What happened
On 27 March 1999, during the loading process prior to departure at London Heathrow Airport, a Boeing 747-436, registration G-BNLL, sustained damage to its engine. While the aircraft was being prepared for a passenger flight, a baggage cart collided with the inboard cowling of the number one engine. The impact resulted in a split approximately 18 inches long in the cowling skin. The vehicle involved also sustained a small dent to the upper right corner of its cab.
The investigation
An initial inquiry conducted by the Airport Authority examined the circumstances surrounding the collision. The investigation established that the ramp environment was dry and weather conditions were sunny at the time of the incident. The baggage cart was inspected and found to be in proper working order, with no mechanical unserviceabilities identified that could have contributed to the event.
Investigators determined that the driver of the cart was aware of the standing instruction prohibiting driving between the engines of an aircraft, but chose to do so in an attempt to deliver the final pieces of luggage to hold 5 before the scheduled departure time.