Loss of control Accident de Havilland Canada DHC-6 Twin Otter 300 F-OIQI,

ASN Wikibase Occurrence # 321904

Date:	Thursday 9 August 2007
Time:	12:01
Type:	de Havilland Canada DHC-6 Twin Otter 300
Owner/operator:	Air Moorea
Registration:	F-OIQI
MSN:	608
Year of manufacture:	1979
Total airframe hrs:	30833 hours
Cycles:	55044 flights
Engine model:	Pratt & Whitney Canada PT6A-27
Fatalities:	Fatalities: 20 / Occupants: 20
Aircraft damage:	Destroyed, written off
Category:	Accident
Location:	1,5 km off Moorea-Temae Airport (MOZ) - French Polynesia
Phase:	Initial climb
Nature:	Passenger - Scheduled
Departure airport:	Moorea-Temae Airport (MOZ/NTTM)
Destination airport:	Papeete-Faaa Airport (PPT/NTAA)
Investigating agency:	BEA
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
A DHC-6 Twin Otter operated by Air Moorea as flight 1121, departed Moorea-Temae Airport in French Polynesia.
After a normal takeoff, the flaps were retracted at around 350 feet. The pilot then lost pitch control of the aeroplane, which adopted a steep nose-down attitude. The pilot was unable to regain control of the aircraft and the Twin Otter struck the sea, broke up and sank.

The accident was caused by the loss of airplane pitch control following the failure, at low height, of the elevator pitch-up control cable at the time the flaps were retracted.
This failure was due to a sequence of the following:
- Large wear of a cable to the right of a rope guide;
- External phenomenon, probably jet blast, causing the rupture of several strands;
- Failure of the last strands as a result of strain during the flight when using the elevator.

The following factors contributed to the accident:
- 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 aviation authorities, airport authorities and operators risk 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.

Accident investigation: