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.
Local safety action
As a result of this incident, the operator reported that it has reviewed the door rigging procedures and determined that, `if a door-rigging defect has occurred then a full door rigging procedure should be carried out in accordance with the maintenance manual and scheduled in a `Heavy Maintenance' environment'.
|Date:||02 April 2002||Investigation status:||Completed|
|Time:||0910 hours UTC|
|Location:||741 km N Cairns, Aero.|
|Release date:||21 October 2002|
|Report status:||Final||Occurrence category:||Incident|
|Highest injury level:||None|
|Aircraft manufacturer||The Boeing Company|
|Type of operation||Air Transport High Capacity|
|Damage to aircraft||Nil|
|Departure point||Cairns, QLD|
|Departure time||1730 hours UTC|