SEA04LA014

On October 19, 2003, approximately 1030 Pacific daylight time, an unregistered Tracy Kolb Mark III impacted the runway just after liftoff from Prineville Airport, Prineville, Oregon. The private pilot, who was the sole occupant, received serious injuries, and the aircraft, which was owned and operated by a friend of the pilot, sustained substantial damage. No flight plan had been filed for the 14 CFR Part 91 local aircraft evaluation flight, and visual meteorological conditions were reported to have existed at the time of the accident.

According to the pilot, who was conducting a series of evaluation flights on a recently built unregistered aircraft, this was only the second time he had flown a pusher-type aircraft. In both cases those flights had been made in this specific aircraft, and together totaled two-tenth of an hour. During the first flight, which occurred about a month before the second, and lasted only long enough for the aircraft to be flown around the pattern for landing, the pilot was unable to keep the aircraft from porpoising during most of the time it was airborne. After he turned final for landing, the aircraft continued to porpoise, and he had a "...hard time getting a throttle setting that would allow a smooth descent." Because the aircraft was still porpoising as he attempted to flare for touchdown, he made "...an exceedingly hard landing."

After that flight, the pilot told the owner that he thought the throttle was too sensitive, and that its location should be changed. Prior to the second flight, the owner moved the throttle to the left side of the cockpit, changed its linkage to make it less sensitive, and moved the horizontal stabilizer from the designed position, inline with the fuselage tube, to a location higher up on the vertical stabilizer.

During the flight that ultimately led to the accident, the pilot pulled onto runway 28, applied power, and lifted off to a height of about five feet. He then immediately cut the power and landed straight ahead in what he described as a "fairly smooth landing." Then, because he still had a lot of runway left, he attempted another liftoff. This time the aircraft's nose pitched up significantly steeper than he thought it would, and the aircraft quickly climbed to a height of 10 to 20 feet above the runway. The pilot therefore "immediately cut the power" and the aircraft pitched to a steep nose down attitude, and made a "very hard landing." As the aircraft impacted the runway surface, the pilot accidentally "hit the throttle" and the aircraft lifted off a second time. The pilot therefore "...chopped the throttle," resulting in the aircraft hitting "fairly hard" a second time. At that point, because he had been severely injured by the two impacts, the pilot was no longer able to make control inputs, so he "...let the aircraft run off the runway and stop on its own."

During a post-accident inspection of the aircraft by an FAA Airworthiness inspector, it was confirmed that the aircraft's horizontal stabilizer attach point had been modified from the standard Kolb configuration, and it was also determined that after the accident the left wing spar attach fitting pin was no longer in its fitting. The pin was later located at a point near the first hard impact, and it was noted by both the pilot and witnesses that during all three liftoffs, the aircraft did not roll to the right or the left, but instead climbed and descended straight ahead. According to the FAA Inspector, there was no evidence of any problems with the flight controls, and there was no indication that there had been any other aircraft anomalies that would have contributed to the accident sequence.

During a telephone conversation with the Investigator-In-Charge, the pilot stated that during takeoffs in aircraft that he does not have much experience in, he likes to make a "quick transition" from the runway surface to flight, so that he does not have to spend much time in the "transition area" where the actions of the aircraft are less predictable.