What happened
On 30 January 1998, a SA341G Gazelle 1, registration G-PYOB, was conducting a private flight from Sittingbourne, Kent, via Rochester to Battersea Heliport. During the approach from the east, air traffic controllers and ground personnel observed a liquid spray emanating from the underside of the aircraft. It was quickly identified as fuel leaking from the fuel tank area.
Upon noticing the leak, the controller informed the pilot that the fuel cap was hanging down the side of the tank and advised an immediate landing and engine shutdown. The pilot proceeded to the originally assigned landing spot, spot 4, before shutting down the engine. While the passenger evacuated the aircraft immediately, the pilot remained to inspect the exterior and replaced the fuel cap before disembarking.
The investigation
The investigation examined the circumstances surrounding the fuel leak and the aircraft's recent maintenance and refueling history. It was noted that during a refueling stop at Rochester prior to the incident, the tanker driver had alerted the pilot that the fuel cap appeared worn and was not fitting correctly. The pilot had dismissed these concerns, stating that the cap simply required tightening past the red alignment marks.
Following the landing, a pool of fuel had formed beneath the aircraft. The heliport fire crew applied a foam blanket as a precaution, and the local fire service arrived with three appliances to monitor the aircraft while the engine cooled. Once the fire risk had subsided, crews flushed the fuel residue from the engine and tank areas and cleaned the parking surface.
Findings
- The leak was caused by a fuel cap that was not properly secured or was functionally defective.
- The pilot had been warned by a refueling technician that the cap was worn and not seating correctly, but chose to continue the flight.
- There were no injuries to the crew or passenger, and no damage was sustained by the aircraft.