Cessna 172S N15963 accident near Incline Village, Nevada

Probable cause

The pilot's decision to initiate a flight for which he was neither approved nor qualified and his failure to maintain terrain clearance during the flight. Contributing to the accident were the dark night, the mountainous terrain, and the pilot's medical condition.

NTSB analysis

The student pilot initiated a 160-nautical-mile night cross-country flight without approval from his flight instructor for the intended purpose of gambling at a casino. Radar data and wreckage distribution were consistent with the airplane making a gradual controlled descent from cruise flight and impacting mountainous terrain on a direct course toward the intended destination. No preimpact anomalies were noted during examination of the airframe and engine. The pilot's total flight time was approximately 97 hours, of which 19 hours were solo. His total night flight time was 1.8 hours dual instruction, which took place during a single flight on the night before the accident. He had made solo cross-country flights to airports less than 50 nautical miles from his home airport, but had not yet received training in cross-country flight planning. Toxicological testing revealed that the pilot, a physician diagnosed with substance dependence, had been using cocaine and taking two prescription medications (lamotrigine and quetiapine) often used in the treatment of bipolar disorder, as well as a prescription antidepressant (fluoxetine), though the levels detected indicated he had not used cocaine within 24 hours of the accident and had likely recently discontinued use of the medications. Additionally, the testing detected buprenorphine, a prescription narcotic medication, at a level consistent with the chronic use of the medication for treating opioid dependence. The pilot had been treated on multiple occasions for substance dependence and abuse. The relatively recent use of a stimulant (cocaine), recent discontinuation of prescription medications, gambling, and the apparent intent to fly cross-country at night while a student pilot without approval from his instructor all are actions consistent with the pilot being in a manic episode of bipolar disorder at the time of the accident. It is also possible that he was experiencing some cognitive impairment as a result of his use of buprenorphine for the treatment of substance dependence.

Text from the NTSB. Open the NTSB docket for LAX08FA261 for the full record.