What happened
On September 2, 2007, an Agusta Bell AB 206 A, registration OO-ACR, was operating a private flight in Desteldonck, Belgium. The aircraft had been hired to provide several short flights for guests at a party. Following a series of successful maneuvers, the pilot prepared to return to the home base in Wichelen.
While the engine was at idle, the pilot made a telephone call to announce the return. During this period, the pilot set the cyclic controls to a neutral position and applied the friction brake. As the pilot initiated the takeoff by applying full throttle and collective, the helicopter began to move toward the rear. The rear portion of the right-hand skid dug into the rough ground, creating a pivot point. This triggered a dynamic rollover, causing the aircraft to tilt to the right and crash.
The investigation
The investigation focused on the sequence of events during the takeoff phase and the state of the aircraft controls. Investigators examined the wreckage and determined that the helicopter's engine had been operating normally prior to the impact. The investigation also reviewed the pilot's credentials and the aircraft's maintenance history, finding that the Agusta Bell AB 206 A was technically airworthy and the pilot held a valid license.
Findings
- The primary cause of the accident was a dynamic rollover caused by the aircraft being caught off-balance during liftoff.
- The pilot had applied the friction brake with the cyclic controls in a position that did not account for the helicopter's tendency to translate backward.
- As power was increased, the rear of the right-hand skid became embedded in the ground, acting as a fulcrum.
- The terrain at the takeoff site was flat but rough, contributing to the skid catching the ground.
- The aircraft sustained severe damage, including a deformed airframe and a separated main rotor transmission; one rotor blade broke upon impact and struck a nearby hangar.