A twin-engine Cessna 441 Conquest collided with the ground shortly after take-off following a simulated engine failure at about 400 feet when the aircraft did not achieve the expected single-engine climb performance or target airspeed.
An ATSB investigation into the 30 May 2017 accident, near Renmark, South Australia, which resulted in the deaths of the three pilots on board, found the lack of expected performance was likely due to the method of simulating the engine failure, pilot control inputs or a combination of both. The investigation also established that normal power on both engines was not restored when the expected single engine performance and target airspeed were not attained.
“That was probably because the degraded aircraft performance, or the associated risk, were not recognised by the pilots occupying the control seats,” said ATSB Executive Director Transport Safety Nat Nagy.
“Consequently, about 40 seconds after commencing the simulated engine failure exercise, the aircraft experienced an asymmetric loss of control, and impacted the ground about four kilometres west of Renmark Airport.”
If one engine inoperative training sequences are conducted close to the ground, then effective risk controls need to be in place to prevent a loss of control, as recovery at low height will probably not be possible.
The aircraft, operated by Adelaide-based Rossair, was conducting a check flight on the Cessna 441 for Rossair’s chief pilot by a Civil Aviation Safety Authority (CASA) flight operations inspector (FOI). In turn, the chief pilot was conducting a check of an experienced Cessna 441 pilot who was rejoining Rossair after a period away from the company. The inductee pilot was the pilot flying and was seated in the aircraft’s front left control seat, the chief pilot was seated in the front right seat, and the CASA FOI was observing and assessing the flight from the first passenger seat directly behind the left-hand pilot seat.
They were operating a return flight from Adelaide Airport via Renmark, with a number of flight exercises planned as part of the inductee’s check flight, including the simulated engine failure after take-off on departure from Renmark.
“Conducting the engine failure exercise after the actual take-off meant that there was insufficient height to recover from the loss of control before the aircraft impacted the ground,” said Mr Nagy.
Noting that there is no Cessna Conquest simulator in Australia, the investigation highlights that one engine inoperative training should follow the manufacturer’s guidance and, where it is possible, be conducted in an aircraft simulator.
Mr Nagy said if one engine inoperative (OEI) training sequences are conducted close to the ground, then effective risk controls need to be in place to prevent a loss of control, as recovery at low height will probably not be possible.
“These risk controls can include defined OEI performance criteria that, if not met, require immediate restoration of normal power; use of the appropriate handling techniques to correctly simulate the engine failure and ensuring that aircraft drag is minimised/OEI performance is maximised; and ensuring that the involved pilots have the appropriate recency and skill to conduct the exercise and that any detrimental external factors, such as high workload or pressure, are minimised.”
The investigation also identified a number of safety factors, although they did not necessarily contribute to the accident flight. These included:
- The operator’s training and checking manual procedure for simulating an engine failure in a turboprop aircraft was inappropriate and increased the risk of asymmetric control loss;
- The CASA flying operations inspector was not in a control seat and was unable to share the headset system used by the inductee and chief pilot;
- The inductee and chief pilot, while meeting recency requirements, had limited recent experience in the Cessna 441;
- The chief pilot and other key operational managers within Rossair were experiencing high levels of workload and pressure; and
- CASA’s method of oversighting Rossair increased the risk that organisational issues would not be identified and addressed.
Mr Nagy also noted a lack of recorded data from the aircraft reduced the amount and type of evidence available to investigators about handling aspects and cockpit communications, as the aircraft was not fitted with a cockpit voice recorder or flight data recorder, and nor was it required to be.
“This limited the extent to which potential factors contributing to the accident could be analysed.”Last update 30 April 2020