Robinson Helicopter R22 BETA accident near Isabel, South Dakota, April 5, 2012
On April 5, 2012 at about 1:00 pm local time, a Robinson Helicopter R22 BETA, registered N104MH, was substantially damaged in an accident during maneuvering (low-alt flying) near Isabel, South Dakota. It was an other work-use flight under general aviation rules (Part 91). 1 person was seriously injured; 1 other was unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The partial loss of engine power due to carburetor ice.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 5, 2012 · about 1:00 pm local time
- Place
- Isabel, South Dakota · map
- Type
- Accident
- Injuries
- 1 person was seriously injured; 1 other was unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Robinson Helicopter R22 BETA · all R22 BETAs on the register
- Registration
- N104MH · no longer on the register · serial 1843
- Damage
- Substantial damage
- Flight
- Other work-use flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
While maneuvering at low altitude during a coyote hunting operation, the helicopter experienced a partial loss of engine power. The helicopter descended, impacted trees and terrain, and rolled on its right side. There was a minor fuel leak but no postimpact fire. A postaccident examination of the helicopter did not reveal any evidence of preimpact mechanical malfunction or failures that would have precluded normal operation. Based on the temperature and dew point about the time of the accident, the conditions were conducive to serious carburetor icing at any power setting. The pilot reported that he was unsure if he had used carburetor heat for the accident flight. Available evidence suggests that the engine partially lost power in the absence of carburetor heat while operating in conditions conducive to carburetor icing.
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
- Miscellaneous/other during prior to flight
- Abrupt maneuver during maneuvering (low-alt flying)
- Loss of engine power (partial) during maneuvering (low-alt flying) defining event
- Loss of control in flight during maneuvering (low-alt flying)
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
- Roll over during post (impact)
- Landing gear collapse during post (impact)
The NTSB's findings
- cause Environmental issues › Conditions/weather/phenomena › Temp/humidity/pressure › Conducive to carburetor icing › Contributed to outcome
- cause Aircraft › Aircraft power plant › (general) › (general) › Not specified
- Personnel issues › Action/decision › Action › Lack of action › Pilot
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; single-engine land; single-engine sea; instructor: airplane single-engine; instrument: airplane; rotorcraft: helicopter
- Flight time: 11,690 hours in all; 208 in this make and model; 40 in the last 90 days; 20 in the last 30 days
- Last flight review: April 30, 2011
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: rgt
- Injury: serious injuries
The aircraft
- Airframe total time: 6,197 hours
- Last inspection: annual inspection, January 1, 2012; 13 hours since
- Maximum gross weight: 1,370 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming 0-320 SERIES (piston); 0 hours total
The flight
- Departed from: D58 Timber Lake SD at 12:35 pm
- Destination: D58 Timber Lake SD
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 130° at 11 knots
- Visibility: 10 statute miles
- Sky: a few clouds at 3,900 ft
- Temperature: 45°F (7°C), dew point 30°F (-1°C)
- Altimeter: 29.87 inHg
- Observation at 12:52 pm from KMBG, 44 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 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.