XTREMEAIR GMBH XA42 — Union City, TN

What happened

After completing pattern work at a local airport, the private pilot and flight instructor returned to the departure airport to use its aerobatic “box” for aerobatic maneuvers training. The co-owners of the airplane were sitting on the airport ramp watching the accident airplane and one of the co-owners reported seeing the airplane conducting an “avalanche” maneuver. This maneuver comprises a loop with a snap roll performed at the top of the loop. He reported that the airplane entered the maneuver about 1,200 ft above ground level (agl) and reached the top of the loop around 2,000 ft agl. However, he described that, rather than completing a 360° snap roll at the top of the loop, the airplane’s roll continued through 540° and was upright when it should have finished the roll inverted and continued through the remainder of the loop.

By this time, the airplane had slowed considerably, the engine was at full power, and the gyroscopic effect of the propeller pulled the nose down, and the airplane entered a spin. Once in the spin, the airplane descended to the ground, where it sustained substantial damage to the fuselage, empennage, and both wings.

Recovered flight data showed that, just before entering the last maneuver, the airplane’s GPS altitude was recorded as at least 1,135 ft. The last recorded GPS altitude was 1,693 ft, the derived groundspeed was 49 kts, and the engine parameters were consistent with similar previous aerobatic flights. The data were consistent with witness reports of the airplane entering a stall/spin.

Postaccident examination of the airplane and engine found no mechanical malfunctions or failures that would have precluded normal operation.

An editorial "what led to it / how to avoid it" analysis for this accident is generated separately and will appear here.