On July 31, 1982, a Bell 47J-2 (registration N4070B) operated by Metropolitan Helicopter Inc was involved in an aviation accident near Chesterfield, MO. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During takeoff at 15-20 ft AGL, the pilot heard a loud bang with power loss. An immediate hard landing at about 30 kts forward speed resulted in the tail boom being severed and the right skid collapsing after skidding through a ditch. The engine continued running post-landing and examination found no preimpact deficiencies.
Incident Overview
A helicopter experienced an anomaly during takeoff when the pilot reported a loud bang accompanied by a loss of power while passing through translational lift at an altitude of approximately 15 to 20 feet above ground level (AGL). The pilot initiated an immediate descent and executed a hard landing with a forward speed of about 30 knots.
Pilot Report
According to the pilot, the loud bang and power loss occurred simultaneously. After the hard landing, the helicopter's tail boom was severed, and the right skid collapsed as the aircraft skidded through a ditch. The pilot further stated that the engine remained running after the landing.
Post-Accident Examination
An examination of the engine following the incident revealed no preimpact deficiencies. No other mechanical or structural issues were identified in the available source material.