Accident Sequence
The pilot was cleared by air traffic control (ATC) for an instrument landing system (ILS) approach in instrument flight conditions. During the approach, ATC observed on radar that the airplane had descended below the minimum altitude for that segment of the approach and was executing S-turns through the final approach course. In response, ATC terminated the ILS approach and vectored the pilot for an airport surveillance radar (ASR) approach.
While on the ASR approach, the airplane was again observed on radar turning through the final approach course. ATC provided heading corrections to the pilot, but these corrections were not acknowledged. The airplane continued turning through the approach course, after which radar contact was lost.
Pilot History
The pilot's last recorded instrument flight was on September 15, 1989. The last recorded night flight was on February 18, 1989.