Meteorological conditions and pre-flight preparation are among the areas of focus in the ATSB's ongoing investigation into the fatal collision with terrain of an amateur-built Wittman Tailwind light aircraft on 12 January.
The ATSB's preliminary report details that the aircraft, registered VH-TWQ, had departed Evans Head, NSW, bound for Boonah, Queensland, with the pilot and one passenger on board, operating under visual flight rules (VFR).
The report notes the aircraft flew in a north-westerly direction towards Boonah before commencing a 180 degree turn overhead the township of Kyogle and diverting to the south to Casino. After about 45 minutes on the ground, the aircraft departed Casino to continue the flight to Boonah.
Approximately 15 minutes later, the aircraft was flying over the Tooloom National Park when recorded data shows it commenced a left turn before shortly afterwards colliding with terrain. The pilot and passenger were fatally injured and the aircraft was destroyed.
Due to the damage to the airframe, the aircraft's attitude when it entered the tree canopy could not be determined.
Subsequent examination of the wreckage by ATSB transport safety investigators indicated that the aircraft collided with a number of trees before coming to rest on the rainforest floor. The aircraft's structure was substantially disrupted, with the wreckage trail covering a length of about 120 metres.
"The ATSB's ongoing investigation will include examination of the meteorological conditions and pre-flight preparation," said ATSB Director Transport Safety Stuart Macleod. "Investigators will also examine the recovered wreckage, the aircraft's performance characteristics and recorded flight data, and analyse the pilot's qualifications and experience and the aircraft's maintenance documentation and operational records."
Mr Macleod stressed that this investigation is still in its early stages, and the ATSB will not publish its findings until the final investigation report is released.
"However, the ATSB does note that meteorological conditions and preflight planning are areas of focus for this investigation, and weather-related general aviation accidents remain one of the ATSB's most significant causes for concern in aviation safety."
To reinforce to visual flight rules pilots the dangers of flying into instrument meteorological conditions - IMC, and to highlight the actions they can take to avoid a weather-related accident, the ATSB has developed a safety promotion campaign titled 'Don't push it, DON'T GO - Know your limits before flight'.
"'Don't push it, DON'T GO' highlights three key messages: the importance of thorough pre-flight planning and having alternate plans, that pressing on where there is the possibility of entering IMC carries a significant risk of spatial disorientation, and the value of using a 'personal minimums' checklist to help manage flight risks," Mr Macleod said.
Flying into poor weather without the training and experience to do so can rapidly lead to spatial disorientation when the pilot cannot see the horizon.
"The brain receives conflicting or ambiguous information from the sensory systems, resulting in a state of confusion that can rapidly lead to incorrect control inputs and a resultant loss of control of the aircraft," Mr Macleod noted.
"For pilots who fly under VFR, conducting thorough preflight planning and working to a personal minimums checklist aids sound decision-making both prior to take-off and during flight when faced with marginal weather or darkness."
Findings from ATSB investigations into aircraft accidents where a VFR pilot flew into IMC are published in the ATSB's recently updated Accidents involving pilots in Instrument Meteorological Conditions publication, re-released as part of the Don't push it, DON'T GO campaign.
You can find here the preliminary report AO-2020-004: Collision with terrain involving Wittman Tailwind, VH-TWQ, Tooloom National Park, NSW, on 12 January 2020
