Airplane Factory (Pty) Ltd The SLING N511NG accident near Daggett, California

Probable cause

The pilots’ failure to maintain clearance from terrain while operating in dark night, visual meteorological conditions. Contributing to the accident was the pilots’ failure to enable the aural terrain warning system.

NTSB analysis

The sport pilot and flight instructor were approaching the destination airport at the conclusion of a night cross-country flight in the light sport airplane. The sport pilot stated that, about 10 miles southwest of the airport, they could clearly see the airport lights and began a visual descent from 5,500 ft mean sea level. During the descent, the airplane collided with terrain about 5 miles from the airport and came to a stop. The sport pilot egressed and called for emergency services.

Postaccident examination of the airframe and engine revealed no mechanical anomalies that would have precluded normal operation. Visual meteorological conditions were present in the area with visibility of 10 miles. Astronomical information showed that moonset had occurred about 3.5 hours before the accident. The accident occurred in a very sparsely populated area of high desert, with no ground lighting. The terrain and dark night conditions would have prevented both pilots from maintaining a visual reference to the terrain.

Examination of the airplane's Electronic Flight Information System (EFIS) revealed that the aural terrain warning function was not enabled, though the system still depicted a moving map display with terrain information. If the aural terrain warning function had been enabled, the pilots would have been alerted, and action could have been taken in sufficient time to maintain terrain clearance.

Text from the NTSB. Open the NTSB docket for WPR14LA177 for the full record.