Forty minutes after departing Cairns en-route to Japan, the
flight crew of the Boeing 747-300 aircraft noticed the number-5
left main entry door warning light illuminate. The flight engineer
investigated and found that the door handle had moved from its
fully locked 4-o'clock position to an unlocked 3-o'clock position.
The flight engineer, with the assistance of one of the cabin crew,
attempted to move the handle back to the fully locked position but
was unable to do so. Returning to the flight deck, a check of the
aircraft's technical logbook revealed that this problem had
occurred on previous occasions. The pilot in command contacted the
operator's maintenance headquarters, where he was advised that the
door would not be able to open due to the cabin being pressurised
and the flight could continue on to destination.
The cabin crew were advised to monitor the door for the rest of
the flight. Shortly before landing, the flight attendant seated
adjacent to the door observed the handle moving slowly upwards.
Just prior to touch down, the door handle jumped to the 2-o'clock
position at which time a loud wind noise could be heard. Leaving
his seat, the flight attendant grabbed the handle and forced it
down. Paper was observed being sucked under the door as the
passenger seated directly in front of the door (adjacent to the
window) turned and grabbed the door handle giving assistance in
pushing the handle down towards the locked position. The handle
reached the horizontal 3-o'clock position with the flight attendant
keeping weight on it until the aircraft had landed and taxied to
the terminal.
A minor adjustment of the door upper gate was carried out by
maintenance engineers before the aircraft's next departure. The
next two flights were uneventful, however on the third flight the
left main entry door-5 warning light again illuminated and the
handle moved from the fully locked to the unlocked, 3-o'clock
position. On arrival at the destination, an inspection by engineers
found the force required to move the door handle from the locked to
unlocked position was lower than required, necessitating further
adjustments to the door. An entry was also made in the aircraft's
technical log for a full rigging check and an inspection of the
door bearings to be carried out on the aircraft's return to its
main base. The aircraft then flew for two further flights, without
any reported defects, before returning to its main base.
Upon returning to the operator's main base, the door was removed
and disassembled for an inspection of the door bearings. No defects
were found and the door was returned to the aircraft where it was
refitted and a rigging check carried out. The aircraft was then
returned to service.
