LAX06LA187 · Hunter Comp Air 6

The airplane descended to ground impact during a forced landing following a loss of engine power during the takeoff initial climb. During the takeoff roll, the engine momentarily hesitated and made a slight "pop" sound. The engine immediately smoothed out and all the cockpit gauges displayed normal indications. After rotation, the airplane climbed to about 400 feet above ground level (agl) and the pilot initiated a turn to the crosswind leg of the traffic pattern. While the airplane was in the turn, the engine experienced a total loss of power. The pilot stated that he attempted to activate the fuel pump and restart the engine, but he was not successful. A witness observed the airplane departing from runway 34. The airplane began to make a 45-degree turn to the west and he noticed that the engine did not sound normal. The airplane appeared to be maneuvering close to the runway and was rapidly losing altitude. After making another 45-degree turn to the left, the airplane was heading south and continually losing altitude. The witness recalled that he did not hear any sound from the airplane's engine. The airplane's left wing dipped down, almost perpendicular to the ground, and then the airplane impacted the terrain. The airplane came to rest inverted. The pilot had recently purchased the airplane and he had acquired 2 hours in the same make and model. The switch for the boost pump was located on the control stick and had three positions: off, low, and high. The post accident examination revealed that the switch was in the high position. According to the previous owner, he found the switch in the high position immediately after the accident. Manual manipulation of the switch revealed that movement was very easy without discernable resistance. During the examination, investigators removed the top spark plugs, which displayed a dark, sooty coloration consistent with a rich mixture setting. Thumb compression was obtained on all six cylinders, confirming crankshaft and camshaft continuity. In addition, the magnetos and their respective ignition harnesses were tested and found to produce a spark in the proper firing order. No anomalies were noted with the engine, with the exception of the dark spark plugs.

Verbatim NTSB analysis and probable cause from the NTSB dataset