Approach and Clearances
On the day of the accident, the aircraft was arriving in instrument flight rules (IFR) conditions. The pilot was vectored for an instrument landing system (ILS) approach to runway 25. At approximately 0909 Pacific standard time, the pilot was cleared for the approach and instructed to maintain 3000 feet until intercepting the localizer. Shortly thereafter, the controller instructed the pilot to contact the tower.
Altitude Deviation
Around the time of the handoff, the controller observed that the aircraft's transponder reply indicated an altitude of about 1700 feet. This was approximately 1100 feet below the minimum altitude at that position. The controller immediately queried the pilot about his altitude but received no response.
Pilot's Account
According to the pilot, everything appeared normal until the aircraft collided with power lines and crashed. The pilot stated that he believed he had been cleared to 2000 feet, and after intercepting the localizer, he began to descend to the glide slope.
Investigation Findings
An investigation revealed that the aircraft collided with power lines at an elevation of about 1525 feet. The accident occurred near the outer marker, where the minimum altitude was 2409 feet. No preimpact system malfunction or failure was found.