Introduction
ATI Flight 805 departed from Seattle at 23:20, bound for Toledo. The first officer was flying the instrument landing system (ILS) approach to runway 07. For reasons that were not determined, the first officer failed to properly capture the ILS localizer and/or glide slope during the approach.
Approach and Go-Around
At 03:13, the captain decided to initiate a go-around. The aircraft was subsequently vectored onto a base leg and given a heading of 100° to intercept the final approach course again. A crosswind of 35 knots from 180° affected the approach, and the first officer had difficulty capturing the localizer and glide slope.
Final Approach and Warnings
At 03:24, as the first officer attempted to stabilize the approach, three ground proximity warning system (GPWS) glideslope warnings and sink rate warnings sounded. The captain took over control of the aircraft at 03:24:17 and performed another missed approach maneuver.
Unusual Attitude and Crash
During this maneuver, the captain became spatially disoriented and inadvertently allowed an unusual attitude to develop, with bank angles reaching up to 80° and pitch angles up to 25°. While the aircraft was in a nose-low and left bank attitude, control was transferred back to the first officer, who began leveling the wings and raising the nose. However, impact with the ground occurred before the unusual attitude recovery was completed. All four occupants were killed.
Probable Cause
The probable cause of the accident, as determined by the investigation, was the failure of the flight crew to properly recognize or recover in a timely manner from the unusual aircraft attitude that resulted from the captain's apparent spatial disorientation, which itself resulted from physiological factors and/or a failed attitude director.