Incident Overview
On 17 May 1998, at 1020 hours UTC, a Boeing 737-436, registration G-DOCD, was involved in a ground collision with a catering truck at London Heathrow Airport. The aircraft was manufactured in 1991 and powered by two CFM56-3C1 turbofan engines. The flight was a public transport operation with two crew members on board; the number of passengers was not known. No injuries were reported among the crew, and passenger injuries were not applicable. The impact resulted in minor damage to the right wingtip and navigation light.
Sequence of Events
The aircraft was taxiing onto stand N82 using the Azimuth Guidance Nose In Stands (AGNIS) system for parking alignment. As the aircraft approached the stand, the commander observed that the AGNIS was switched on and a catering truck was parked to the right of the stand, close to the taxiway. The commander judged that the truck's wheels were clear of the stand clearance white lines, though the truck's body was near them. During the turn onto the stand, the aircraft's nose was positioned beyond the stand centerline to execute the right-angled parking maneuver. The commander noted that the AGNIS indicated the aircraft was on the centerline and appeared straight; consequently, he did not ask the co-pilot to monitor the position of the truck. Before reaching the designated parking position, the right wing tip struck the truck.
Aftermath
After the collision, passengers disembarked normally down the steps following a delay. The commander later noted that the aircraft's nosewheel had been on the stand centerline but had skidded to the right as a result of the impact. The main wheels were offset to the right of the stand centerline, the fuselage was not aligned with the stand, and the right wing tip was slightly over the white clearance guide line.
Commander's Report
The commander reported that he had failed to monitor the wing tip clearance, relying entirely on the AGNIS system for guidance during the parking maneuver.