to‑threshold slope was 0.15% up to the east. This would have been the runway slope applicable to performance calculations for an aircraft landing on runway 11C.

Figure 11: Runway 11C longitudinal slope

Source: Google Earth, annotated by the ATSB

Bankstown Airport maintained an aerodrome manual, as required under Part 139 (Aerodromes) of the Civil Aviation Safety Regulations (CASRs). The manual included technical information regarding the longitudinal slope of runway 11C/29C and reported:

• The runway slope was 1.12% slope to the south-west.
• In a different section of the manual, the runway was a code 3 non‑precision approach runway with an overall longitudinal slope of 1.34%, whereby the current standard was 1%. This was identified as non‑compliant with the current standards, however, was being used under grandfathering provision of the regulations.

An independent aerodrome technical inspection (ATI) was conducted for the aerodrome in December 2023. The inspection included a visual inspection of all movement area pavements to appraise compliance with CASR Part 139. The inspection reported that the overall longitudinal slope of runway 11C/29C was 1.34%, consistent with one of the statements in the aerodrome manual, but not consistent with survey information.

The ATSB sought clarification from Bankstown Airport regarding the variation between the runway 11C/29C longitudinal slopes reported in the ERSA, aerodrome manual, ATI and survey documentation. Airport personnel advised that the survey information was correct and that the aerodrome manual and ERSA would be amended.

Runway transverse slope and drainage

The aerodrome manual stated that the transverse slope values required by the CASR Part 139 Manual of Standards (MOS) had not been exceeded for runway 11C/29C.

The ATI did not contain a statement regarding assessment of the transverse slope of the runway. However, it did state that the drainage infrastructure of the runway:

appeared to be operating effectively at the time of inspection within minimal areas of ponding observed.

The ATSB was advised by Bankstown Airport that the ATI offered only a visual inspection of the transverse slope and that the slope was typically determined during the runway design process. Both the pilot and the operator reported that discussions had occurred between representatives of the operator and the airport regarding what they considered to be poor runway drainage. Bankstown Airport management advised that they were not aware of any conversations where this was discussed.

Assessment of runway surface condition

Bankstown Airport had procedures for assessing and reporting runway surface conditions and associated braking action under the global reporting format (GRF). The procedures defined the steps required to determine the runway condition report (RCR), a standardised report relating to runway surface conditions, and their effect on an aircraft’s landing and take-off performance.

The RCR was provided in 2 parts, a runway condition code (RWYCC) and a surface description. Additionally, each runway was divided into approximate thirds, with an RCR being determined separately for each of these thirds. The RWYCC was initially assigned based on a runway surface description (Table 1).

Table 1: Runway surface description to assign initial RWYCC

After initial assignment of an RWYCC from the runway surface description, receipt of 2 or more pilot reports of braking action less than that expected, could result in the description being downgraded. 

During tower hours, ATC was trained to determine if the runway was completely dry or wet and could create the RCR when conditions were dry or wet for the whole runway. Further to this, ATC was able to request the aerodrome reporting officer (ARO) to conduct a runway inspection to assess the runway surface. AROs were also required to carry out inspections after severe weather events, so long as the weather conditions would not pose a safety hazard.

The assessed RCR was advised on the ATIS. Additionally, if the runway surface condition was determined to be slippery wet, or had standing water, a NOTAM[6] was required to be submitted containing details of the adverse RCR.

The ATIS ‘Echo’ current at the time of the incident contained an RCR of 5,5,5, whole runway wet (see the section titled Reported conditions). ATC did not report having received any reports of adverse braking from other pilots prior to the incident that would have required the RCR to be amended. After the incident, while attending to VH‑SQY, the ARO advised the tower controller that there was no observed standing water on runway 11C. Subsequently, when the ATIS was updated to ‘Foxtrot’ at 1213 to advise of a disabled aircraft, the RCR remained the same.

Air traffic control requirements

Airservices Australia’s Manual of Air Traffic Services (MATS) included procedures for ATC relating to the issuing of an ATIS, and the conditions under which it should be revised. These procedures required that an ATIS include:

Surface wind direction and speed, including significant variations

Wind direction was further required to be reported as one of:

SINGLE MEAN DIRECTION;

TWO VALUES representing variation in wind direction, whenever:
i) the extremes in wind direction vary by 60 degrees or more; or
ii) the variation is operationally significant (e.g. the variation is less than 60 degrees, but the variation from the mean results in either a tailwind, and/or significant crosswind component on a nominated runway) (e.g. WIND VARYING BETWEEN [DIRECTION] AND [DIRECTION]);

VARIABLE, where it is not possible to report a mean wind direction, such as:
i) in light wind conditions (3 kt or less); or
ii) the wind is veering or backing by 180 degrees or more
(e.g. passage of thunderstorm, or localised wind effect).

The wind component of the ATIS was also required to:

Quote significant crosswind and any tailwind as:
a) MAXIMUM CROSSWIND (speed) KNOTS [RUNWAY (number), if
applicable]; and
b) MAXIMUM TAILWIND (speed) KNOTS [RUNWAY (number), if applicable].

MATS also advised on wind limitations when nominating a runway. When the runway was dry, a runway could not be nominated for use when the tailwind exceeded 5 kt. When the runway was not completely dry, a runway could not be nominated for use when there was any tailwind component.

ATC was required to revise an ATIS and assign a new code letter when certain items changed and were expected to remain that way for at least 15 minutes. This included changes to an RCR or when wind direction varied by 10°.The CASR Part 179 (Air Traffic Services) MOS also required that:

Changes to ATIS wind information must be provided to pilots with a take-off or landing clearance if it is considered that it would be of significance to the aircraft operation.

Landing performance

Aircraft flight manual

Landing performance data

The Cessna 510 AFM contained performance data for use in calculating the landing distance required (LDR) at a destination aerodrome. This data was contained in 2 sections. The first section provided data to calculate the landing distance when the runway was forecast to be dry. This section of the AFM was marked as approved by the United States Federal Aviation Administration (FAA), the organisation that originally issued the aircraft’s type certificate. The performance data was based on several assumptions including:

• the landing was on a paved, dry runway
• landing preceded by a steady 3° angle approach down to the 50 ft height point with airspeed at V_REF[7] in the landing configuration
• maximum wheel braking was initiated immediately on nose wheel contact and continued throughout the landing roll
• winds were to be taken as the tower winds 32.8 ft (10 m) above runway surface
• factors of 50% of the headwind, and 150% of the tailwind had been applied to winds.

The second section of the AFM provided performance data for landing on wet, slush, snow‑ and ice‑covered runways. This section was marked as advisory information and stated that:

The following information is considered the most accurate and practical guidance material available for wet and contaminated runway operations. This advisory information is not FAA approved.

The section also stated that:

The published limiting maximum tailwind component for this airplane is 10 knots, however, landings on precipitation covered runways with any tailwind component are not recommended.

Advisory and unapproved information

The Civil Aviation Safety Authority (CASA) Advisory Circular (AC) 21‑34 Aircraft flight manuals contained information relating to approved and unapproved sections of an AFM and advised that:

 - Approved parts of the AFM are approved by the applicable national aviation authority (NAA), based on the type certification requirements effective at the time of certification. 

 - Unapproved parts of the AFM are provided by the manufacturer additionally, as deemed necessary for the safe operation of the aircraft, and cannot conflict with approved parts of the AFM. Each approved part of the AFM is clearly distinguished from any unapproved part of that AFM.

CASA also published Civil Aviation Safety Regulation (CASR) Part 135 Acceptable means of compliance and guidance material (AMC/GM) - Australian air transport operations—smaller aeroplanes which provided guidance on complying with required performance data calculations. It stated that:

Some performance information presented in AFM or AFM supplements may be advisory information only and should not be used to determine performance in compliance with the provisions of regulations 135.345 and 135.350 [Take-off performance and Landing performance]. Caution should be exercised when using advisory material or when using third-party performance calculations as the results may not be based on the required AFM provided certification data.

Similar advice was contained in CASR Part 121 Acceptable means of compliance and guidance material (AMC/GM) - Australian air transport operations—larger aeroplanes.

The ATSB sought clarification from CASA as to the applicability of data from unapproved sections of an AFM for use in flight planning. They advised that this data could not be used for performance planning, in part because the advisory information was not developed in accordance with standardised conditions.

Landing distance requirements

Safety Margins

Take-off and landing performance data contained in an AFM was obtained through formal testing using specific criteria. It was therefore unlikely that a pilot could replicate the testing performance during normal flying conditions. For this reason, additional distance was added to the calculated distance to provide a safety margin. While only recommended for private operations, the use of safety margins was required when conducting air transport operations.

CASA AC 91-02 provided guidance on the purpose of safety margins including that:

These additional safety margins mitigate risks associated with a range of issues that impact on aircraft performance, including but not limited to:

 - pilot inaccuracies compared to performance flight testing (excess landing speed, excess height over threshold, increased float before touchdown, delayed use of braking and deceleration devices, inaccurate application of maximum braking techniques)

 - runway characteristics

 - aerodrome density altitude

 - changed external drag configuration of the aeroplane

 - underperforming engine compared to that used for performance testing.

Landing distance factor

CASR Part 135 - Australian air transport operations—smaller aeroplanes, under which this flight was conducted, prescribed certain landing performance requirements. As part of these requirements, if the aircraft was a jet‑driven, multi‑engine aircraft with a maximum take‑off weight (MTOW) of greater than 2,722 kg, such as the Cessna 510, then the performance calculations were required to be conducted in accordance with CASR Part 121, the regulations for larger aeroplanes.

CASR Part 121 required that a pilot determine that the runway at the planned destination aerodrome had sufficient landing distance available (LDA) to bring the aircraft to a stop. For a jet‑engine aeroplane, such as the Cessna 510, the aircraft was required to be shown to able to stop within 60% of the full LDA (Table 2). This calculation was required to be conducted both prior to departure using forecast conditions and in‑flight when actual aerodrome conditions were obtained.

If the runway surface condition was expected to be wet or contaminated, an additional 115% factor was required to be applied as a further safety margin. If the AFM contained landing performance data specific to wet or contaminated runways an alternative calculation was available. However, if this data was contained in an advisory or unapproved section of the AFM, as it was for the Cessna 510, it was not eligible to be used (see the above section titled Advisory and unapproved information).

Table 2: Summary of landing distance required calculations

The regulations stated conditions to be considered when calculating LDR, which included:

• runway surface condition
• forecast wind speed and direction. Unless otherwise accounted for in the performance data in the AFM, 50% of the headwind and 150% of the tailwind
• expected runway to be used
• expected landing weight
• aerodrome elevation
• runway slope if greater than 1%.

Actual landing distance data

CASR Part 121 allowed a single, less restrictive landing distance factor of 15% to be used when determining LDR in‑flight for aircraft where the AFM contained actual landing distance (ALD) data. CASR Part 121 AMC/GM listed key points surrounding the use of ALD including:

 - Actual landing distance information is intended to show landing performance that can realistically be achieved by flight crews in commercial operations.

 - This is distinct from landing performance demonstrated by test pilots during flight tests for aircraft type certification.

The AMC/GM also stated that to be classified as ALD data, performance data was required to be accordance with International Civil Aviation Organisation (ICAO) Annex 8 standards and that:

the applicability is also limited to aeroplanes intended for the carriage of passengers or cargo or mail in international air navigation. These are known in some States as transport category aeroplanes. This has resulted in some aeroplanes that are seemingly captured by the requirements of ICAO Annex 8 Part IIIB not having performance data that is required to be in accordance with those requirements.

CASA confirmed that performance data in the Cessna 510 AFM did not constitute ALD data.

Landing in very wet conditions

CASA guidance material contained advice for operators and flight crew on landing in very wet conditions which stated:

Operators and flight crews should be aware that the landing distance factors mentioned above – whether based on type certification testing or actual landing distance data provided by OEMs [original equipment manufacturer] separately – may not provide adequate stopping distance in very wet but not yet contaminated runway surface conditions.

Issues that contribute to such incidents include runway conditions such as texture (polished or rubber contaminated surfaces), drainage, puddling in wheel tracks and active precipitation. For un-grooved runways, wheel braking may be degraded when the runway is very wet. Research conducted by the FAA has indicated that 30 to 40 percent of additional stopping distance may be required in certain cases where the runway is very wet, but not yet classified as contaminated.

In order to manage some of the risks associated in operating to very wet runways, it is recommended that operators consider the landing safety factor of 1.15 (which is the difference between 1.67 and 1.92 for type certification data and the value mentioned in the actual landing distance data) to be a minimum value.

Flight planning software

The operator utilised third party flight planning software from Aircraft Performance Group (APG) for performance calculations. Access to this software and underlying performance data was available to pilots through the following means:

• the APG iPreFlight App available on the pilot’s tablet
• the APG Atlas website, available via a computer with an internet connection
• tabulated data for individual aerodromes, available as PDF documents via the electronic flight bag (EFB) on the pilot’s tablet.

The APG iPreFlight App and APG Atlas website provided an interface into which pilots entered the destination airport and runway, forecast or actual conditions and estimated landing weight. Additionally, options were available to configure how the landing distance was calculated which included:

• landing distance factor: 60%, 80% or unfactored
• wet runway calculation method: 115% or use of AFM advisory data
• other runway surface conditions: including 0.125 inches (3 mm) of water, snow and slush.

Of these options, 80% landing distance factor was selected by default.

The tabulated data provided both take-off and landing performance data for an individual airport. The landing performance data (Figure 12) was presented as a maximum landing weight (MLW) permitted and the LDR required at this weight, across a discrete set of temperature and wind conditions. Tables for both dry and wet (115%) runway conditions were provided, with 60%, 80% landing distance factors in addition to unfactored data. If the landing distance required for the selected runway was not available, then ‘NA’ was listed as the MLW and the actual distance required was specified.

Figure 12: Extract of tabulated landing performance data for runway 11C

Source: Supplied, annotated by the ATSB

Type rating training

The pilot completed a type rating for the Cessna 510 with Air Link, a company related to the operator. The ground school component of the type rating contained a section on aircraft performance, which included the calculation of landing distance required. The trainer reported that this training included:

• a review of relevant CASR Part 135 and CASR Part 121 requirements for landing distance calculation
• use of the advisory section of the AFM to calculate landing distance required under CASR Part 135 on a wet and contaminated runway
• use of the APG flight planning software on a company EFB to conduct the same landing distance calculation.

The pilot recalled that, during ground training and during the type rating test, an 80% landing distance factor was used. The trainer confirmed that use of an 80% landing distance factor was taught during the type rating. Air Link advised that this factor was adopted as a safety margin in consultation with CASA when both Air Link and AirMed were initially approved under previous regulations as there was no factoring required under the previous legislation.

Operator procedures

Procedures for determining landing distance available

The operator advised the ATSB that, consistent with the training provided by Air Link, pilots were required to apply an 80% landing distance factor when determining LDA. The pilot also reported that they consistently used an 80% factor.

The operator’s procedures contained requirements for pilots when determining landing distance and advised that:

The means to determine maximum allowable take-off and landing weights are based upon:

 - airport characteristics consisting of airport elevation, runway gradient and length, runway contaminants, obstructions within the take-off path,

 - airport/environmental conditions consisting of temperature, wind and pressure altitude

 - aircraft configurations consisting of power settings, flap settings, bleed configurations and MEL [minimum equipment list] inoperative components.

 - specified factoring (set by company, in accordance with CAO 20.7.1 [historical regulation])

The procedures further stated that:

The calculation of aircraft performance must be considered prior to dispatch, as part of the pre-flight planning process. 

Additional procedures for landing on a wet runway

The operator provided additional guidance for operating on wet or contaminated runways which stated:

Due to the large number of variables involved no exact formula has so far been found, but an empirical result of a 15% increase in the overall distance required has been accepted in the US [United States] and in other countries as providing an acceptable correction for landing.

It is desirable to apply some correction for take-off when the runway is considered to be significantly wet, so as to provide a distance margin to offset the reduced braking likely to arise in the accelerate-stop manoeuvre, whenever the take-off is likely to be distance limited. For take-off and landing, the 15% increase is considered to be appropriate.

It also provided the following guidance for adjusting landing distance available when expecting to land on a wet runway:

Obtain the LDA, and using only 0.85 X LDA as the effective distance available, derive a ‘wet’ length limited landing weight from the general chart in the manual.

Derive the approach climb limit in the usual way, and observe this and the structural limit.

If the ‘wet’ length limit is the most restrictive consider using another runway to provide better protection.

Note: That in both the take-off and landing cases, the use of 1.67% of the overall distance will provide an acceptable margin in that portion of the distance used. In most cases, the distance available for decelerating will be approximately doubled by this means.

Stabilised approach criteria

The operator’s procedures contained requirements for a stabilised approach that stated:

An approach to land must be stabilised by the FAF [final approach fix] in IMC [instrument meteorological conditions] and by 300 ft above the airport elevation in VMC [visual meteorological conditions]. An approach is stabilised when all of the following criteria are met:

 - The aircraft is on the correct flight path.

 - Only small changes in heading and pitch are required to maintain the correct flight path.

 - The aircraft speed is not more than V_REF +15 IAS [indicated airspeed] and not less than V_REF +5.

 - The aircraft is in the correct landing configuration.

 - The sink rate is no greater than 1,000 ft/min.

 - Power setting is appropriate for the configuration.

 - All briefings have been conducted.

The operator further advised that the expectation was for pilots to fly the aircraft within the specified range as they approach the field, reducing airspeed so that the aircraft was at V_REF at touchdown.

Pilot assessment of landing distance available

Pre-departure

The pilot reported that prior to departure, as part of their pre-flight planning process they assessed the landing distance available at Bankstown using the APG tabulated landing distance data. Given the forecast conditions (see the section titled Forecast conditions), they determined that the runway would likely be wet on arrival, therefore they consulted the section of the data for a wet runway. Rather than using the wind forecast from the TAF, they used for a more conservative 5 kt tailwind on arrival. Using the 80% landing distance factor in accordance with operator procedures, a more conservative temperature of 29° and interpolating between the values for nil wind and a 10 kt tailwind, they determined that the maximum landing weight was approximately 7,700 lb for runway 11C at Bankstown (Figure 13).

Figure 13: Pre-departure landing distance calculation

Source: Supplied, annotated by the ATSB

The pilot had also determined that the landing weight of VH‑SQY was expected to be 7,089 lb based on calculated take‑off weight and anticipated fuel consumption. Therefore, as the aircraft was expected to be below the maximum landing weight, the aircraft could depart.

In-flight

The pilot reported that upon receiving the ATIS they again conducted an assessment of the landing distance available at Bankstown using APG tabulated data and the reported conditions (see the section titled Reported conditions). Considering that the variable 8 kt wind reported could be all tailwind, the pilot used a more conservative 10 kt tailwind. Again, using the 80% landing distance factor in accordance with operator procedures, the pilot determined that the maximum landing weight was 7,401 lb. The pilot recalculated the estimated landing weight with the current fuel load as approximately the same as that estimated prior to take‑off.

As the aircraft was expected to be below the weight assessed in the chart, they determined that the landing could be conducted. In addition, the pilot advised that they had decided that if they observed a tailwind greater than 5 kt during the approach, they would request to land on the reciprocal runway 29C. At this point, the pilot also determined 89 kt as the required V_REF for the aircraft, for the expected landing weight.

ATSB assessment of landing distance required

The ATSB calculated the landing distance required using the 60% landing distance factor required for operating the Cessna 510. A pre‑departure assessment was conducted using conditions from the TAF available prior to departure from Narrandera. An in‑flight assessment using the conditions reported on the ATIS prior to descent was also performed (Table 3). The calculations were conducted using APG flight planning software, software from the manufacturer and using performance data from the AFM with the results consistent across the 3 methods. The pre‑departure calculation determined that a landing distance of approximately 1,230 m was required on runway 11C, less than the 1,259 m available. However, the in‑flight calculation determined that approximately 1,530 m was required, greater than that available.

