What happened
On 26 August 2005, a Robinson R2-2 Beta, registration G-CBPT, was conducting a private sightseeing flight near Cowes, Isle of Wight. The pilot, who had been practicing maneuvers earlier that day, was flying toward a private landing site. While maneuvering north of Cowes, the pilot heard a loud bang and experienced a sudden loss of control. The helicopter immediately entered an autorotation.
Recognizing that a ditching was unavoidable, the pilot instructed the passenger to loosen their seatbelt and unlatch the cabin door. The pilot successfully executed a controlled touchdown alongside the Prince Consort Buoy at the entrance to Cowes Harbour. Although the helicopter filled with water and sank quickly, both occupants were able to exit the aircraft unaided and were rescued by nearby boats. There were no fatalities and no injuries.
The investigation
Investigators examined the aircraft's technical history and the circumstances of the mechanical failure. The pilot noted several unusual symptoms prior to the accident, including a delayed rotor start during the morning's training session and a clutch warning light that illuminated multiple times. During the flight, the pilot also reported hearing whining noises.
Technical analysis focused on the drive belts transmitting power from the engine to the main transmission. While no wreckage was recovered from the seabed, the symptoms reported by the pilot were consistent with the failure of one of these belts. The investigation also noted that the aircraft was equipped with lap and inertia-reel shoulder harnesses, and while the pilot's decision to unlatch the doors was considered prudent, neither occupant was wearing a lifejacket.
Findings
- The primary cause of the loss of power was the failure of one of the two drive belts connecting the engine to the main transmission.
- The pilot's decision to unlatch the doors prior to touchdown facilitated a rapid exit by equalizing pressure.
- The aircraft's engine and fuel levels were sufficient for the flight, with no evidence of fuel exhaustion.
Safety action
- A safety recommendation has been made regarding the provision of advice to pilots concerning ditching procedures.