From IFALPA Daily News Service
Dislodged lock-pin led to Lufthansa 747 nose-gear collapse
David Kaminski-Morrow, London (01Jun06, 15:16 GMT, 222 words)
German investigators have discovered that the nose-gear door of a Lufthansa Boeing 747-400 dislodged a locking pin during a hydraulic test, causing the gear to retract while the aircraft was parked at a Frankfurt Main gate.
The nose-gear retracted while the aircraft was preparing for pushback at Frankfurt, ahead of operating a service to Delhi, on 15 May. The 747’s nose settled onto the pushback tractor and the jet’s forward fuselage underside suffered heavy damage.
Preliminary examination of the aircraft by German investigation agency BFU has revealed that the aircraft was undergoing a test of its hydraulic system following indications of a leak.
As part of the test a locking pin was inserted into the nose-gear strut to prevent retraction while the landing-gear retraction mechanism was activated from the cockpit.
But a spokesman for BFU says that the movement of the nose-gear doors led to the pin’s becoming “disconnected” from its position. While the pin remained intact, he says, it was no longer able to prevent the nose wheels from retracting.
BFU is studying the design of the pin which, says the spokesman, had not been supplied by Boeing but which had been specially-made.
Boeing is to assess the damage to the aircraft, a five-year old example registered D-ABTK. There are no indications as to when the 747 might return to service.
Source: Air Transport Intelligence news