Cessna A185F N4585F accident near Coeur D'Alene, Idaho

Probable cause

The pilot's failure to maintain clearance from trees while maneuvering at low altitude in mountainous terrain.

NTSB analysis

The private pilot was on a local personal flight in the airplane. According to witnesses, the pilot appeared to fly a series of practice approaches at a remote private airstrip and then flew northeast up a nearby canyon towards rising mountainous terrain. The airplane impacted trees on the canyon hillside about 1 mile from the airstrip on a southwest heading, indicating that the pilot had reversed course. It is likely that the pilot realized that the canyon narrowed ahead and that he was surrounded by rising terrain. He likely attempted to turn the airplane around, and while maneuvering in the turn, he was unable to maintain clearance with the trees on the canyon hillside.

No significant weather or turbulence was reported or forecast in the area, however wind at the time of the accident may have created some light turbulence, though it is unlikely to have affected the flight.

Postaccident examination of the airframe and engine revealed no evidence of pre-impact mechanical malfunctions or failures that would have precluded normal operation. The engine was subsequently test run in a test cell at various power settings with no anomalies noted.

It is unlikely that the pilot's elevated blood pressure, insomnia, or medications used to treat these conditions impaired him or contributed to the accident. Additionally, it is unlikely that the pilot's antidepressant medications contributed to the accident. The pilot had used the potentially-impairing medication tramadol before the accident. However, because of variations in patient tolerance to opioid medications and possible postmortem changes in drug concentrations, the investigation was unable to determine if the pilot was impaired by tramadol at the time of the crash.

Text from the NTSB. Open the NTSB docket for WPR16FA131 for the full record.