N10637

On September 23, 1995, at 0717 hours Hawaiian standard time, a Cessna 150L, N10637, was substantially damaged when the pilot lost control of the aircraft during a landing approach and impacted on runway 17 at the Keahole Airport, Kona, Hawaii. The instructional flight was conducted in visual meteorological conditions and the solo student pilot sustained minor injuries. The local area flight originated at the Keahole airport about 0615.

The flight was the student's second unsupervised solo flight and she was to remain in the airport traffic pattern to practice a series of soft-field takeoffs and landings. The pilot reported that on her eighth landing she was cleared by the Keahole Tower for a stop-and-go landing behind a military C-130 transport aircraft and to extend her downwind leg to follow that aircraft. The pilot told investigators that she was aware of the wake turbulence hazard and that she intended to fly her approach above the glidepath of the C-130. She reported that the approach was normal until approximately 10 feet above the runway when the "aircraft veered swiftly to [the] right dipping down and nosing over to collide with [the] runway".

Runway 17 at the Keahole Airport is 11,000 feet long and 150 feet wide. Inspectors from the FAA's Honolulu Flight Standards District Office (FSDO) reported that initial impact marks were found on the runway, slightly right (west) of centerline and 362 feet beyond the runway threshold. The marks were made by the nose landing gear, propeller, and right main landing gear. The aircraft then flew about 65 feet before again contacting the runway and sliding on its nose approximately 270 feet along a curving path to the right. It came to rest on the right (west) edge of the runway, 700 feet beyond the threshold, heading approximately 200 degrees. The FSDO inspectors also listened to tape recordings of communications at Keahole Air Traffic Control Tower. The time from when they were first able to determine that the C-130 aircraft was on the ground until the ELT operated on the accident aircraft was 2 minutes and 18 seconds. Surface winds were 4 knots or less at the time of the accident.

The student pilot reported a total flying time of 30 hours, of which 14.6 hours were with the current flight instructor. The instructor told investigators that she had completed 11 lessons with the student and that procedures for avoiding wake turbulence were included in the lesson 3 syllabus. In addition, wake turbulence procedures had been demonstrated on at least six occasions while the student was landing behind large aircraft during dual instructional flights.