A discrepancy in the training and guidance provided to the pilot of a Cessna Citation contributed to a runway overrun in wet conditions at Bankstown Airport, an ATSB investigation has found.
On 11 January 2025, the Citation Mustang light jet was conducting a medical transport flight from Narrandera to Bankstown, New South Wales, with a pilot, a flight nurse and a patient on board.
While landing on Bankstown's runway 11C, the pilot experienced reduced braking performance and the aircraft overran the end of the runway by about 30 m, coming to a rest in muddy ground. The occupants were uninjured, and the aircraft undamaged.
An investigation by the ATSB identified several factors contributed to the serious incident.
There was likely standing water on the runway, and the aircraft's main landing gear tyres were worn to limits. The aircraft had also encountered an undetected tailwind on approach, raising the groundspeed above the minimum aquaplaning speed.
Encountering braking issues during the landing, the pilot cycled the anti-skid system, which likely further decreased braking performance.
The investigation also found when determining the required landing distance at Bankstown, the pilot had applied an incorrect landing distance factor, which was prescribed by the operator, AirMed.
"AirMed required, and its associated type rating training provider Air Link taught, pilots to apply an 80% landing distance factor when determining the distance required at a destination aerodrome, rather than the 60% figure required in the relevant regulations," ATSB Chief Commissioner Angus Mitchell said.
"This reduced the safety margin when determining the required landing distance.
"Furthermore, AirMed's procedures were unclear on how the factor should be applied, when the assessment should be conducted, and how runway surface conditions should be considered."
In response, both AirMed and Air Link have updated relevant material to correct the landing distance factor. The operator also introduced the requirement to conduct a landing distance calculation both before take-off, and prior to landing.
In addition, while not directly relevant to the investigation's findings, Bankstown Airport has amended the runway 11C/29C longitudinal slope information in the aerodrome manual to align with the En Route Supplement Australia slope values, and the Civil Aviation Safety Authority has amended the performance section of the Part 121 guidance material as part of its continuous improvement process.
Mr Mitchell acknowledged the safety action taken by multiple parties since the incident.
"The use of safety margins on top of calculated take-off and landing distances provides mitigation for a wide range of issues that can impact performance, including unexpected environmental conditions," he said.
"As this occurrence demonstrates, there are limitations on accurate and timely reporting of runway surface condition - particularly after intense rainfall, given only 3 mm of standing water is required for a runway to be considered contaminated."
You can find here the final report: Runway excursion involving Cessna 510, VH-SQY, Bankstown Airport, New South Wales, on 11 January 2025
