The ATSB has released a preliminary report to detail factual information established as part of its ongoing investigation into an accident involving a Cirrus SR22 light aircraft near Gundaroo, north of Canberra on 6 October 2023.
The report, which does not outline findings nor provide analysis, details that the aircraft had departed Canberra bound for Armidale with a pilot and three passengers on board shortly after 2:30pm, with the pilot operating under the instrument flight rules.
Data from the aircraft's ADS-B (Automatic Dependent Surveillance Broadcast) transmitter, which broadcasts GPS-derived position and speed information, shows that as it climbed through 7,500 ft up to its planned cruising altitude of 10,000 ft its groundspeed fluctuated and its track varied.
Several people at locations below the aircraft's flight path during this time reported hearing noises that they described as a rough running or surging light aircraft engine.
"Twelve minutes after take-off, the aircraft was about 25 km north of Canberra, at an altitude of about 10,000 ft, when it abruptly departed from controlled flight and descended steeply towards the ground. Witnesses described the aircraft rotating in a corkscrew motion," said ATSB Director Transport Safety Kerri Hughes.
The aircraft collided with the ground on a private property in an open field adjacent to a dam. The occupants were fatally injured, and the aircraft was destroyed by a post-impact fire.
"Impact marks and wreckage distribution at the accident site indicated that the aircraft impacted with terrain upright, with a slight nose low attitude and with little forward momentum, suggestive of a spin," said Ms Hughes.
"Key components of the aircraft's airframe parachute system were all located within the wreckage, However, based on the available evidence, the ATSB was unable to determine if an attempt had been made by the pilot to deploy the parachute system before the impact."
Damage to the propeller blades indicated that the engine had low or no power at impact. The report notes that spin recovery, icing, un-porting of fuel tank outlets in a spin, preparation for use of the parachute, and an engine mechanical issue could all be reasons for a power reduction.
The forecast meteorological conditions at the time of the accident included isolated rain showers, broken cumulus/stratocumulus cloud, and a freezing level of 5,000 ft in the south and 8,000 ft in the north, conditions which can imply moderate turbulence and moderate icing.
"As the investigation continues, the ATSB will continue an assessment of the recovered components, review pilot and operator documentation and pilot medical information, and analysis of the aircraft's performance based on flight track data and meteorological information," said Ms Hughes.
The ATSB will release a final report, detailing contributing factors and analysis, at the conclusion of the investigation.
"However, if at any stage we identify a critical safety issue, we will immediately alert the relevant parties so that they might take safety actions."
You can find here the report: Collision with terrain involving Cirrus SR22, VH-MSF near Gundaroo, NSW on 6 October 2023
