Bell 47G 3B accident near Custer, South Dakota, August 2, 2018
On August 2, 2018 at about 3:20 pm local time, a 1962 Bell 47G 3B (helicopter), registered N347BH, was substantially damaged in an accident during approach near Custer, South Dakota (Crazy Horse Base airport). It was an instructional flight under general aviation rules (Part 91). 1 person had minor injuries; 2 others were unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot’s mismanagement of rotor RPM and subsequent forced landing on uneven terrain which led to a dynamic rollover.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 2, 2018 · about 3:20 pm local time
- Place
- Custer, South Dakota · Crazy Horse Base · map
- Type
- Accident
- Injuries
- 1 person had minor injuries; 2 others were unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 47G 3B No Series, built 1962 · all 47G 3Bs on the register
- Registration
- N347BH · registry record · serial 2771
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The commercial-rated pilot and flight instructor were completing familiarization training in the accident helicopter. After successful training flights the morning of the accident, the flight instructor decided to remove the dual controls from the helicopter, and one additional passenger was loaded before practicing hovering and a low-rpm recovery. On approach to land during the accident flight, about 100 feet above ground level (agl), the pilot noticed the rotor rpms drop below the normal operating range. The pilot increased throttle but was unable to recover rotor rpms within the normal range. The flight instructor stated that the helicopter lost a lot of altitude quickly and there was no time to recover. The pilot attempted a forced landing on the side of a roadway but caught the right skid on uneven ground, which led to a dynamic rollover and substantially damaged the tail section and tail rotor. The flight instructor stated that the engine had no mechanical anomalies before the flight and that the engine had “performed well” during both the accident flight and previous flights. The helicopter likely lost power and altitude due to the pilot’s mismanagement of rotor rpm resulting in the pilot having to attempt a forced landing on uneven terrain and a subsequent dynamic rollover.
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
What happened, in order
- Loss of control in flight during approach defining event
- Dynamic rollover during landing
The NTSB's findings
- Personnel issues › Action/decision › Action › Delayed action › Pilot
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: instructor: helicopter; instructor: instrument helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 1,063 hours in all; 2 in this make and model; 176 in the last 90 days; 86 in the last 30 days; 884 as pilot in command; 245 on instruments
- Last flight review: May 23, 2018
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: left
- Injury: no injuries
Pilot-Rated Passenger
- Certificate: flight instructor, commercial pilot, foreign licence
- Flight time: 1,100 hours in all
- Seat: ctr
- Injury: minor injuries
Passenger
- Seat: rgt
- Injury: no injuries
The aircraft
- Airframe total time: 1,998.1 hours
- Last inspection: 100-hour inspection, January 1, 2018; 47.8 hours since
- Maximum gross weight: 2,900 lb
- Seats: 3
- Landing gear: fixed
- Engine: Lycoming TVO-435D1B (piston); 584 hours total
The flight
- Departed from: OSD9 Custer SD at 3:10 pm
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 320° at 3 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 75°F (24°C), dew point 32°F (0°C)
- Altimeter: 30.07 inHg
- Observation at 8:53 am from KCUT, 405 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 | 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.
Other NTSB records under N347BH the same tail number, which may have belonged to a different aircraft at the time
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number CEN18LA306.