On April 22, 1984, a Piper PA-25-235D (registration N9866P) was involved in an aviation accident near Heppner, OR. Investigators recorded the probable cause as: The pilot's encounter with a downdraft while maneuvering at low altitude below a ridge line, which led to the aircraft settling into the ground and subsequent collapse of the landing gear. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot executing a low-level turn below a ridge encountered a downdraft, causing the aircraft to settle into the ground. The landing gear collapsed, and the aircraft was destroyed by fire.
What happened
The pilot reported that he was conducting a maneuver below the lee side of a ridge line at an altitude of approximately 30 feet above ground level (AGL). During this phase of flight, the aircraft reportedly encountered a downdraft which caused it to settle into the terrain. As the aircraft impacted the ground, the landing gear collapsed. There was no other major structural damage reported from the initial impact.
Shortly after the aircraft came to rest, it began to burn. The fire resulted in the total destruction of the aircraft.
Probable cause
The pilot's encounter with a downdraft while maneuvering at low altitude below a ridge line, which led to the aircraft settling into the ground and subsequent collapse of the landing gear.