- Date
- August 10, 1991, 20:05 local (Aug 11, 1991, 01:05 UTC)
- Place
- Lake Ozark, MO
- Injuries
- 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Initial climb
- Aircraft
- N61SDBell 47G
- Weather
- Visual (VMC) · Day
- Status
- Completed · report March 9, 1993
- Report
- Approved by Office Director
- FAA report
- 19910810033099A
- Case key
- 15153
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
Failure of the rotorcraft's tail boom in flight. Factors related to the accident were reduced aircraft control available to the pilot.
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 pilot said that shortly after takeoff he heard a loud snap, followed by an uncommanded right yaw. An emergency autorotation was executed which resulted in a hard water landing. Post accident investigation revealed the chromemoly tubing had failed in front of the tail rotor yoke, in flight.
Aircraft
- Registration
- N61SD
- Reported as
- Bell 47G
- Category
- Helicopter
- Serial number
- 3551
- Airframe hours
- 9,065
- Engine
- Lycoming VO-435-AIF, 260 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Business · Part 91
- Operator
- Central Wisconsin Helicopters
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Continuous airworthiness · August 2, 1991 · 15 hours before
- Departed
- Bagnell Dam, MO
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
- 29
- Certificates
- Flight instructor, Commercial
- Airplane ratings
- Single-engine land
- Medical
- Class 2, Valid Medical--no waivers/lim.
- Seat
- Left
- Flight hours
- 1,017 total · 227 in this make and model · 698 as pilot in command · 159 in the last 90 days · 57 in the last 30 days · 7 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 40° at 3 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Observed at
- AIZ, 1 nm away
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.