Table 3: ATSB assessment of landing distance required

Wet or contaminated runway landing performance

Dynamic aquaplaning

Dynamic aquaplaning (also known as hydroplaning) can occur when an aircraft lands on a runway contaminated with standing water, slush or wet snow. Above a certain groundspeed and with sufficient contaminant, the tyre is lifted off the runway surface. This can have serious adverse effects on ground controllability and braking efficiency.

The depth of standing water required for dynamic aquaplaning to occur is generally accepted to be 3 mm (approximately 0.125 inches). This is also the depth required for a runway surface condition to be considered contaminated rather than wet.

The minimum speed above which dynamic aquaplaning can occur is a function of tyre pressure. Two different speeds are often quoted depending on whether the tyre is rotating. A lower speed is considered for a non‑rotating tyre as is the case immediately on touchdown (Table 4).

Table 4: Generally accepted Cessna 510 main landing gear aquaplaning speeds

The operator’s procedures contained guidance for pilots regarding aquaplaning and stated:

The formula used to determine the speed at which a tyre is likely to hydroplane [aquaplane] after touchdown on a wet runway is: Hydroplane speed = 7.7√𝑇𝑦𝑟𝑒𝑃𝑟𝑒𝑠𝑠𝑢𝑟𝑒𝑃𝑆𝐼

From the above formula, the Citation Mustang’s nose gear hydroplane speed is about 86 knots and the main gear about 72 knots. Above these speeds hydroplaning may occur.

The manufacturer advised that the aircraft’s minimum aquaplaning speed for performance calculations was 84 kt. The operator’s speed was consistent with that for a non‑rotating tyre, while the manufacturer’s speed was consistent with that for a rotating tyre.

Recorded data showed that the groundspeed of the aircraft was above both the rotating and non‑rotating tyre minimum aquaplaning speed until approximately 360 m of LDA remained (Figure 14).

Figure 14: Recorded groundspeed of VH‑SQY during landing

Source: Google Earth, annotated by the ATSB

Effect of reduced tyre tread

The ATSB reviewed research to assess the effect of reduced tyre tread on braking effectiveness when landing on a wet or contaminated runway. Research conducted by Leland & Taylor (1965) An investigation of the influence of aircraft tire-tread wear on wet‑runway braking concluded that:

On the wet runway, a gradual degradation in braking effectiveness was experienced up to about the 80 percent worn tire tread condition, where the wet-runway friction coefficients dropped markedly.

The completed worn tire was observed to develop, at higher speeds, only about one‑half the braking effectiveness of a new tire.

The research from O’Callaghan (2023) Wet‑runway overruns: still a slippery problem included consideration of the effect of tyre wear on braking performance and stated that:

For the aircraft operator, tire wear is a most important factor … the available 𝜇𝐵 [coefficient of braking] in wet conditions decreases as a tire wears. For a typical aircraft-type, rib-tread tire, when groove depths have been reduced to about 20% or less of the unworn value, the remaining tread may be ‘flattened out’ under load and the tire may then behave as if smooth

Additionally, the research paper Aircraft tyre hydroplaning and how to analyse it in runway excursion events, van Es (2018) discussed the effect of tyre tread on the depth of water required for aquaplaning to occur and stated:

The tyre tread grooves act similar to the pavement macrotexture in draining the bulk water. When there is sufficient macrotexture on the surface and/or the tyre has a sufficient number of deep circumferential grooves, full dynamic hydroplaning will normally not occur, unless the water depth is at a level that both tyre grooves and runway macro texture cannot drain the water sufficiently quick enough…

Smooth tread tyres operating on smooth pavements surfaces require the smallest fluid depth for dynamic hydroplaning, whereas rib treads tyres operating on an open textured or grooved-pavement surface require the largest fluid depths.

Related occurrences

Australia

The ATSB occurrence database contained 263 instances of runway excursions on landing in Australia between 2020‍–‍2024. The majority of these involved the aircraft veering off the runway rather than overrunning.

Of these occurrences, 3 included mention of standing water leading to aquaplaning, one of which involved a Cessna 525 operated by Air Link landing on runway 11C at Bankstown in 2022. The ATSB did not investigate these occurrences.

In 2020 the ATSB investigated the runway excursion of a Fokker 100 landing at Newman, Western Australia (AO‑2020‑002). It was found that poor braking effectiveness in wet conditions resulted in the aircraft overrunning the runway.

In 2008, the ATSB published a two‑part research report (AR‑2008‑018) titled Runway Excursions with the objective of analysing international and Australian trends in runway excursions. Part 1 of the report explored the contributing factors associated with runway excursions between 1998 and 2007. Water‑affected and contaminated runways was one of the contributing factors identified.

