N396BKBordelon Bruce KITFOX IV · 2003

The pilot was flying his experimental airplane, practicing touch-and-go landings on his 1,400 foot long private grass airstrip. The weather was clear. During his third touch-and-go, he determined that he was going to land too long so he made a go-around. As he added power for the go-around, he started to feel vibrations and thought that he had a propeller malfunction. The vibrations continued regardless of power setting, so he shut the engine down and intentionally stalled the airplane about 10 feet above the ground to avoid rolling over when the airplane settled to the ground. The airplane came to rest in a corn field. The pilot saw that a fire had started in the engine compartment after ground impact, so he quickly exited the airplane. A post-crash fire then completely consumed the airplane. Examination of the airplane after the accident did not show any evidence of preimpact mechanical malfunction or abnormalities, although the fire damage was too extensive to specifically determine the reason for presumed propeller malfunction. After the examination, the pilot maintained that he was certain that there was a problem with the propeller and that it was the cause of the accident.

The accident occurred during the first flight since the experimental amateur-built airplane had been repaired from a previous accident. The pilot stated that after departure he performed two landings without incident. On the third landing attempt, the in-flight electrically adjustable propeller went into a low/flat pitch while the airplane was on an extended final approach. The pilot stated that the airplane lost forward thrust as result of the flat propeller blade pitch and that he landed short of the turf runway. The airplane subsequently nosed-over and came to rest inverted. The fuselage and empennage were substantially damaged. The pilot reported that there were no preimpact mechanical malfunctions or failures that would have precluded normal operation of the airplane. He stated that the flat propeller pitch may have been inadvertently set during flight when he mistakenly depressed the propeller pitch selector instead of the intended push-to-talk button. Both buttons were collocated on the control stick.

The pilot performed several maneuvers in the local area during a "phase 1" flight test. The pilot returned to the departure airport where he completed two normal landings on runway 04 (2,340 feet by 200 feet, grass) and was to perform a third landing. The pilot stated that during the third landing flare, the airplane sink rate was "too fast" and the nose wheel contacted the runway. The airplane then nosed over. The airplane was configured with full flaps. Damage to the airplane included a buckled fuselage and vertical stabilizer. The pilot was uninjured. The pilot stated that engine power should have been applied to control the sink rate. Examination of the accident site revealed a ground scar in a field about 130 feet from the runway threshold or about 30 feet from the runway edge. The ground scar was consistent with the airplane's initial touchdown point. The pilot said that he would usually use an aim point that was about 100 feet past three yellow cones that delineated each side of the threshold.