Casualties unknown

Modified Piper PA-22 crashes shortly after takeoff during dusk operations (N9978D)

Leavenworth, WA, US

On July 30, 1990, a Piper PA-22-150 (registration N9978D) was involved in an aviation accident near Leavenworth, WA. Investigators recorded the probable cause as: The pilot's decision to take off under high-density altitude conditions and the use of full flaps for climbout, which resulted in inadequate performance and control of the aircraft. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-06-10Data APIEditorial standards

A modified Piper PA-22 crashed approximately half a mile from the departure end of an airstrip shortly after takeoff at dusk. The pilot had waited for temperatures to cool before attempting the flight.

What happened

The pilot of a modified Piper PA-22 operated at an airstrip where conditions required careful timing due to rising temperatures. Anticipating performance limitations associated with high ambient heat, the pilot delayed departure until the temperature had dropped as much as possible before dusk.

Upon commencing the flight, the pilot elected to use full flaps for the climbout phase. This technique was selected based on the pilot's understanding that it was recommended by the aircraft owner's handbook. Despite these precautions, the aircraft failed to maintain adequate performance during the initial ascent. The accident occurred approximately one-half mile from the departure end of the airstrip.

The investigation

The investigation focused on the operational decisions made prior to and during the takeoff roll. Key factors examined included the ambient temperature at the time of departure and the specific configuration used for climbout. The pilot's reliance on full flaps for climb was analyzed against standard performance data for the modified aircraft.

Findings

The primary contributing factor was the aircraft's inability to sustain flight after takeoff under high-density altitude conditions. The use of full flaps during climbout, while believed by the pilot to be a recommended technique, did not provide sufficient lift or climb gradient to clear obstacles or maintain safe flight in the thin air. The proximity of the crash site to the runway end indicates a failure to gain altitude effectively immediately after leaving the ground.

Probable cause

The pilot's decision to take off under high-density altitude conditions and the use of full flaps for climbout, which resulted in inadequate performance and control of the aircraft.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X23820. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.