What happened
On May 31, 2010, a Robinson R22 helicopter, registration F-ORGB, was performing a local flight near the Col des Bœufs in Réunion Island. The pilot had arrived at the landing site to collect packages and intended to transport passengers to a nearby forest house. To save time, the pilot opted for a running rotor boarding procedure.
After the first passenger boarded while the engine was running, the pilot initiated a takeoff. The aircraft lifted approximately one meter, then moved backward and turned right into a slope. During this maneuver, the tail rotor struck the terrain, and the right skid became wedged under a rock. The helicopter subsequently crashed, resulting in two fatalities (the pilot and the passenger).
The investigation
The investigation focused on the sequence of events during the boarding and takeoff phases, as well as the mechanical state of the aircraft. Investigators examined the wreckage and found that the engine was no longer producing power at the time of impact. Notably, the carburetor contained almost no fuel, and the fuel valve was found in a position nearly closed.
Testing was conducted on a similar Robinson R2/2 to evaluate the ergonomics of the fuel valve. The aircraft was equipped with an older model valve featuring a handle rather than a modern selector. The tests demonstrated that a passenger, while bracing themselves or securing a seatbelt during boarding, could inadvertently grasp and turn the handle toward the 'OFF' position. Furthermore, the aircraft lacked a cockpit indicator to show the exact position of the valve, leaving the pilot dependent solely on the fuel pressure gauge.
Findings
- The primary cause of the accident was the engine failure during takeoff caused by the accidental closure of the fuel valve by the passenger during the running rotor boarding process.
- The use of an older-style fuel valve without a safety guard or a secure selector made accidental manipulation possible.
- The decision to perform a rapid takeoff following a running rotor boarding without conducting specific pre-takeoff checks contributed to the lack of detection of the fuel starvation.
- The topographical constraints of the landing site provided no margin for error or an alternative landing solution in the event of an engine failure.