An investigation report released today into the fatal crash of a Cessna 441 near Remark, SA, in 2017 has identified a failure to maintain speed and subsequent loss of control as causes.
Three pilots died in Rossair Conquest VH-XMJ in May 2017 after it crashed during a simulated engine failure after take-off (EFATO) exercise. On board the aircraft were a pilot undergoing a check flight, the company Chief Pilot (CP) and a CASA Flying Operations Inspector (FOI) checking the CP.
According to the Australian Transport Safety Bureau (ATSB), the aircraft speed decayed below the minimum control speed (Vmca) and control was lost at an altitude that allowed no time for recovery.
"The ATSB determined that, following a simulated failure of one of the aircraft’s engines at about 400 ft above the ground during the take-off from Renmark, the aircraft did not achieve the expected single engine climb performance or target airspeed," the report states.
"As there were no technical defects identified, it is likely that the reduced aircraft performance was due to the method of simulating the engine failure, pilot control inputs or a combination of both.
"It was also identified that normal power on both engines was not restored when the expected single engine performance and target airspeed were not attained."
The ATSB report also notes that the aircraft operating handbook recommends that EFATO exercises be conducted at an altitude of no less than 5000 feet. They also determined that the method of simulating the failure may have actually increased the Vmca, which contributed to the pilots losing control at a speed higher than expected.
"Although a lack of recorded information prevented identification of the precise reason/s that the aircraft failed to achieve the expected OEI performance, the ATSB concluded that the method of simulating the power loss and pilot control inputs, together or in isolation, probably increased the actual VMCA significantly above the published value of 91 kt," the investigation report states.
"The aircraft then experienced an asymmetric loss of control when the airspeed reduced below that minimum control speed. The near-vertical impact signature was consistent with that loss of control mechanism.
"The ATSB also considered the potential that the loss of control was the result of an aerodynamic stall. However, given that the final recorded indicated airspeed was about 20 kt higher than the aircraft’s stall speed that was considered unlikely."
Other contributing factors that the ATSB believes increased the risk of the EFATO exercise included:
- The operator's training and checking manual procedure for a simulated engine failure in a turbo-prop aircraft was inappropriate and, if followed, increased the risk of asymmetric control
- The FOI was not in a control seat and did not share a communication systems with the crew. Consequently, he had reduced ability to actively monitor the flight and communicate any identified performance degradation.
- The inductee pilot had limited recent experience in the Cessna 441, and the CP had an extended time period between being training and being tested as a check pilot on this aircraft. While both pilots performed the same exercise during a practice flight the week before, it is probable that these two factors led to a degradation in the skills required to safely perform and monitor the simulated engine failure exercise.
- The CP and other key operational managers within Rossair were experiencing high levels of workload and pressure during the months leading up to the accident.
The full investigation report is on the ATSB website.