International

The ATSB identified the following occurrences of runway excursions associated with a wet or contaminated runway:

Runway excursion of a Beech 95-C55 on 12 January 2023 (NTSB WPR23LA089)

During the landing roll, the pilot applied the brakes but discovered that there was more standing water on the runway than expected, resulting in the airplane aquaplaning. It was determined that the wet runway contributed to the aircraft overrunning the runway.

Runway excursion of a Learjet 36 on 9 September 2022 (NTSB WPR22LA344)

During a landing following recent rainfall, the pilot reported that the aircraft did not decelerate normally and subsequently overran the runway. It was determined that a fast landing on a wet runway resulted in the airplane aquaplaning during the landing roll.

Safety analysis

Introduction

On the morning of 11 January 2025, a Cessna 510, registered VH‑SQY, was being used to conduct a medical air transport flight from Narrandera Airport to Bankstown Airport, New South Wales. During the landing at Bankstown, the pilot experienced reduced braking performance, and the aircraft overran the end of the runway.

This analysis will discuss the operator’s procedures for determining landing distance and the pilot’s use of these procedures. The environmental conditions at the time and the actions performed during the landing are also examined. Additionally, the analysis will consider the reporting of conditions at Bankstown Airport and the airport’s runway environment.

Pilot training

The pilot completed a type rating for the Cessna 510 with Air Link, a company related to the operator. The performance component of the ground school incorporated the use of Part 135 regulations. 

These regulations required the application of a 60% landing distance factor for a twin‑engine jet aircraft over 2,722 kg, such as the Cessna 510, when determining the landing distance required at a destination aerodrome. However, pilots were taught to use an 80% landing distance factor for this calculation. Use of this factor reduced the safety margin applied to mitigate issues that impacted the aircraft’s ability to achieve published landing performance. Furthermore, pilots were taught to use the aircraft flight manual (AFM) wet runway performance data for wet runway landing distances. However, this data was not permitted to be used for flight planning as it was from an advisory section of the AFM.

Operator procedures

Both the operator and the pilot reported that, consistent with the type rating training, a landing distance factor of 80% was used when determining the required landing distance. However, a 60% factor was required for these types of operations. 

The operator’s procedures contained guidance for calculating the required landing distance during the pre‑flight planning. However, while they referred to the application of specified factoring when determining landing distance available, they did not define what this factoring was. Additionally, the procedures did not advise that a landing distance assessment was required in‑flight in addition to prior to departure. 

Furthermore, the operator’s flight planning software provided 2 options for determining the landing distance required: 60% and 80% landing distance factors. However, the 80% option was incorrectly selected by default when using the APG iPreFlight App. In addition, an option to use the AFM advisory wet runway performance data was also available on the App. However, the operator’s guidance did not specify that this was not permitted to be used for flight planning.

Flight planning

Pre departure planning

Prior to departure, the pilot assessed the landing distance available at Bankstown Airport using tabulated data extracted from the flight planning software. Using the Terminal Area Forecast (TAF) at Bankstown Airport, they determined that the runway would likely be wet. While the TAF forecast a headwind on runway 11C, the pilot used a more conservative assumption of a 5 kt tailwind, despite the aircraft flight manual (AFM) stating that landing with a tailwind was not recommended on a wet runway.

The pilot used an 80% landing distance factor, as they had been taught, and determined that sufficient landing distance was available under these conditions. However, the use of a 60% factor was required for this flight.

The ATSB calculated the landing distance required using the conditions forecast in the TAF and the required 60% landing distance factor. It was determined that sufficient landing distance did exist at Bankstown due to the forecast headwind on runway 11C. Therefore, while incorrect data was used to conduct the assessment, the pilot correctly determined that a departure was possible.

In-flight planning

Prior to descent, the pilot obtained aerodrome conditions from the Automatic Terminal Information Service (ATIS). This information included that the wind was variable at 8 kt, the runway 11C was in use and the whole runway was wet. Using this information, the pilot again consulted the 80% landing distance factor tabulated data and determined that there was sufficient landing distance available to attempt a landing with up to a 10 kt tailwind. 

However, this assessment also required that a 60% factor was used. Use of this factor would have identified that insufficient landing distance was available to plan for a landing on runway 11C.

If the pilot had determined that insufficient landing distance was available to attempt the landing, options were available to hold for the weather to improve or request more up‑to‑date weather information from air traffic control (ATC).

Landing and runway excursion

Tyre condition

During the daily inspection of the aircraft, the pilot inspected the aircraft’s main landing gear (MLG) tyres and assessed them as serviceable. However, an inspection after the incident identified that the tyres were below the tyre manufacturer’s guidance for normal removal wear, and less than 10% of the tread was remaining.

Research showed that the braking performance of an aircraft on a wet runway degraded as its tyres wore, with a marked increase in effect when reaching 20% of the original tread depth. Additionally, the depth of tread on a tyre influenced the amount of standing water required to support aquaplaning. Consequently, while permitted for flight, the low tread on the aircraft’s MLG tyres likely had an adverse effect on the aircraft’s braking performance when landing on a wet or contaminated runway.

