Incident Overview
Description
Cameroon Airlines flight 070 departed Douala for a flight to Paris via Yaound. The intermediate stop at Yaound was not made because of a severe delay (about five hours) in departure. The aircraft, named “Mont Cameroun”, climbed to cruising level FL350. The en route portion of the flight was uneventful. During the approach and landing two passengers were allowed on the flight deck and occupied the jumpseats. The final approach to runway 09R at the Charles de Gaulle Airport was flown at a speed of 160 knots. Flaps were selected at 30deg, the gear was extended and autopilot disengaged. The airplane touched down at a speed of 151 knots. After touchdown the captain selected reverse thrust. He then noted that the speedbrakes had not activated automatically, so he disarmed the autobraking system. About 1700 m down the runway the plane went off the right side. The 747 ran across a drainage ditch, causing the nose gear to be torn off. It appeared that the number one engine reverser was not activated and the engine was operating at full power. PROBABLE CAUSE: “The initial cause of the accident was the incomplete reduction of thrust on the left outer engine at the beginning of deceleration. This caused the de-activation of the automatic braking system and the non-extension of the nr.1 thrust reverser. The inadvertent selection of full thrust on this engine after the landing created a high thrust asymmetry leading to the runway excursion. The lack of co-ordination and of joint control by the crew members, perhaps aggravated by the presence of third parties in the cockpit, contributed to the development of this situation.”
Primary Cause
Premature reduction of thrust on the left outer engine during deceleration.Premature reduction of thrust on the left outer engine during deceleration.Share on:
