What happened
On 14 November 2001, an Airbus A320-232, registration G-MIDY, was undergoing refuelling at London Heathrow Airport as part of a public transport operation. Following the completion of the refuelling process using a hydrant vehicle, the refueller drove the vehicle away from the aircraft without disconnecting the nozzle. The driver did not realize the equipment was still attached until reaching the refuelling company's parking area, roughly one mile from the aircraft.
The incident resulted in a broken refuelling adapter ring on the aircraft. While the damage rendered the aircraft unserviceable, no fuel was released during the event. The aircraft was repaired and returned to service the next day.
The investigation
The investigation was based on the aircraft accident report submitted by the pilot and interviews conducted with the refueller. The inquiry focused on the refuelling organisation's internal investigation, which found that the refueller had failed to follow the vehicle's checklist and the company's Operations Manual, specifically regarding the verification that all hoses were secure before departing.
Investigators examined the refuelling vehicle's interlock system, which is designed to prevent the engine from starting unless all nozzles are properly stowed. It was discovered that the interlock for the aircraft nozzle was non-functional due to a bent actuating rod. This mechanical fault caused the system to provide a false positive, indicating that the nozzle was correctly stowed even when it was not. Although the system had been recorded as serviceable during the previous weekly inspection, the defect had rendered the safety mechanism ineffective.
Findings
- The refueller was distracted by an unexpected paperwork issue during his routine, leading him to believe the hoses had been disconnected.
- The refuelling vehicle's interlock system was unserviceable due to a bent actuating rod, which falsely indicated that the nozzle was stowed.
- The refueller did not adhere to the required checklists or operational procedures for securing hoses before driving the vehicle.