What happened
On August 9, 2007, an Air Moorea DHC6-300, registration F-OIQI, departed Moorea for a routine short-haul flight to Tahiti Faa’a. The aircraft was carrying one pilot and 19 passengers. The flight was operating under VFR conditions with a planned cruise altitude of 600 feet.
Following a normal takeoff, the aircraft climbed to an estimated altitude of between 300 and 400 feet. At approximately 22:01:07 UTC, the pilot reduced the propeller RPM in accordance with standard operating procedures. Seconds later, the pilot expressed surprise, and the aircraft's Ground Proximity Warning System (GPWS) triggered multiple consecutive alarms. The aircraft entered a sudden, steep dive, striking the water approximately 700 meters from the shoreline. The impact caused the aircraft to disintegrate. Of the 20 people on board, 14 fatalities were recorded, while 6 passengers survived.
The investigation
The BEA investigation focused on the flight sequence, the aircraft's mechanical condition, and the wreckage recovered from a depth of 700 meters. Investigators analyzed the Cockpit Voice Recorder (CVR) and examined the aircraft's maintenance history, noting that the engines had been recently replaced.
Technical examinations of the wreckage revealed significant wear on the rear sections of the elevator control cables. Specifically, the rear pull cable was found to be broken at a point where it had been subject to heavy wear due to contact with a cable guide. Re-enactment flights demonstrated that retracting the flaps on this aircraft type created a strong pitching moment, and without significant manual elevator input to compensate, the descent rate could rapidly reach 3,000 feet per minute.
Findings
- The aircraft experienced a sudden loss of control during the transition from takeoff to normal climb.
- The rupture of the elevator control cable was identified as a critical factor in the loss of longitudinal control.
- The retraction of the flaps induced a heavy nose-down pitching moment that the pilot was unable to counteract following the cable failure.