What happened
On 3 April 2004, an Andreasson BAIT aircraft, registration G-JEDS, was taxiing on the grass surface at White Waltham Airfield, Berkshire. The pilot was maneuvering the aircraft toward the hangar or fuel pump area following a landing. Due to an 18 kt tailwind, the pilot was holding the control stick forward to prevent the tail from lifting.
While navigating through thicker grass, the aircraft began to lose speed. In an attempt to maintain momentum, the pilot briefly increased the throttle while simultaneously using differential braking to execute a zig-zag taxi pattern for better visibility. During this maneuver, the aircraft suddenly pitched forward onto its nose, causing the propeller to strike the ground. The pilot immediately shut down the engine, fuel, and electrics, and exited the aircraft via the canopy while awaiting rescue services.
The investigation
Investigators examined the sequence of events and the pilot's actions during the taxi. The investigation established that the aircraft's propeller was damaged and the engine sustained a shock load. The pilot's assessment indicated that the sudden increase in power caused the propeller wash to create enough airflow over the tail to overcome the force of the tailwind. This resulted in the tail lifting rapidly, leading to the nose-over.
Findings
- The primary cause of the accident was that the increase in throttle power created enough airflow over the tail to overcome the tailwind, causing the tail to lift and the aircraft to pitch forward.
- The pilot was holding the stick forward to counter the tailwind, whereas holding the stick aft would have been more appropriate once the tail began to lift.
- The pilot's attention was divided between deciding on a parking location and the physical task of taxiing, which contributed to the error.