What happened
On 15 January 2001, a Boeing 747-4H6, registration 9M-MPH, arrived at London Heathrow Airport from a long-haul flight. The aircraft was scheduled to park at Stand J2 within Terminal 3. Prior to the aircraft's arrival, a ground handling agent had positioned three tugs and several baggage dollies near the stand.
A ramp supervisor performed a safety check before the aircraft arrived. While the supervisor noted a high loader vehicle was positioned too close to the stand, they judged the tugs and dollies to be at a safe distance from the stand centreline. The supervisor subsequently activated the Automatic Positioning and Information System (APIS).
As the aircraft taxied into the stand, the commander observed the APIS was active and noted the presence of the parked ground equipment. The pilot judged there was sufficient clearance and continued following the guidance. However, as the aircraft approached its final parking position, the number four engine struck one of the tugs. The impact pushed the tug into the other pieces of equipment, causing one tug to tip onto its side and become wedged under the engine nacelle. The collision resulted in damage to the number four engine nose cowl, fan cowl, and the right reverser sleeve. There were no injuries to the 22 crew members or 367 passengers on board.
The investigation
The investigation examined the ground handling procedures, the configuration of the parking stand, and the visibility of surface markings. Investigators found that the tugs and dollies had been left unattended on the stand. Furthermore, the investigation looked into the effectiveness of the emergency stop procedures and the clarity of the airport's multi-choice apron markings.
Findings
- The primary cause of the accident was a breakdown in ground handling procedures and errors in judging the clearance of the parked equipment.
- Ground vehicles were left unattended on the stand in violation of safety regulations.
- The APIS was activated before a complete safety check of the stand was confirmed.
- The white parallel lines used to indicate wing span limits at the stand were not distinctive and could be easily misinterpreted.
- Current procedures did not require ground personnel to be within immediate range of the emergency stop button during the aircraft's arrival.
- There was evidence of inconsistent compliance with ground handling instructions among ramp personnel.