NTSB Identification: FTW85FA310.
The docket is stored on NTSB microfiche number 31474.
Accident occurred Thursday, August 08, 1985 in ST. JAMES, LA
Aircraft: BELL UH-1B, registration: N1385W
Injuries: 1 Fatal.
NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.
ACFT WAS AT A 150' HOVER PREPARING TO PICK UP A LOG WHEN IT EXPERIENCED A POWER LOSS. WITNESSES STATED THAT THEY HEARD A LOUD 'BANG' AND THE PILOT RADIOED 'GET OUT OF THE WAY'. ACFT AUTOROTATED THRU 60' TO 80' TREES WITH VERY LOW ROTOR RPM AND IMPACTED WITH NO HORZ SPEED AND HIGH VERTICAL SPEED. INVESTIGATION REVEALED THAT ENG HAD EXPERIENCED SEVERE INTERNAL DAMAGE. FOUR COMPRESSOR BLADES FROM THE 4TH STAGE ROTOR WERE FOUND TO HAVE SUFFERED PROGRESSIVE FATIGUE FAILURE, WHICH IN TURN CAUSED THE REMAINDER OF THE BLADES ON THE 4TH AND 5TH STAGES TO SEPARATE LEADING TO AN ENG SURGE AND LOSS OF POWER. THE ACCIDENT OCCURRED IN A FLT REGIME FROM WHICH THE PLT COULD NOT AFFECT A RECOVERY FROM THE ENG FAILURE.
The National Transportation Safety Board determines the probable cause(s) of this accident to be:COMPRESSOR ASSEMBLY,BLADE..FAILURE,TOTAL
The National Transportation Safety Board determines the probable cause(s) of this accident to be:ROTOR RPM..NOT POSSIBLE..PILOT IN COMMAND
The National Transportation Safety Board determines the probable cause(s) of this accident to be:COMPRESSOR ASSEMBLY,BLADE..FATIGUE
TERRAIN CONDITION..NONE SUITABLE
TERRAIN CONDITION..HIGH VEGETATION
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