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NTSB Report
August 24, 1991 · Bell L4 Experimental L4 Experim · N2770X
Arlington, TX
Overview
Report Status
Probable Cause
Event Type
Accident
Date
August 24, 1991
Injury Outcomes
No injuries (2 uninjured)
Location
Arlington, TX
Aircraft
Bell L4 Experimental L4 Experim
Tail Number
N2770X
Operator
Bell Helicopter Textron
Injuries
None
Aircraft Damage
Substantial
NTSB Number
FTW91LA154
THE FLIGHT TEST PILOT WAS CONDUCTING HEIGHT/VELOCITY MANEUVERS ON THE MANUFACTURERS NEW HELICOPTER. A PLANNED AUTOROTATION WAS INITIATED TO THE RUNWAY. A HARD LANDING OCCURRED, AND A MAIN ROTORBLADE CONTACTED THE TAILBOOM, SEVERING IT. AN EYEWITNESS STATED THE HELICOPTER TOUCHED DOWN ON THE REAR SKIDS AND BOUNCED SEVERAL TIMES BEFORE THE TAILBOOM SEPARATED. NO MECHANICAL FAILURE WAS REPORTED BY THE PILOT.
NTSB Probable Cause
THE PILOT'S FAILURE TO MAINTAIN ADEQUATE ROTOR RPM DURING THE PLANNED AUTOROTATION AND HIS IMPROPER TOUCHDOWN.
Full Narrative
THE FLIGHT TEST PILOT WAS CONDUCTING HEIGHT/VELOCITY MANEUVERS ON THE MANUFACTURERS NEW HELICOPTER. A PLANNED AUTOROTATION WAS INITIATED TO THE RUNWAY. A HARD LANDING OCCURRED, AND A MAIN ROTORBLADE CONTACTED THE TAILBOOM, SEVERING IT. AN EYEWITNESS STATED THE HELICOPTER TOUCHED DOWN ON THE REAR SKIDS AND BOUNCED SEVERAL TIMES BEFORE THE TAILBOOM SEPARATED. NO MECHANICAL FAILURE WAS REPORTED BY THE PILOT.
Flight
Event TypeAccident
Event Time07:59 CDT
Nearest AirportArlington (0nm N)
Runway34
Runway Length4000 ft
Runway Width100 ft
Flight Plan FiledCvfr
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftBell L4 Experimental L4 Experim
Tail NumberN2770X
Aircraft CategoryHeli
DamageSubstantial
OperatorBell Helicopter Textron
Operating RulePart 91
Engines1
Engine TypeTurboshaft
Engine DetailsAllison · 250C30P · Turboshaft · 650
Seats2
People & Injuries
Injury SummaryNo injuries (2 uninjured)
Fatal0
Serious0
Minor0
Uninjured2
Total2
Crew 1Age 44 · Second Class
Conditions
ConditionsVMC
LightDaylight
WindCalm
Visibility10 sm
CeilingNone
Temperature / Dew Point70 F
Altimeter30.00 inHg
Weather SourceWIT