What happened
On 4 March 2004, a Boeing 737-78J, registration YR-BGF, arrived at London Heathrow Airport from Bucharest. While taxiing to Stand 214 for passenger disembarkation, the flightcrew attempted to park the aircraft using the AGNIS lateral guidance system and mirrors. At the time, the crew and groundpersonnel were unaware that the specific stand required a marshaller for aircraft of this type.
As the commander taxied forward, he used mirrors to monitor the nosewheel position. However, a parked aircraft tug was obstructing the view of the primary stop mark in the lower mirror. The commander instead identified a different marking—the end of the centerline—and used this as his intended stopping point. Although groundcrew activated the emergency stop light, the signal was not visible to the pilot. The aircraft continued forward until the upper part of the No 1 engine cowling made contact with the stand jetty, causing damage to the cowling.