Piper PA-18 N7276D accident near Sleetmute, Alaska

Probable cause

Operation of the airplane by a non-certificated pilot and his failure to maintain adequate airspeed and airplane control, which resulted in an aerodynamic stall.

NTSB analysis

About 30 minutes after the uncertificated pilot and a passenger departed for a reconnaissance flight, a witness saw the airplane flying "low and slow" over the treetops toward the intended landing site. As the airplane flew toward the landing site threshold, it began a slight right turn, then it nosed down abruptly, and the engine speed increased to a very high rpm setting. The airplane continued the near-vertical, steep descent, and it began a 3/4 spiral turn downward, indicative of an aerodynamic stall, before descending from view into the trees at the approach end of the site. An NTSB on scene wreckage examination of the airplane did not disclose any preimpact mechanical malfunctions. It is likely that the pilot failed to maintain adequate airspeed during the low-altitude approach, which resulted in an aerodynamic stall from which he could not recover even with the addition of engine power.

Text from the NTSB. Open the NTSB docket for ANC12FA028 for the full record.