Bell 47G accident near Lake Ozark, Missouri, August 11, 1991
On August 11, 1991 at about 1:05 am local time, a Bell 47G (helicopter), registered N61SD, was substantially damaged in an accident near Lake Ozark, Missouri. It was a business flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
FAILURE OF THE ROTORCRAFT'S TAIL BOOM IN FLIGHT. FACTORS RELATED TO THE ACCIDENT WERE REDUCED AIRCRAFT CONTROL AVAILABLE TO THE PILOT.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 11, 1991 · about 1:05 am local time
- Place
- Lake Ozark, Missouri · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 47G · all 47Gs on the register
- Registration
- N61SD · registry record · serial 3551
- Damage
- Substantial damage
- Flight
- Business flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
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.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: single-engine land; instructor: airplane single-engine; rotorcraft: helicopter
- Flight time: 1,017 hours in all; 227 in this make and model; 159 in the last 90 days; 57 in the last 30 days; 698 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 9,065 hours
- Last inspection: continuous airworthiness programme, August 2, 1991; 15 hours since
- Maximum gross weight: 2,950 lb
- Seats: 3
- Landing gear: fixed
- Engine: Lycoming VO-435-AIF (piston); 0 hours total
The flight
- Departed from: Bagnell Dam MO at 1:05 am
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 040° at 3 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
- Observation at 1:56 am from AIZ, 1 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.