On August 3, 1992, a Hughes 369HS (registration N501FH) operated by Coffman, Leslie R. was involved in an aviation accident near Monroe, LA. Investigators recorded the probable cause as: THE PILOT'S FAILURE TO MAINTAIN ADEQUATE ROTOR RPM DURING AUTOROTATION. FACTORS WERE THE TAILWIND AND THE POWER LOSS FOR UNDETERMINED REASONS. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A helicopter suffered a total loss of power during climb at 100 ft AGL. The pilot autorotated but did not maintain rotor rpm, resulting in a hard landing that collapsed the skid gear and severed the tail boom.
Incident Overview
A helicopter engaged in a flight to track the main rotor system experienced a total loss of power during the initial climb. The departure was to the southeast, with winds from the west at 5 knots. At approximately 100 feet above ground level (AGL) and an airspeed of about 35 knots, the engine lost all power.
Autorotation and Landing
The pilot initiated an autorotation to a grassy area abeam a runway. During the flare, the pilot did not maintain adequate rotor rpm. The helicopter subsequently landed hard, causing the skid gear to collapse and the tail boom to separate from the airframe.
Post-Incident Investigation
The engine was removed and test run at the manufacturer's facility, where no anomalies were noted. Additional tests on the engine's related systems were conducted but did not reveal the reason for the loss of power.