Accident Overview
On 9 April 2003, a Robinson R44 helicopter, registration C-GRDI, departed on a local familiarization flight from the Trek Enterprises facility, approximately 10 nautical miles southeast of Peace River, Alberta. The pilot-in-command (PIC) was accompanied by the company's chief pilot designate (CPD), who was on board to acquaint himself with the pilot and the aircraft. The helicopter was substantially damaged, and both pilots sustained severe injuries to their lower extremities. There was no post-impact fire.
Sequence of Events
After a series of circuits, the helicopter was flown to the company's practice area where a number of practice autorotations with power-on recoveries were conducted. At least twice during these exercises, the engine rpm exceeded the prescribed limit. During the fourth autorotation, flown by the PIC, the airspeed and rotor rpm decreased to a point where the helicopter could not maintain flight and subsequently crashed into a treed area. The low rotor rpm horn had sounded, and the cyclic and collective controls began to move erratically. The CPD did not intervene, as he was unfamiliar with the helicopter and assumed the PIC had control.
Pilot Qualifications and Flight Details
The PIC held a valid commercial pilot license (helicopter) with endorsements on the R22 and R44, and had about 375 total flight hours, of which about 270 were on the R44. He had not flown an R44 since September 2002 and had recently completed 20 hours of training on a Bell 206, which has a high-inertia rotor system. The CPD held an airline transport pilot license (aeroplane) and a commercial helicopter license with endorsements on 10 helicopter types, but had no experience on the R44. His recent flying had been primarily fixed-wing; in the prior year, he had accumulated about 15 helicopter hours, none on the R44.
Contributing Factors
The helicopter's airspeed and rotor rpm were allowed to decrease to the point of uncontrollability, and the PIC did not recognize the critical flight condition nor apply timely corrective actions. The CPD was not qualified to fly the R44 and could not assume control when the PIC encountered difficulties. Both pilots had recent training on the Bell 206, a high-inertia rotor system, which differed significantly from the R44's low-inertia system. The PIC was aware of engine overspeed restrictions but continued the flight after the first overspeed.