Summary
On July 28, 1992, a Bell UH-1B (N89NW) was involved in an accident near Hayfork, CA. The accident resulted in 1 minor injury. The aircraft sustained substantial damage.
The National Transportation Safety Board determined the probable cause of this accident to be: THE FAILURE OF THE MAIN ROTOR DRIVE SHAFT DUE TO THE IMPROPER INSTALLATION BY COMPANY MAINTENANCE PERSONNEL OF AN 'O' RING SEAL, WHICH ALLOWED THE PACKING GREASE TO ESCAPE AND CAUSED THE OVER TEMPERATURE FAILURE OF THE DRIVE SHAFT. A FACTOR IN THE ACCIDENT WAS THE LACK OF SUITABLE TERRAIN IN WHICH TO PERFORM AN AUTOROTATION.
This accident is documented in NTSB report LAX92LA319. AviatorDB cross-references NTSB investigation data with FAA registry records to provide comprehensive safety information for aircraft N89NW.
Accident Details
Probable Cause and Findings
THE FAILURE OF THE MAIN ROTOR DRIVE SHAFT DUE TO THE IMPROPER INSTALLATION BY COMPANY MAINTENANCE PERSONNEL OF AN 'O' RING SEAL, WHICH ALLOWED THE PACKING GREASE TO ESCAPE AND CAUSED THE OVER TEMPERATURE FAILURE OF THE DRIVE SHAFT. A FACTOR IN THE ACCIDENT WAS THE LACK OF SUITABLE TERRAIN IN WHICH TO PERFORM AN AUTOROTATION.
Aircraft Information
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# LAX92LA319