DEN08LA081

The pilot had been practicing maneuvers in preparation to taking his commercial helicopter practical test. At the completion of these maneuvers, he planned on making a normal approach, terminating in a hover. While on base leg and descending through 1,300 feet, the pilot started slowing to 70 knots. He lowered the collective control and reduced power momentarily. When he opened the throttle again, there was no response from the engine. He initiated an autorotation. Shortly thereafter, he heard the engine running and the engine instruments were reading normal. He decided to attempt a landing on the nearby runway. When he increased the collective and applied forward cyclic, the engine lost power again. The helicopter was low and the pilot attempted to slow down by using aft cyclic control. The helicopter then impacted muddy terrain.

On April 18, 2008, approximately 1705 central daylight time, an Enstrom F28C, N56895, piloted by a private pilot, was destroyed when it made a hard landing during an autorotation after the engine lost power during landing approach at Clay County Regional Airport (GPH), Mosby, Missouri. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91 without a flight plan. The pilot, the sole occupant on board, sustained minor injuries. The local flight originated approximately 1630.

According to the pilot's accident report, he had been practicing maneuvers in preparation to taking his commercial helicopter practical test. At the completion of these maneuvers, he planned on making a normal approach, terminating in a hover. While on base leg and descending through 1,300 feet, the pilot started slowing to 70 knots. He lowered the collective control and reduced power momentarily. When he opened the throttle again, there was no response from the engine. "That's when I heard the engine cut out," he said. The pilot initiated an autorotation. Shortly thereafter, he heard the engine running and the engine instruments were reading normal. He decided to attempt a landing on the nearby runway. When he increased the collective and applied forward cyclic, the engine lost power again. The helicopter was low and the pilot attempted slow down by using aft cyclic control. The helicopter then impacted muddy terrain.

In retrospect, the pilot said that after entering the autorotation, he should have completed the maneuver all the way to the ground. Once on the ground, he could then lift the helicopter into a hover to see how then engine would perform.

FAA inspectors who examined the helicopter said they were able to establish fuel continuity from the fuel tank to the fuel injectors. They were unable to determine the reason for the power loss.