What happened
On 17 May 1998, a Boeing 737-436, registration G-DOCD, was taxiing toward Stand N82 at London Heathrow Airport. The flight was operating as a public transport service. During the approach to the stand, the crew utilized the Azimuth Guidance Nose In Stands (AGNIS) system to assist with parking alignment.
As the aircraft maneuvered, the commander observed a catering truck positioned to the right of the stand, near the taxiway. While the body of the truck was close to the stand clearance lines, the pilot believed the vehicle's wheels were clear of the boundary. To complete a right-angled turn onto the stand, the aircraft's nose was positioned beyond the stand centerline. Because the AGNIS system indicated the aircraft was straight and on the centerline, the commander did not request that the co-pilot monitor the distance to the truck. During the maneuver, the right wingtip of the aircraft struck the catering truck, resulting in minor damage to the right wingtip and navigation light.