What happened
On August 30, 2008, an ultralight aircraft, a Rans S-12 Airaile, departed from the Torgau-Beilrode landing field for a circuit flight. After a takeoff roll of approximately 200 meters on the grass runway, the aircraft entered a steep initial climb. Within 10 to 15 seconds of flight, the engine failed while the aircraft was at an altitude of only 30 to 40 meters. Following the loss of power, the aircraft rolled over the right wing and struck an adjacent field. The pilot sustained fatal injuries.
The investigation
The BFU investigation focused on the mechanical state of the aircraft and the operational procedures. Investigators found that the engine and propeller had no external damage, and the crankshaft remained rotatable. While the fuel system showed evidence of leakage, no fuel was found within the carburetor. Crucially, the investigation established that the fuel shut-off valve was found in the closed position.
Furthermore, the investigation examined the aircraft's documentation. The flight and operating manual lacked specific instructions regarding emergency procedures or instructions for the use of the rescue system. Additionally, the checklists used for operating the aircraft did not include a requirement to verify the position of the fuel shut-off valve prior to flight.
Findings
- The primary cause of the engine failure was the closed fuel shut-off valve, which resulted in a lack of fuel during the initial climb.
- The aircraft's altitude was insufficient to establish a controlled flight attitude following the power loss.
- The pilot was not sufficiently familiar with the specific handling characteristics of the Rans S-12, particularly the pitch tendencies associated with its pusher configuration.
- The aircraft's manual and checklists were deficient, as they failed to mandate a check of the fuel shut-off valve and lacked guidance on engine-out emergency procedures.