- Date
- February 29, 1992, 10:22 local (17:22 UTC)
- Place
- Leadville, CO
- Injuries
- 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Enroute
- Aircraft
- N8631EEnstrom TH-28
- Weather
- Visual (VMC) · Day
- Status
- Completed · report July 23, 1993
- Report
- Approved by Office Director
- FAA report
- 19920229017419A
- Case key
- 18198
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 misjudging the descent rate and consequently delaying the flare. A factor was: downdraft.
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
This was one of a series of experimental test flights leading towards FAA certification of the modified helicopter. Data points for the height velocity curve had been collected and the pilot was attempting to confirm their accuracy. At 46 knots and 400 feet AGL, the pilot made an intentional autorotation. He said the sink rate was higher than previously noted, and heavy rotor blade stall made the flare ineffective. The pilot said a downdraft may have precipitated the accident.
Aircraft
- Registration
- N8631E
- Reported as
- Enstrom TH-28
- Category
- Helicopter
- Serial number
- 3003
- Airframe hours
- 575
- Engine
- Allison 250-C20W, 420 horsepower, turbo shaft
- Damage
- Substantial damage
- Flight
- Part 91
- Operator
- Enstrom Helicopter Corporation
- Registered owner
- Enstrom Helicopter Corporation
- Airworthiness certificate
- Special, Experimental (Special)
- Last inspection
- 100 hour · January 20, 1992 · 36 hours before
- Airport
- LXV · Lake County, runway 34, 5,300 × 75 ft, asphalt
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 46
- Certificates
- Airline transport, Flight instructor, Commercial
- Airplane ratings
- Multi-engine land, Single-engine sea, Single-engine land
- Instrument ratings
- Helicopter, Airplane
- Medical
- Class 1, Valid Medical--no waivers/lim.
- Seat
- Right
- Flight hours
- 6,479 total · 889 in this make and model · 5,383 as pilot in command · 97 in the last 90 days · 50 in the last 30 days
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 340° at 5 knots
- Visibility
- 30 statute miles
- Lowest ceiling
- None
- Temperature
- 39 °F, dew point 21 °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.