NTSB Identification: ATL94LA035.
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Accident occurred Wednesday, December 29, 1993 in MOBILE, AL
Probable Cause Approval Date: 12/02/1994
Aircraft: KAMAN HH-43B/F, registration: N5197W
Injuries: 1 Uninjured.

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 HELICOPTER WAS BEING USED FOR EXTERNAL LIFT, LONG-LINE LOGGING OPERATIONS. AFTER LIFTING A LOAD OF LOGS, THE PILOT EXPERIENCED CONTROL PROBLEMS WITH THE HELICOPTER. THE LOAD, AND THEN THE LONG LINE, WERE JETTISONED, AND AN EMERGENCY DESCENT WAS BEGUN TO THE REMOTE, TEMPORARY LOG HELIPORT. AS THE PILOT ATTEMPTED TO SLOW THE HELICOPTER'S DESCENT RATE, CONTROL WAS LOST. POWER WAS REDUCED, A LEVEL ATTITUDE REGAINED, AND THE MAIN ROTOR BLADES CONTACTED THE GROUND. THE FUSELAGE THEN LANDED HARD. THE WRECKAGE WAS EXAMINED, WHICH REVEALED THAT THE COTTER PIN FOR THE RIGHT ROTOR HEAD TEETER PIN RETAINING NUT WAS ABSENT. ABSENCE OF THE COTTER PIN WOULD ALLOW THE TEETER PIN RETENTION NUT TO LOSE TORQUE, AND EVENTUAL SEPARATION OF THE ROTOR HEAD FROM THE HELICOPTER.

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

AN INADEQUATE MAJOR REPAIR BY COMPANY MAINTENANCE PERSONNEL WHO FAILED TO INSTALL THE COTTER PIN WHICH SECURED THE RETAINING NUT OF THE RIGHT MAIN ROTOR HUB TEETER PIN.

Full narrative available

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