Incident Overview
An aircraft on an instrument approach to an airport was first identified on radar approximately 18 miles north of the field. Air traffic control provided radar vectors for a right downwind and base leg to runway 36R. While established on a downwind heading of 150°, the pilot was instructed to turn to a heading of 270° and asked if the airport was in sight. The pilot replied, '...we got it.' However, radar data indicated the aircraft continued its turn beyond the assigned heading, passing through 270° and reaching approximately 350°.
Sequence of Events
After traveling about half a mile on the 350° heading, the aircraft turned left to a heading of 250° and began descending. The turn continued until the aircraft was aligned on a southwest heading, roughly following a city street that passes south of the airport on a course of 250°. The altitude decreased at a consistent rate until reaching 900 feet, at which point radar contact was lost. The elevation at the approach end of runway 36R is 724 feet.
Wreckage and Lighting Conditions
The wreckage distribution was located along a heading of 245°. A flight inspection conducted at night under visual flight rules (VFR) determined that the edge lights of runway 36R were not visible beyond 30° of the runway centerline.
Pilot Activities
The pilot had awakened at 0730 on the day of the accident, November 14.
Probable Cause
The official probable cause was determined to be: reason for occurrence undetermined.