What happened
On April 10, 2008, at approximately 17:00 UTC, a Fuji FA-200-180 was performing aerobatic maneuvers near Breitenau, Lower Austria. The pilot had departed from Wr. Neustadt Ost (LOAN) airfield with a passenger. After completing a left and right roll, the aircraft was climbing through approximately 4,200 ft when the engine experienced a sudden loss of power.
Despite the pilot's attempts to restore engine performance, the power loss persisted. The pilot initially attempted to reach a nearby level field for an emergency landing, but determined the field was unreachable. Consequently, the pilot prepared for a forced landing within a wooded area. During the descent, the aircraft struck several trees at a minimum speed of approximately 50 knots, uprooting one tree and ultimately crashing to the ground. The impact involved a vertical force of approximately 7G. Both the pilot and the passenger sustained minor injuries, and the aircraft was destroyed.
The investigation
An investigation by the SUB established that the aircraft's weight and center of gravity were within permissible limits and that the pilot possessed the necessary licenses and sufficient experience for the flight. Weather conditions were favorable for VFR flight and did not contribute to the accident.
While initial on-site examinations of the engine and aircraft showed no immediate defects, subsequent testing of the engine on a test bench revealed starting difficulties, RPM fluctuations, and poor throttle response. Detailed inspection of the fuel injection system uncovered significant amounts of lubricant in both the internal and external components.
Findings
- The primary cause of the accident was the aircraft's collision with ground obstacles (trees).
- A contributing factor was the loss of engine power during flight.
- The loss of power was caused by the fuel injection system's inability to deliver an adequate, combustible mixture to the engine.
- This failure resulted from the use of an unknown lubricant on the manual mixture control shaft. A chemical reaction between this lubricant and the AVGAS 100LL fuel caused the lubricant to migrate, clogging various bores and passages within the fuel injection system.