What happened
On February 9, 2005, a Piper PA-23-250, registration OE-FFY, operated by NÖFSC, was conducting an IFR flight from Odense, Denmark, to Vienna, Austria. During the flight within the Prague FIR, the pilot was initially permitted to fly under VFR due to an inability to tune specific radio frequencies.
At approximately 11:23 UTC, the pilot notified Prague FIC controllers that a smell of fuel was present in the cockpit and expressed concern regarding a potential engine issue. The pilot requested a diversion to Prague/Ruzyně (LKPR). Upon contacting Prague Tower, the pilot reported that fuel was leaking from the right wing and that the aircraft might arrive with the right engine inoperative.
The aircraft landed on runway 2 and was met by airport rescue and fire services. Upon inspection at the parking stand, no active fuel leak was detected, and the aircraft showed no signs of fire.
The investigation
The ÚZPLN investigation examined the pilot's actions, the aircraft's technical condition, and the fuel system configuration. The investigation reviewed maintenance records, which showed that a recent inspection by Diamond Maintenance GmbH&CoKG had found no leaks in the fuel system. The investigation also analyzed the fuel levels upon landing, noting a significant depletion in the right wing tanks compared to the left wing tanks.
Investigators also looked into the pilot's radio communications, noting that the pilot was unable to tune certain frequencies due to a lack of familiarity with the radio equipment's operation.
Findings
- The pilot possessed the necessary qualifications and valid medical certification.
- The aircraft was airworthy with valid maintenance and insurance.
- The smell of fuel in the cabin was likely caused by the cabin heating system rather than an external leak.
- The depletion of fuel in the right wing tanks was likely caused by the improper setting of the fuel selector valves and the crossfeed valve during the flight.
- The pilot demonstrated insufficient knowledge regarding the operation of the aircraft's radio equipment and fuel system controls.