NTSB Identification: LAX91LA377.
The docket is stored on NTSB microfiche number 45764.
Accident occurred Saturday, August 31, 1991 in COLEVILLE, CA
Probable Cause Approval Date: 05/03/1993
Aircraft: KAMAN HH43 B/F, registration: N53RH
Injuries: 1 Fatal.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

THE CERTIFICATED COMMERCIAL HELICOPTER PILOT WAS ENGAGED IN A SALVAGE OPERATION OF THE WRECKAGE OF A WORLD WAR II F-4U CORSAIR, UTILIZING AN EXTERNAL 50 FOOT LONG LINE. ON THE FOURTH TRIP OF THE DAY, THE RADIAL AIRCRAFT ENGINE WITH PROPELLERS ATTACHED, WAS BEING LIFTED FROM RUGGED MOUNTAINOUS TERRAIN AT 11000 FEET MSL. THE ENGINE WAS POSITIONED AT THE EDGE OF A ROCKY GLACIAL CHUTE THAT DESCENDED AT ABOUT A 45 DEG ANGLE. THE DENSITY ALTITUDE OF 13000 FEET AND THE EXTERNAL LOAD WEIGHT, EXCEEDED THE PERFORMANCE CAPABILITY OF THE HELICOPTER. AS THE HELICOPTER ATTEMPTED TO LIFT THE ENGINE, GROUND PERSONNEL OBSERVED THE HELICOPTER IN A NOSE DOWN ATTITUDE. THE MAIN ROTOR BLADES STRUCK SURROUNDING TERRAIN. THE HELICOPTER AND ENGINE TUMBLED DOWN THE MOUNTAIN SIDE, DISINTEGRATING AS IT DESCENDED ABOUT 1/2 MILE DOWNSLOPE. ONE GROUND CREWMEMBER RECEIVED MINOR INJURIES FROM FLYING DEBRIS. THE PILOT RECEIVED FATAL INJURIES.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

THE FAILURE OF THE PILOT TO ADEQUATELY CALCULATE THE HELICOPTER PERFORMANCE. CONTRIBUTING TO THE ACCIDENT WAS A DELAY IN JETTISONING THE EXTERNAL LOAD; THE PILOT'S OVERCONFIDENCE IN HIS ABILITIES; AND EXCEEDING OF THE HELICOPTER'S HOVER ABILITY DURING HIGH DENSITY ALTITUDE CONDITIONS.

Index for Aug1991 | Index of months