Meteorology

Rainfall and standing water

At Bankstown Airport there was a period of very heavy rain which continued until 1 minute prior to the landing. Given the intense nature of this rainfall, it is likely that parts of the runway were contaminated with standing water. Furthermore, video and photographic evidence showed that the aircraft encountered standing water during the landing roll. The pilot was not aware of the recent rainfall and had assessed the runway surface as wet but not contaminated, observing no standing water. This was consistent with the runway surface condition reported by the Automatic Terminal Information System (ATIS). Standing water on the runway provided an environment for aquaplaning. In addition, guidance material advised that when landing in very wet conditions degraded wheel braking may require an additional 30‍–‍40% of stopping distance.

Tailwind

The ATIS reported that the wind was variable at 8 kt. The pilot recalled that they considered this and had planned to use the reciprocal runway if they observed a tailwind greater than 5 kt. The pilot further reported that they did not observe, nor were they advised by air traffic control (ATC), of a tailwind. However, while the wind was initially a headwind during the approach, this headwind decreased and became a tailwind as the aircraft approached the runway and commenced the landing.

Landing with a tailwind increased the landing distance required. Additionally, while the recorded tailwind was below the maximum permitted by the aircraft flight manual (AFM), landing with any tailwind component was not recommended by the manufacturer when landing on a wet or contaminated runway.

Landing sequence

The aircraft conducted the final portion of the approach to an aim point short of the first touchdown marker. At 50 ft AGL, the indicated airspeed was within 5 kt of the V_REF and within the operator’s stabilised approach criteria. However, due to the tailwind encountered, the aircraft’s groundspeed was higher than the airspeed and above both the rotating and non‑rotating dynamic aquaplaning speeds during the touchdown. Consequently, the aircraft likely experienced dynamic aquaplaning when encountering standing water on the runway. Throughout the landing roll, the aircraft’s groundspeed did not decrease below the non‑rotating minimum aquaplaning speed of 72 kt until approximately 900 m into the landing roll.

During the landing roll, due to the lack of braking performance, the pilot elected to release and reapply the brakes and cycle the anti‑skid system. While well intentioned, this action likely further decreased braking performance as brake pressure was released for portions of the landing, and the anti‑skid system was momentarily not operational while a self‑test was conducted. Furthermore, this was not in accordance with the AFM which required that maximum braking was maintained throughout the landing roll. Damage observed on the main landing gear tyres was consistent with them having locked up under braking.

In summary, while the individual contributions of standing water, tailwind, tyre condition and pilot braking action could not be ascertained, the combination of these factors resulted in the aircraft’s reduced braking performance and subsequent runway excursion.

Bankstown Airport

Reported conditions

Wind and nominated runway

The ATIS reported the wind as variable at 8 kt with runway 11C nominated for use and no maximum tailwind advised. The Manual of Air Traffic Services (MATS) did not permit the nomination of a runway when there was a tailwind component with a wet runway. Recorded data showed that a mean tailwind had been recorded during the 6 minutes prior to landing. However, the wind direction was highly variable over this time. MATS required that ATIS information be updated when changes to meteorological conditions were expected to remain for 15 minutes, supporting the decision to report the wind as variable, and maintain runway 11C as the nominated runway. It was also required that wind significant to aircraft operation was provided to pilots with a landing clearance. However, at the time the landing clearance was given, the instantaneous wind observed by air traffic control (ATC) may not have indicated a tailwind.

Runway condition code

The ATIS reported the runway condition code as ‘whole runway wet’, however it was likely that sections of the runway were contaminated with standing water. Had the runway condition included sections reported as 2/standing water, the pilot would have been alerted to the potential for reduced braking performance.

However, ATC observations could only be used to declare a runway as fully dry or wet. Downgrading the runway surface condition required either 2 less-than-good braking reports from pilots or physical inspection of the runway surface by the aerodrome reporting officer (ARO). On this occasion, no braking reports had been received, and the ARO had not inspected the runway. After the incident, the ARO reported that there was no standing water observed. However, some water had likely drained away by this time.

Runway environment

Runway slope and drainage

Survey information showed that the longitudinal slope was approximately 0.15% up when landing on runway 11C. While the aerodrome manual and the aerodrome technical inspection (ATI) report contained conflicting information, Bankstown Airport advised that the surveyed slope was correct. 

The En Route Supplement Australia (ERSA) entry provided runway slope information expressed by dividing the runway into 3 sections and reporting the slope for each section individually. As a result, it was unclear how to use runway slope values for performance planning. However, as the reported slopes, and the actual surveyed slope were not greater than 0.5%, use of one or a combination of these values would have had little, if any, effect on landing distance calculations.

The ATSB was advised of previous discussions regarding poor runway drainage at Bankstown Airport. However, an aerodrome technical inspection had assessed that the drainage of the runway was operating effectively. In addition, the aerodrome manual stated that the runway slope was designed in accordance with regulatory requirements. Furthermore, while standing water was likely present during the landing, no standing water was observed by the ARO after the incident. Therefore, it was likely that the runway drainage was operating effectively.

