Incident
Aircraft was cleared for a localizer approach to runway 11. Approximately three minutes later, the second-in-command reported that they were not receiving the localizer and requested confirmation of course alignment. The LAX ARTCC R-15 controller observed the aircraft was right of course and below the required altitude. The aircraft's Mode C transponder indicated an altitude of 1,400 feet, and the controller advised the crew to maintain at least 2,300 feet until past the final approach fix. The crew responded that they were in visual meteorological conditions. Radar service was terminated and a frequency change to tower was approved. Shortly thereafter, the aircraft struck a eucalyptus tree at about 90 feet above ground level, approximately 2.05 miles from the approach end of the runway and about 195 feet right of the localizer course. The elevation of the crash site was 101 feet; the minimum descent altitude for the approach was 640 feet. No preimpact part failure or malfunction was found. All four occupants were killed.
Weather Conditions
The weather at 0645 Pacific Daylight Time was reported as: indefinite ceiling, 100 feet obscured, visibility 1/8 mile in fog, wind from 220° at 4 knots.
Probable Cause
The official probable cause was the pilot's improper IFR (instrument) procedure and his failure to maintain the minimum descent altitude for the approach. Adverse weather was a related factor.