On August 30, 1996, a Bell 47-G5 (registration N57RA) was involved in an aviation accident near Riverside, CA. Investigators recorded the probable cause as: The pilot misjudged the aircraft's height above the surface, flared too high, and the helicopter dropped the last 4 or 5 feet. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During a night autorotation practice from 3,000 feet, the pilot misjudged height during flare, leading to a hard landing that severed the tail boom. No mechanical issues were reported.
Accident Details
The accident occurred during a night autorotation landing practice. The pilot was flying from an altitude of 3,000 feet without using the aircraft's landing light, despite it being operational. A full moon provided ground visibility. During the flare, the pilot misjudged the helicopter's height above the surface, flaring too high. The helicopter then dropped the last 4 or 5 feet, resulting in a hard landing with minimal energy remaining in the main rotor. The rotor subsequently severed the tail boom.
Pilot Background
The pilot reported that this flight was to regain night flying proficiency. He had no other night flying time in the previous 90 days. He also stated that no mechanical malfunctions contributed to the event, and that the landing light was available for use had he chosen to activate it.
Findings
The investigation concluded that the hard landing and subsequent damage were due to the pilot's misjudgment of height during the autorotation flare. No other factors were identified.
Probable cause
The pilot misjudged the aircraft's height above the surface, flared too high, and the helicopter dropped the last 4 or 5 feet.