An Australian Transport Safety Bureau (ATSB) investigation report into the 2018 crash of a VH-registered Bristell found that the pilot had performed manoeuvres classified as aerobatics in the moments before the crash.
Neither the pilot nor the aircraft were approved for aerobatics.
Bristell VH-YVX crashed near Stawell in October 2018 with two people on board after the aircraft couldn't be recovered from a spin. Both occupants sustained significant injuries.
Data recovered from the aircraft revealed that in the moments before the crash, the aircraft had been flown at bank angles up to 106 degrees right at less than 2000 feet above the ground. Such manoeuvres are considered aerobatic.
"Contrary to the aircraft’s limitations and the pilot’s qualifications, aerobatic manoeuvres were conducted during the flight, and immediately prior to the loss of control," the ATSB report states.
"The aircraft experienced an accelerated aerodynamic stall and entered into an upright, fully‑developed spin. Although the pilot did not consistently apply the manufacturer’s recommended spin recovery technique, recovery from a fully‑developed spin may not have been possible in the aircraft type."
The spin characteristics of the BRM Bristell have been under scrutiny following incidents where the aircraft has not recovered from a spin, including a fatal crash near Clyde, Victoria in 2017. CASA has since asked the manufacturer to provide evidence that the Bristell complies with ATSM standards for Light Sport Aircraft certification. Although BRM did provide test results, in March CASA moved to ban stall training in the type.
The ATSB investigation report also revealed that the aircraft had been flown in similar high angle-of-bank turns over Melbourne's south-western suburbs en route to Stawell, prompting the ATSB to issue a warning about aircraft limits.
" ... aerobatic flight should not be undertaken by pilots who are not been adequately trained, as it requires specialist techniques and methods to maintain control of the aircraft during significant manoeuvring," the ATSB stated.
"In addition, pilots need to be aware that when the aircraft manufacturers stipulate flight limitations and prohibit aerobatics in their aircraft types, this means the aircraft has not been designed or tested to ensure these manoeuvres can be done safely.
"Related warnings, advice and instructions need to be followed."
The full report is on the ATSB website.