Rans S7 — Kingsland, TX

What happened

The pilot and passenger had recently completed maintenance work on the engine to address engine sputtering that occurred during steep climbs. A witness who was familiar with the troubleshooting stated that, on the day of the accident, the pilot's plan was to complete steep climbs to determine why the engine sputtered during that maneuver. The wind was from the south at 15 knots and gusting to 25 knots; the airplane departed to the south into the wind. The witness reported observing what he considered a "normal" takeoff, followed by a steep 15 to 20 second climb. At the top of the climb, the nose and left wing suddenly dropped, and the airplane entered a left-turning spiral, completing 3 to 4 slow rotations before impacting the ground. The witness stated that the engine sounded normal the whole time and he did not notice anything wrong.

The airplane impacted the ground in a nose- and left-wing-low attitude and came to rest upright. A postimpact fire consumed a majority of the airplane. A postaccident examination of the airplane did not reveal any anomalies that would have precluded normal operation; however, the examination was limited due to the extent of the fire damage.

The accident circumstances are consistent with pilot executing a steep climb to troubleshoot an engine issue. During the steep climb in gusting wind conditions, the airplane's critical angle of attack was exceeded which resulted in an aerodynamic stall, and spin into terrain.

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