Aviation Accident Summaries

Aviation Accident Summary GAA19CA514

Shamokin, PA, USA

Aircraft #1

N653CH

Hughes 269A

Analysis

The helicopter pilot reported that he was being evaluated for a pilot position with a perspective employer, who was an airplane pilot-rated passenger and occupied the right front seat. He was asked to perform an autorotation as part of the evaluation, and while entering the autorotation, he noticed that the rotor and engine needles were split and that the engine tachometer indicated 0 rpm. He believed that the engine had failed. The pilot maintained the rotor rpm in the green and entered a flare about 40 ft above ground level. He attempted to cushion the landing, but the helicopter landed hard. The pilot reported that he could not hear if the engine was running during the flight because he was wearing a noise-canceling headset. The helicopter sustained substantial damage to the horizontal airframe tube cross-member. During postaccident examination of the helicopter, the throttle linkage functioned normally. All spark plugs were removed and examined and exhibited indications of normal combustion. A fuel sample was obtained through the sump valve, and no water or particulate contamination was found. No evidence of any preaccident mechanical malfunctions or failures were found with the helicopter that would have precluded normal operation.

Factual Information

The helicopter pilot reported that he was being evaluated for a pilot position with a perspective employer, who was a pilot-rated passenger who occupied the right front seat. The pilot in the left seat was asked to perform an autorotation as part of the evaluation, and he complied. During the autorotation entry phase, the pilot noticed that the rotor and engine needles split, and the engine tachometer indicated 0 RPM, and the pilot believed that the engine had failed. The airplane pilot-rated passenger in the right seat, remarked that it was a, "helluva (needle) split." The pilot maintained the rotor RPM in the green and entered the flare about 40ft above the ground. He attempted to cushion the landing, but the helicopter landed hard. When asked during an interview with FAA Aviation Safety Inspectors, the pilot reported that he could not hear if the engine was running because he was wearing a noise canceling headset. The FAA Inspector that performed the post-accident helicopter examination reported that the throttle linkage functioned normally. All spark plugs were removed and examined with indications of normal combustion. A fuel sample was obtained through the sump valve and revealed no indication of water or particulate contamination. According to the FAA Inspector, the wreckage examination failed to identify any discrepancy or malfunction of the airframe, or its components, that would have contributed to the mishap." The helicopter sustained substantial damage to the horizontal airframe tube cross-member.

Probable Cause and Findings

The pilot's improper landing flare during an autorotation, which resulted in a hard landing. Contributing to the accident was a loss of engine power for reasons that could not be determined because postaccident examination revealed no evidence of any preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation.

 

Source: NTSB Aviation Accident Database

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