On October 13, 1991, a Bell 47G-5 (registration N1201W) operated by Colony Services, Inc. was involved in an aviation accident near LA Belle, FL. Investigators recorded the probable cause as: THE PILOT IN COMMAND'S IMPROPER AFT APPLICATION OF CYCLIC CONTROL DURING AN AUTOROTATIVE LANDING TO AN OPEN FIELD, RESULTING IN THE MAIN ROTOR BLADES COLLIDING WITH THE TAIL BOOM. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 4 related events involving the same aircraft type or operator are linked below.
A helicopter experienced a loud bang and roaring noise at 200 ft AGL, leading to an autorotation landing that resulted in a hard touchdown and rotor blade contact with the tail boom.
Incident Overview
During cruise flight at an altitude of 200 feet above ground level, the pilot of a helicopter heard a loud bang followed by a roaring noise. In response, the pilot initiated an autorotation descent to an open field. The helicopter touched down in a tail-low attitude, then nosed over and slid forward.
Pilot Statement
The pilot reported that after touchdown, he pulled too much aft cyclic, causing the main rotor blades to collide with the tail boom. The pilot's action contributed to the rotor strike.
Investigation Findings
Examination of the helicopter's systems revealed that the outer bearing of the lower gearcase input quill assembly had failed. The reason for the bearing failure could not be determined during the investigation.