CEN20LA149

The pilot reported that he had just taken off and retracted the landing gear when the airplane experienced a substantial loss in engine power. He retarded the throttles to idle and landed the airplane on the remaining runway without lowering the landing gear, resulting in substantial damage to the rear spar caps. Both propellers were found in a feathered position although the pilot said he did not feather them. It is unlikely that the propellers feathered on their own, as the propeller control levers must be placed in the feathered position to feather them; however it could not be determined when the propellers were feathered. Postaccident examination revealed a small amount of water in the fuel selector sump bowl and left auxiliary tank sump bowls but not elsewhere in the fuel system. Thus, it is unlikely that the water found would have affected the performance of the engine. Subsequent engine runs on each engine using the same fuel that was onboard the airplane at the time of the accident revealed no anomalies and normal propellers cycles. No reason for a partial loss of engine power on either or both engines could be determined based on available evidence.

On April 13, 2020, a Cessna 402B, N98649, was substantially damaged when it was involved in an accident at Kirksville Municipal Airport (IRK), Kirksville, Missouri. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 135 on-demand cargo flight. The pilot reported that he was taking off and everything appeared normal until shortly after the airplane lifted off, and the pilot established a positive rate of climb and initiated the retraction of the landing gear. He said that as the landing gear retracted there was a substantial loss in engine power that resulted in an inability to maintain a positive rate of climb. He did not recall looking at the engine instruments and could not verify if there was a loss of power in a single engine or both engines. The pilot said he retarded the throttles and landed on the remaining runway without extending the landing gear, resulting in substantial damage to the rear spar caps. He said that he did not feather the propellers. He said he "shut down all systems and exited the plane" after it came to a stop. The pilot stated that the airplane was refueled the day of the accident; he had sumped the fuel system during his preflight inspection and found no contaminants. The fuel capacity was 163 gallons without the locker fuel tanks refueled, which were not used according to the pilot. The operator and pilot both reported that there were 163 gallons of fuel onboard the airplane. The pilot took off with the main fuel tanks selected. A Federal Aviation Administration (FAA) inspector conducted an examination of the airplane with the assistance of an aircraft mechanic. Both the left and right engine propellers were found in a partially feathered state as the airplane rested on the runway and both fuel selector valves were found in the off position. The fuel selectors had positive detents at each commanded tank position. The right and left fuel selector sump bowls were removed and samples of liquid consistent with aviation fuel was recovered. The samples from both sump bowls contained a small amount of brownish liquid consistent with water. A small amount of liquid consistent with water was also found in a fuel sample from the left auxiliary fuel tank sump. No water was found in the remainder of the fuel system. Compression and continuity of both engines was verified by removing a spark plug from each cylinder and rotating the propeller through the compression stroke while covering the spark plug holes. Each magneto was examined and verified to produce proper spark. Throttle, mixture, and propeller controls were verified to move freely and properly. The fuel line was removed from the fuel spider and the electric fuel pump operation was verified at both the Hi and Low positions for both engines, and the fuel line was reconnected. Engine runs were subsequently completed on both the left and right engines under the supervision of an FAA inspector using a substitute propeller.Both engines were started and ran to full power utilizing the airplane's systems and fuel from the airplane's main fuel tanks, which was the same fuel onboard the airplane at the time of the accident. Both propellers cycled normally during the preflight routine and no anomalies were noted during either engine run. The pilot's operating handbook states "To feather the propeller blades, the propeller control levers on the control pedestal must be placed in the feather position."