What happened
On August 5, 2005, at approximately 16:22 UTC, a Robinson R22 Beta helicopter was performing a training autorotation at the Spitzerberg airfield in Hundsheim, Lower Austria. During the landing maneuver, the rotor RPM was too low to effectively reduce the rate of descent.
As the aircraft made its initial contact with the ground, the impact force heavily loaded the landing skids and their attachments, causing elastic and plastic deformation. This impact caused the helicopter to bounce several meters above the ground. Immediately following this bounce, the aircraft made a second, much harder impact with the ground. Because the airframe lacked a structure capable of absorbing the energy of this second strike, the occupants sustained severe injuries.
The investigation
The investigation, conducted by the Federal Safety Investigation Office (SUB), reconstructed the sequence of events using eyewitness testimony and field examinations. The investigation focused on the flight phase of the autorotation and the mechanical state of the aircraft at the time of the landing.
Findings
- The primary cause of the accident was insufficient rotor RPM during the landing maneuver, which prevented the pilot from damping the descent rate.
- The initial impact caused the landing gear to deform and triggered a secondary, high-energy impact.
- The aircraft sustained two fatalities (one crew member and one passenger) due to the severity of the second impact.
- The Robinson R22 Beta was destroyed in the accident.
- A technical examination of the aircraft revealed no evidence of pre-existing mechanical defects.