Incident Overview
Description
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.
Primary Cause
Failure of the elevator pitch-up control cable due to wear on a cable to the right of a rope guide, exacerbated by a jet blast.Failure of the elevator pitch-up control cable due to wear on a cable to the right of a rope guide, exacerbated by a jet blast.Share on:
