NTSB Identification: SEA90LA025.
The docket is stored on NTSB microfiche number 41257.
Accident occurred Wednesday, November 29, 1989 in RAYMOND, WA
Probable Cause Approval Date: 06/26/1992
Aircraft: HILLER UH-12E, registration: N9762C
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.DURING AN EXTERNAL LOAD OPERATION, WHILE HAULING A LOAD UPHILL TO THE LANDING ZONE, THE PILOT HEARD A LOUD NOISE AND THE ENGINE BEGAN TO LOSE POWER. THE PILOT RELEASED THE LOAD AND AUTOROTATED TO A LANDING ON INCLINED TERRAIN. WHILE LANDING, THE HELICOPTER ROLLED OVER. DURING AN ENGINE TEARDOWN, A SECTION OF THE IMPELLER WAS FOUND TO HAVE FAILED FROM FATIGUE, WHICH RESULTED IN ADDITIONAL DAMAGE TO THE ENGINE AND A LOSS OF POWER.
The National Transportation Safety Board determines the probable cause(s) of this accident to be:
LOSS OF ENGINE POWER DUE TO FATIGUE FAILURE OF THE IMPELLER. THE HELICOPTER WAS SUBSTANTIALLY DAMAGED AS A RESULT OF A ROLL-OVER ON UNEVEN TERRAIN. Index for Nov1989 | Index of months