The fatal crash of a Diamond DA40 in Queensland in has cast doubt over whether or not some aircraft are suitable for incipient spin training.
VH-MPM was on a simulated RPL test flight out of Archerfield in September 2017, when it crashed, killing both the student and the instructor.
According to the Australian Transport Safety Bureau (ATSB) investigation report released this week, the aircraft impacted the ground after it failed to recover from a developed spin, most likely the result of advanced stall training.
Radar data showed the aircraft conducted several short climbs followed by brief, rapid descents. On the final sequence, the aircraft climbed to 4500 feet after which it entered a near-vertical descent at about 6000 fpm.
The instructor was able to broadcast a Mayday call saying "the aircraft is in a sp ..." before it impacted the ground.
"On-site examination of the wreckage and surrounding ground marks indicated that the aircraft impacted terrain left wing first, nose-down and rotating to the left at low forward speed," the ATSB investigation found. "This was consistent with a left upright spin.
"The forward fuselage separated at the engine firewall. The wings, centre fuselage, and rear fuselage all separated in a direction consistent with a left spin."
The ATSB subsequently found that Diamond Aircraft does not approve the DA40 for intentional spins, either incipient or fully-developed, and that such action was outside the aircraft's approved envelope.
"Using rudder deflection to enter an incipient spin, even if the aircraft is immediately recovered from that incipient spin, is an intentional spin and therefore not allowed to be performed with a DA40," Diamond advised the ATSB.
The CASA syllabus for RPL training requires the student to demonstrate the ability to recognise and recover from an incipient spin.
During the investigation, the ATSB found that many flying training organisations did not consider that an incipient spin was included in the definition of intentional spinning as found in the Pilot's Operating Handbook of many training aircraft used in Australia.
"Operating an aircraft within the stated limitations is essential to the safe conduct of a flight," the ATSB said in a Safety Advisory Note. "Training organisations are required to conduct incipient spin recovery training, which includes intentionally inducing a spin and recovering before it fully develops.
"Some organisations may be conducting this training in aircraft not approved for intentional spinning. The ATSB advises these training organisations to clarify with aircraft manufacturers the extent to which the intentional entry into the early stages of a spin, including an incipient spin, is permissible."
The full investigation report and Safety Advisory Note are on the ATSB website.