Findings

From the evidence available, the following findings are made with respect to the runway excursion involving Cessna 510, VH-SQY, at Bankstown Airport, New South Wales, on 11 January 2025. 

Contributing factors

• During the approach, an undetected tailwind was encountered and the aircraft landed with a groundspeed higher than the minimum aquaplaning speed. In addition, there was likely standing water on the runway and the aircraft’s main landing gear tyres were worn to limits resulting in reduced braking performance. Subsequently, the pilot cycled the anti‑skid system, likely further decreasing braking performance. In combination, these factors resulted in the aircraft departing the end of the runway.
• The type rating training provided by Air Link taught pilots to apply an incorrect landing distance factor, which reduced the safety margin when determining the required landing distance at a destination aerodrome. (Safety Issue)
• AirMed required pilots to apply an incorrect landing distance factor, which reduced the safety margin when determining the required landing distance at a destination aerodrome. Furthermore, its procedures were unclear on how the factor should be applied, when the assessment should be conducted and how runway surface condition should be considered. (Safety Issue)
• When determining the required landing distance at Bankstown, the pilot applied the incorrect landing distance factor prescribed by the operator. Subsequently, prior to descent and after obtaining the actual conditions at the aerodrome, the pilot did not identify that the landing distance available was insufficient to attempt the landing.

Safety issues and actions

Type training

Safety issue number: AO-2025-002-SI-01

Safety issue description: The type rating training provided by Air Link taught pilots to apply an incorrect landing distance factor, which reduced the safety margin when determining the required landing distance at a destination aerodrome. 

Landing distance assessment procedure

Safety issue number: AO-2025-002-SI-02

Safety issue description: AirMed required pilots to apply an incorrect landing distance factor, which reduced the safety margin when determining the required landing distance at a destination aerodrome. Furthermore, its procedures were unclear on how the factor should be applied, when the assessment should be conducted and how runway surface condition should be considered.

Safety action not associated with an identified safety issue

Additional safety action by Air Link Pty Ltd

Air Link is in the process of including a new section in the endorsement training around wet weather operations, including the associated limitations and the effect of worn tyres on aircraft performance. In addition, it has implemented a policy of tyre replacement when tread reaches 2 mm, representing 80% wear.

Additional safety action by AirMed

The operator conducted the following additional proactive safety action:

• Provided training to all crew addressing the effects of tailwind, correct anti‑skid use, tyre limits and landing technique.
• Updated defect reporting procedures to encourage earlier reporting of anticipated maintenance requirements.
• Implemented a policy of tyre replacement when tread reaches 2 mm.

Safety action by Bankstown Airport

Bankstown Airport amended the runway 11C/29C longitudinal slope information in the aerodrome manual to align with the En Route Supplement Australia depiction of runway slope.

Safety action by the Civil Aviation Safety Authority

While not in response to this occurrence, the Civil Aviation Safety Authority subsequently amended the performance section of the Part 121 guidance material as part of its continuous improvement process. These changes included:

• the addition of a section specifying that landing performance must be checked both pre‑flight and in‑flight
• advice that actual landing distance data cannot be used to satisfy in-flight replanning operations
• provision of a list of known aircraft types, including the C510, that must not use actual landing distance data for in-flight landing distance calculations.

Glossary

Sources and submissions

Sources of information

The sources of information during the investigation included:

• the pilot and operator
• the manufacturer
• Air Link
• Bureau of Meteorology
• Civil Aviation Safety Authority
• Bankstown Airport
• Airservices Australia
• Aircraft Performance Group

References

Civil Aviation Safety Authority (2022). Aircraft flight manuals (advisory circular AC 21-34 v1.1), https://www.casa.gov.au/sites/default/files/2021-08/advisory-circular-21-34-aircraft-flight-manuals.pdf, CASA, accessed 1 April 2025.

Civil Aviation Safety Authority (2022). Guidelines for aeroplanes with MTOW not exceeding 5 700 kg - suitable places to take off and land (advisory circular AC 91-02 v1.2), https://www.casa.gov.au/guidelines-aeroplanes-mtow-not-exceeding-5-700-kg-suitable-places-take-and-land, CASA, accessed 8 May 2025.

O’Callaghan, J. (2023, August). Wet-runway overruns: still a slippery problem.  Presentation to the International Society of Air Safety Investigators (ISASI), Nashville, Tennessee, USA.

Van Es, G. (2018). Aircraft tyre hydroplaning and how to analyse it in runway excursion events. Presentation to the International Society of Air Safety Investigators (ISASI), Dubai, United Arab Emirates.

Leland, T. J., & Taylor, G. R. (1965). An investigation of the influence of aircraft tire-tread wear on wet-runway braking (Vol. 2770). National Aeronautics and Space Administration, Washington, D.C., USA

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:

• the pilot and operator
• the manufacturer
• Air Link
• Civil Aviation Safety Authority
• Bankstown Airport
• Airservices Australia
• Aircraft Performance Group
• National Transportation Safety Board.

Submissions were received from:

• the pilot
• the operator
• Air Link
• Bankstown Airport
• Civil Aviation Safety Authority.

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

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