Piper PA28 N317LB accident near Harlowton, Montana

Probable cause

The pilot’s failure to follow the appropriate takeoff procedures, which resulted in a collision with terrain.

NTSB analysis

The pilot conducted a short-field takeoff in high density altitude conditions, with the airplane close to, or slightly above its maximum gross weight. During the initial climb, the airplane accelerated to best rate-of-climb speed, but it descended back to the ground, collided with a fence, and nosed over.

In the days leading up to the flight, the pilot had expressed concern that the engine was not producing maximum power, so he had it examined by an airframe and powerplant mechanic. The mechanic stated that both the engine and tachometer were operating appropriately.

The pilot told investigators that it was his habit to take his hand off the throttle during takeoffs and place both hands on the yoke. Postaccident examination revealed that the, throttle was found slightly aft of the full-forward position, the carburetor heat control was partially backed out, and the flaps were extended. It is likely the throttle backed out during takeoff and engine performance was further reduced by the carburetor heat control being partially backed out. Additionally, the airplane procedures for a short field-takeoff called for the slow retraction of the flaps after takeoff.

The circumstances of the accident are consistent with a loss of climb performance occurring after a heavyweight, high density altitude takeoff due the pilot’s failure to properly set and monitor the engine controls and retract the flaps as required.

Text from the NTSB. Open the NTSB docket for WPR20LA278 for the full record.