Cessna 182S N23750 accident near Napa, California

Probable cause

The instrument-rated pilot’s loss of situational awareness and failure to follow the prescribed instrument departure clearance/procedure, which resulted in an in-flight collision with the terrain.

NTSB analysis

The instrument rated pilot was planning a cross-country flight from his home airport in low fog conditions. The pilot received an instrument flight rules (IFR) clearance about 15 minutes prior to departure from runway 18R. Witnesses reported observing the airplane pass directly over their work site at a very low altitude about 1 mile south of the airport. Recorded radar data disclosed that the airplane was airborne for about 1.5 minutes. Following departure, the airplane made a left bank while gradually increasing its altitude to 1,000 feet mean sea level (msl) to an easterly heading. The last two returns show an altitude of 900 feet msl and a slight change of direction back toward the south. The last radar return was located about 0.5 miles north of the accident site. The departure clearance dictated that the pilot was to continue straight on the runway heading of 180 degrees until intercepting a VOR radial about 6 miles from the airport. Thereafter, he was to make a left turn to join the radial and follow it to the first intersection on the departure route (about 10.25 miles south of the airport). The accident occurred during the hours of darkness with a full moon about 12.9 degrees above the horizon. A routine aviation weather report (METAR) disclosed that during the time of the accident there was an overcast cloud layer at 600 feet agl and 10 miles visibility. The pilot received an Instrument Competency Check several days prior to the accident and reportedly frequently flew with sole reference to the instruments. Ground scar analysis, impact signatures, and wreckage fragmentation patterns disclosed that the airplane impacted terrain in a near level attitude, with high forward velocity. There was no evidence of a pre-mishap mechanical malfunction or failure observed during the examination of the engine or airframe.

Text from the NTSB. Open the NTSB docket for WPR09FA385 for the full record.