John Wayne Apt/Orange Co. Airport
Aircraft Accident/Incident Report

Santa Ana, California 92707
Tuesady, June 23, 1998 17:07 PDT

While the solo student pilot of the Cessna 152 was on downwind leg for landing, the air traffic controller directed the student's attention to a Boeing 757 aircraft that was preceding the student's aircraft for landing on the parallel runway. The threshold of the parallel runway is abeam and 500 feet to the right of the runway the student was to land on. The controller then advised of a 10-knot quartering headwind from the right, issued a wake turbulence precaution, and cleared the student pilot for the landing option. Witnesses reported that as the student pilot was on final approach, descending through approximately 100-foot altitude (agl), the aircraft abruptly rolled inverted and crashed short of the runway threshold. The Safety Board prepared a Study of Wake Turbulence Encounter using data from the Boeing 757's flight data recorder, tower communication tapes, and tower reported surface winds. The report concluded that the Cessna 152 descended into the Boeing 757's wake when the wake was 37 to 41 seconds old. The student's flight instructor told the Safety Board that the student, who had 136 hours of dual instruction and 20 hours of solo flight time, had received instruction in wake turbulence avoidance at three points in ground instruction. Furthermore, the instructor said that training as they had at the air carrier airport, most flights involved wake turbulence avoidance.

The failure of the pilot-in-command to identify a proper touchdown point on the runway and maintain an appropriate glidepath so as to remain clear of vortex turbulence from the preceding large aircraft. A factor in the accident was the pilot's failure to initiate a go-around in the known presence of vortex turbulence.