Low-Altitude Maneuvering · NTSB WPR11FA390

PIPER PA-18-150 — Forsyth, MT

2 fatal High-time pilotLow altitude
DateAugust 18, 2011
LocationForsyth, MT
AircraftPIPER PA-18-150
Purpose of flightAerial Observation
ConditionsDay · Visual Meteorological Cond
Phase / occurrenceManeuvering Collision with terr/obj (non-CFIT)
Pilot age39
Pilot total time3,000 hrs · High time
Time in type500 hrs
Fatalities2

Probable cause

The pilot’s failure to maintain adequate airspeed while maneuvering, which resulted in a stall/mush, loss of control, and impact with terrain.

NTSB findings

  • Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Airspeed-Not attained/maintained - C
  • Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Angle of attack-Not attained/maintained - C
  • Personnel issues-Task performance-Use of equip/info-Aircraft control-Pilot - C
  • Environmental issues-Physical environment-Terrain-(general)-Not specified

What happened

The operator reported that the pilot and passenger were going to survey a prairie dog town and take pictures. Hunters in the accident area observed the airplane fly overhead and descend below mountainous terrain while in a turn. The airplane crashed in an open field. The airplane damage and the ground scars at the accident site were consistent with the airplane being in a stalled condition at the time of the accident. The pilot likely failed to maintain adequate airspeed as he was increasing the bank angle to maintain visual reference to the ground, which resulted in a stall/mush, loss of control, and collision with terrain. A postaccident examination of the airframe and engine revealed no evidence of a mechanical failure or malfunction 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.

View the official NTSB docket →