Accident Sequence
The aircraft was on an IFR flight plan and was being vectored for an ILS runway 7 approach. After being cleared for the approach, the pilot was instructed to intercept the localizer from the south side. The last assigned altitude was 2000 feet MSL. Radar data indicated that the aircraft continued across the localizer toward rising terrain. Air traffic controllers issued instructions for the pilot to turn back to the localizer, but the pilot did not follow those instructions. Controllers then issued urgent instructions to turn and climb. According to controllers, the pilot calmly acknowledged their transmissions but continued toward rising terrain. Radar contact was lost, but the airplane eventually turned south. However, it struck avocado trees on the west side of sloping terrain at an elevation of about 440 feet MSL while in a steep bank.
Mechanical and Pilot Background
No preimpact mechanical anomaly was found that would have resulted in the accident. The pilot's former wife recalled instances when he had mis-set the autopilot OBS. On those occasions, he similarly deviated from the localizer at intercept and resisted her suggestion to take over manually and fly the approach, persisting in trying to make the autopilot fly the approach. A flight instructor who administered a biennial flight review one month earlier found the pilot's instrument flight skills weak and refused to certify his instrument competency.
Toxicology
Toxicology tests of tissue from the pilot indicated the presence of a narcotic pain reliever and its metabolite. Tests of kidney tissue showed 0.337 mcg/ml Propoxyphene and 2.7 mcg/ml Norpropoxyphene; tests of muscle tissue showed 0.385 mcg/ml Propoxyphene and 1.9 mcg/ml Norpropoxyphene.