Cessna 172 N7870U accident near Brookings, Oregon

Probable cause

The pilot's spatial disorientation and loss of situational awareness during the departure turn in dark night conditions, which resulted in an in-flight collision with water.

NTSB analysis

The non-instrument-rated pilot departed for the third leg of a cross-country flight in the airplane during dark (moonless) night conditions. The departure path was toward the ocean and over an area with few ground-based light sources to provide visual cues. A witness heard an airplane flying nearby and assumed that it was taking off from the airport. As the airplane continued, he heard a reduction in engine power, like a pilot throttling back while landing. According to the witness, the engine did not sputter. Review of the recorded radar data showed that the airplane turned left shortly after takeoff and climbed to about 700 ft above ground level as it passed near the witness's location. The airplane did not arrive at its destination, and a search was initiated. The wreckage of the airplane was found in ocean waters about 2 miles west of the departure airport. Although visual meteorological conditions prevailed, no natural horizon and few external visual references were available during the departure. This required the pilot to monitor the flight instruments to maintain awareness of the airplane's attitude and altitude. Given the lack of external visual cues and the the pilot's lack of recent night flight experience and his lack of an instrument rating, it is likely that the pilot became spatially disorientated during the departing left turn.

The main wreckage was not recovered. Therefore, it could not be determined whether any preimpact mechanical malfunctions or anomalies were present.

Text from the NTSB. Open the NTSB docket for WPR16LA138 for the full record.