Cessna 172G N5800R accident near Hartington, Nebraska

Probable cause

The pilot’s decision to use an excessive, unapproved flap setting for takeoff, which significantly increased the induced drag and resulted in an aerodynamic stall when the airplane flew out of ground effect.

NTSB analysis

The private pilot reported that he departed from a private grass airstrip with the airplane's flaps set to 30 degrees. He then climbed the airplane to about 20 ft above ground level (agl) and continued to the southwest. About 50 ft agl, as the pilot reached over to raise the flaps 10 degrees, the engine lost partial power. The yoke abruptly came back toward him, the airplane's nose pitched up, and the stall warning horn sounded. He pushed the yoke forward as hard as he could with both hands and trimmed the nosewheel down, but the trimwheel was hard to turn, almost requiring two hands to move it. He reached over to the flap handle and "bumped" it to 10 degrees. The airplane then aerodynamically stalled, and it impacted the ground in a steep nose-down attitude.

Postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. The damage to the propeller indicated that the engine was developing power at the time of ground impact. The airplane owner's manual stated that "Flap settings of 30- to 40-degrees are not recommended at any time for take-off." Although the pilot reported a partial loss of engine power, it is likely that flying the airplane out of ground effect with the flap setting of 30 degrees significantly increased the induced drag, which created the effect of not having sufficient engine power to overcome the drag and prevent an aerodynamic stall.

Text from the NTSB. Open the NTSB docket for CEN15LA343 for the full record.