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NTSB Report
May 7, 1991 · Bell 206B-3 · N717NH
Houston, TX
Overview
Report Status
Probable Cause
Event Type
Accident
Date
May 7, 1991
Injury Outcomes
3 injuries (2 serious injuries, 1 minor injury), 1 unknown outcome
Location
Houston, TX
Aircraft
Bell 206B-3
Tail Number
N717NH
Operator
Southern Belle Helicopters
Injuries
Serious
Aircraft Damage
Destroyed
NTSB Number
DEN91FA068
WHILE ON A FLIGHT OVER METROPOLITAN HOUSTON TO GET AERIAL VIDEO FOOTAGE, THE MAIN DRIVE SHAFT COUPLING FAILED & THE PILOT WAS FORCED TO MAKE AN AUTOROTATION. HE TRIED TO LAND IN A PARKING LOT, BUT WAS UNABLE TO REACH IT. SUBSEQUENTLY, THE HELICOPTER CRASH LANDED ON THE ROOF OF AN APARTMENT HOUSE. AN INVESTIGATION DISCLOSED THE ENGINE MOUNT WAS OIL SOAKED & HAD DELAMINATED, CAUSING MISALIGNMENT OF THE DRIVE SHAFT. ALSO, A LACK OF LUBRICATION WAS NOTED IN THE MAIN DRIVE SHAFT COUPLING. OTHER MAINTENANCE DISCREPANCIES WERE ALSO NOTED DURING THE INVESTIGATION.
NTSB Probable Cause
ENGINE MOUNT DELAMINATION AND LACK LUBRICATION, CAUSING THE DRIVE SHAFT TO FAIL. POOR SERVICING OF THE HELICOPTER WAS A RELATED FACTOR.
Full Narrative
WHILE ON A FLIGHT OVER METROPOLITAN HOUSTON TO GET AERIAL VIDEO FOOTAGE, THE MAIN DRIVE SHAFT COUPLING FAILED & THE PILOT WAS FORCED TO MAKE AN AUTOROTATION. HE TRIED TO LAND IN A PARKING LOT, BUT WAS UNABLE TO REACH IT. SUBSEQUENTLY, THE HELICOPTER CRASH LANDED ON THE ROOF OF AN APARTMENT HOUSE. AN INVESTIGATION DISCLOSED THE ENGINE MOUNT WAS OIL SOAKED & HAD DELAMINATED, CAUSING MISALIGNMENT OF THE DRIVE SHAFT. ALSO, A LACK OF LUBRICATION WAS NOTED IN THE MAIN DRIVE SHAFT COUPLING. OTHER MAINTENANCE DISCREPANCIES WERE ALSO NOTED DURING THE INVESTIGATION.
Flight
Event TypeAccident
Event Time13:10 CDT
Nearest Airport0nm N
Runway0
Runway Length0
Runway Width0
Flight Plan FiledNone
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftBell 206B-3
Tail NumberN717NH
Aircraft CategoryHeli
DamageDestroyed
OperatorSouthern Belle Helicopters
Operating RulePart 135
Engines1
Engine TypeTurboshaft
Engine DetailsAllison · 250-C20B · Turboshaft · 317
Seats5
People & Injuries
Injury Summary3 injuries (2 serious injuries, 1 minor injury), 1 unknown outcome
Fatal0
Serious2
Minor1
Uninjured0
Total4
Crew 1Age 57 · First Class
Conditions
ConditionsVMC
LightDaylight
Wind90° @ 8 kt
Visibility7 sm
CeilingBroken clouds 1400 ft
Temperature / Dew Point70 F
Altimeter30.00 inHg
Observation Time18:50
Weather SourceWFAC