- Date
- August 24, 1991, 07:59 local (12:59 UTC)
- Place
- Arlington, TX
- Injuries
- 2 uninjured
- Damage
- Substantial damage
- Phase of flight
- Landing
- Aircraft
- N2770XBell L4 Experimental
- Weather
- Visual (VMC) · Day
- Status
- Completed · report March 31, 1993
- Report
- Approved by Office Director
- FAA report
- 19910824036669A
- Case key
- 23392
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
The pilot's failure to maintain adequate rotor RPM during the planned autorotation and his improper touchdown.
Sequence of events
NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.
Analysis
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.
Aircraft
- Registration
- N2770X
- Reported as
- Bell L4 Experimental (L4 EXPERIM)
- Category
- Helicopter
- Serial number
- 51022
- Airframe hours
- 3,541
- Engine
- Allison 250C30P, 650 horsepower, turbo shaft
- Damage
- Substantial damage
- Flight
- Other work use · Part 91
- Operator
- Bell Helicopter Textron, Inc.
- Registered owner
- Bell Helicopter Textron, Inc.
- Airworthiness certificate
- Special, Experimental (Special)
- Last inspection
- Unknown · January 2, 2000
- Departed
- 0
- Flight plan
- Company VFR
- Airport
- F54 · Arlington, runway 34, 4,000 × 100 ft, asphalt
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 44
- Certificates
- Commercial, Airline transport, Flight instructor
- Airplane ratings
- Multi-engine land, Single-engine land
- Instrument ratings
- Helicopter, Airplane
- Medical
- Class 2, Valid Medical--no waivers/lim.
- Seat
- Right
- Flight hours
- 11,400 total · 2,138 in this make and model · 8,513 as pilot in command
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- Calm
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 75 °F, dew point 70 °F
- Altimeter
- 30.00 inHg
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.