What happened
On September 9, 2017, a Beechcraft King Air 250 was conducting a flight from LEPA to EPKT. While cruising at FL340 over Austria, the crew identified an uneven fuel consumption between the wing tanks. Upon realizing there was a potential leak, the crew notified Air Traffic Control (ATC) of the situation and the possibility of continuing the flight on a single engine.
As the fuel in the right wing was depleted, the crew proceeded to shut down and secure the non-functioning engine. The aircraft descended to FL240 to continue the flight using only the remaining operational engine. Following an assessment of the remaining fuel levels, the crew decided to divert to LKMT, where they performed an ILS approach to runway 2/22 and landed without further incident.
The investigation
The investigation focused on the source of the fuel imbalance and the crew's response to the leak. The investigation established that a faulty fuel valve located beneath the right engine nacelle was the source of the leak. Following the event, the operator replaced the damaged valve with a new component.
Findings
- The primary cause of the fuel leak during flight was a failure of the fuel valve.
- The crew waited until the fuel in the right wing was completely exhausted before shutting down the engine, rather than following emergency procedures which dictate shutting down the engine immediately upon detecting a leak.