Boulder, CO, USA
N4JU
HAUSER U/HAUSER J KIT FOX CL
The pilot reported that when he was taking off on his first solo flight in the recently purchased airplane, the electrically operated propeller started to increase pitch. The pilot stated that he tried to decrease the pitch, but each time he released the control-stick-mounted propeller button, the propeller pitch would increase. After the prop went to a high pitch angle and the engine started to run "rough," the pilot elected to conduct a forced landing and turn back to the runway. A Certified Flight Instructor (CFI), who flew with the accident pilot on two previous flights, reported that the propeller controls for pitch are two buttons on the top end of the control stick (one to increase and the other to decrease pitch). He added that it was easy to inadvertently touch and to confuse which button increased and which button decreased propeller pitch. The CFI also noted that it was easy to confuse the propeller pitch buttons with similar elevator trim buttons located on the control stick. The CFI added that on several occasions he and the accident pilot mistakenly actuated the propeller control the wrong way. During the second flight with the accident pilot, the CFI said that they planned to practice takeoffs and landings. During the session, the CFI accidentally coarsened the prop pitch to its maximum setting; the power loss was "large", and the CFI closed the throttle and landed. Furthermore, the CFI reported that he had to intervene in "all, except one of the landings and most of the take-offs, performed by the accident pilot." The CFI reported that he told the accident pilot that he thought that he needed much more than two hours of dual instruction required by the insurance company.
On November 24, 2008, approximately 1245 Mountain Standard Time, a single-engine, Kit Fox airplane, N4JU, was substantially damaged during a forced landing following a reported loss of engine power, shortly after takeoff from the Boulder Municipal Airport (KBDU), Boulder, Colorado. The commercial rated pilot received minor injuries. The airplane was registered and operated by a private individual. Visual meteorological conditions prevailed and a flight plan was not filed for the 14 Code of Federal Regulations Part 91, cross-country flight. A Federal Aviation Administration (FAA) Inspector, who responded to the accident site, reported that the airplane was largely consumed by a post-crash fire. During the forced landing, the airplane hit a fence before coming to rest in an open field near airport property. The pilot reported to the FAA had he just purchased the airplane and was ferrying it back to his home when the accident flight occurred. In his written statement, the pilot reported that during the take-off, the airplane's electrically operated propeller started to increase propeller pitch. He tried to decrease the pitch, but each time he released the control stick mounted propeller button, the propeller pitch would increase. After the prop went to a high pitch angle and the engine started to run "rough", the pilot elected to conduct a forced landing and turned back to the runway. The pilot added, he managed to reduce the propeller pitch, but "a secondary failure of the propeller indicator [occurred], reading maximum pitch when in reality it was zero-degree's pitch." He was able to exit the airplane before the post-crash fire erupted. A witness reported that he saw the accident airplane depart the runway and that it "seemed to be having trouble producing power, [but it] continued taking-off. At approximately 100-feet it seemed to stop producing power altogether." The witness added he saw the smoke and flames and rushed to the scene; where the pilot appeared in "good shape" and was stating that, "the prop went into reverse." A Certified Flight Instructor (CFI), who flew with the accident pilot on two previous flights, reported that the airplane had excellent handling characteristics and that the propeller turned "anti-clockwise." The CFI added that the propeller controls for pitch are two buttons on the top end of the control stick (one to increase and the other to decrease pitch). He added that it was easy to inadvertently touch and to confuse which button increased and which button decreased propeller pitch. The CFI also noted that it was easy to confuse the propeller pitch buttons with similar elevator trim buttons located on the control stick. The CFI added that on several occasions he and the accident pilot mistakenly used the propeller control the wrong way. During the second flight with the accident pilot, the CFI said that they planned to practice takeoff and landings. During one of the takeoffs, the CFI accidentally coarsened the prop pitch to its maximum setting. The CFI reported that the power loss was "large", so he closed the throttle and landed. Furthermore, the CFI reported that he had to intervene in, "all, except one of the landings, and most of the take-offs, performed by the accident pilot." During that flight, an oil smell materialized and they landed to investigate. The CFI reportedly told the accident pilot that he could fly later with him that day, and that he thought that he needed much more than two hours of dual instruction required by the insurance company. The accident pilot, who also has an aircraft mechanic rating, reported that he cleaned the engine with Stoddard solvent and that it was common for the propeller hub to be over serviced with oil, and the excess oil would leak out of the propeller seals. He reported that he drained the oil from the hub and added the correct quantity of oil. The accident pilot/mechanic then ran the engine "for an extended period of time", and did not see any oil leaks. The accident flight was the first flight after the maintenance was performed and the first solo flight for the accident pilot in the airplane. The pilot did not submit a NTSB form 6120.1, Pilot/Operator Accident/Incident Report, as requested.
A loss of engine thrust due to the pilot's inadvertent activation of the propeller controls. Contributing to the accident were the non-standard propeller controls and the pilot's lack of experience in the airplane.
Source: NTSB Aviation Accident Database
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