On December 27, 1986, a Piper PA-12-150 (registration N78475) was involved in an aviation accident near Gilcrest, CO. Investigators recorded the probable cause as: The pilot's failure to maintain adequate clearance from power lines while flying at low altitude, which resulted in an in-flight collision and crash. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot conducting a low-level pass over a river struck power lines and crashed onto a sandbar, shortly after waving to friends below.
What happened
The pilot initiated a low-altitude pass at approximately 200 feet above ground level (AGL) and waved to two friends who were engaged in duck hunting nearby. He subsequently made a second pass at roughly 150 feet AGL before departing the area. Approximately ten minutes later, the aircraft returned to the vicinity, flying at tree-top level down the river. During this flight, the aircraft struck three of four power lines and crashed onto a sandbar in the middle of the river.
The investigation
The investigation focused on the sequence of events leading to the impact with the power lines. Examination of the site confirmed that the aircraft collided with three power lines while flying at a very low altitude down the river channel. The crash occurred on a sandbar in the middle of the river, consistent with the witness account of the final flight path.
Findings
The primary factor contributing to the accident was the pilot's decision to fly at extremely low altitudes over a populated area with overhead utility infrastructure. The impact with power lines resulted in the loss of control and subsequent crash. No injuries were reported among the friends on the ground, but the severity of the impact suggests significant damage to the aircraft. The pilot's actions during the low passes demonstrated a lack of situational awareness regarding the height of the power lines relative to the terrain.
Probable cause
The pilot's failure to maintain adequate clearance from power lines while flying at low altitude, which resulted in an in-flight collision and crash.