On 14 January 2012 at approximately 0930 (local time), a ‘GT Kruza’ gyroplane (registration G-762) with a pilot and student passenger on-board, departed Mangalore Aerodrome, Victoria, for a one hour training flight. At around 1130 later that morning, a member of the public identified the wreckage of the gyroplane, which had impacted terrain a short distance from the aerodrome. Both occupants had sustained fatal injuries. There were no witnesses to the accident.
The Victorian Police Service was responsible for investigating this accident; assisted by investigators from the Australian Sports Rotorcraft Association (ASRA). From an assessment of the accident site, ASRA investigators determined that the gyroplane had impacted terrain at high speed with a near-vertical nose-down attitude. The rotor system had detached from the airframe during the impact sequence and lay several metres from the majority of the wreckage. There was no evidence of fire.
A preliminary inspection of the gyroplane’s flight controls found that the rotor head torque tube had fractured through the central section where it adjoined the rotor head torque bar. Upon closer examination, ASRA investigators identified evidence of possible pre-existing cracking within the torque bar at the point of failure, and in consideration of the critical nature of this component in the flight control system, ASRA staff sought assistance from the Australian Transport Safety Bureau (ATSB) in the formal technical examination and analysis of the torque bar failure. Assistance was also sought in the examination and possible data recovery from a GPS unit and personal mobile telephone being carried on board the gyroplane.
The following conclusions were drawn from the examinations performed:
- Fracture of the rotor head torque tube was directly associated with the development of fatigue cracking that had initiated from stress concentration effects around a clamping bolt hole that passed, by design, through the centre of the tube.
- The level of surface fretting and evidence of movement between the tube and torque bar suggested a level of inadequate clamping force between the components.
- There was no evidence of loosening of the clamping bolt locking nut.
- There was some evidence to suggest that the tightness/security of the clamping bolt nut had been checked at some time before the accident.
- No data was able to be recovered from either the Blackberry mobile phone or the Garmin GPSmap 295 device.
The investigation into the circumstances of this accident was conducted by the Victorian Police Service, supported by the Australian Sports Rotorcraft Association. The involvement of the Australian Transport Safety Bureau was limited to the technical examinations summarised within the associated report.
Requests for further information regarding the occurrence should be directed to the Victorian Police Service or ASRA.
|Date:||14 January 2012||Investigation status:||Completed|
|Investigation level:||Complex - click for an explanation of investigation levels|
|Location:||near Mangalore Airport, Victoria|
|State:||Victoria||Occurrence type:||Collision with terrain|
|Release date:||22 July 2013||Occurrence class:||Operational|
|Report status:||Final||Occurrence category:||Accident|
|Highest injury level:||Fatal|
|Aircraft manufacturer||GT Gyroplanes|
|Type of operation||Flying Training|
|Damage to aircraft||Destroyed|