Accident to the DHC6 – 300 off the coast of the island of Moorea (French Polynesia) on 9 August 2007
Press release, 4 December 2008
The BEA has completed its investigation into the accident that occurred on 9 August 2007 off the coast of Moorea (French Polynesia) to the Twin Otter, registered F?OIQI, operated by Air Moorea.
The conclusions of the investigation were presented to the families of the victims and to the press on 3 December 2008 at Papeete. The final report is available on the BEA's website.
The accident occurred after takeoff, at the time of flap retraction. The pilot lost control of the airplane, which dived down and struck the surface of the water.
The investigation confirmed that the aircraft's loss of pitch control resulted from the failure of the elevator pitch-up control cable. This stainless steel cable was made up of seven strands. Tests and research undertaken by the BEA showed that the cable failure was due to a chain of events involving the following three phenomena:
- Significant wear affecting the six outer strands of the cable;
- An on-the-ground failure of several strands, likely on the apron under the effect of jet blast from a heavy aircraft;
- In-flight failure of the last strands due to the loads exerted on the elevator control when the flaps were retracted.
The BEA also identified five probable contributory causes:
- The absence of information and training for pilots on the loss of pitch control;
- The operator's omission of special inspections;
- The failure by the manufacturer and the aviation authorities to fully take into account the wear phenomenon;
- The failure by the airworthiness authorities, airport authorities and operators to fully take into account the risks associated with jet blast;
- The rules for replacement of stainless steel cables on a calendar basis, without taking into account the activity of the airplane in relation to its type of operation.
In addition to the two recommendations issued on 9 October 2007, the report contains six safety recommendations, the most notable being a ban on stainless steel control cables on DHC6 airplanes and improving awareness of aerodrome and aircraft operators of the effects associated with airplane jet blast.