Bell 47G 3B accident near Toterville, Iowa, July 24, 2017
On July 24, 2017 at about 9:00 pm local time, a 1961 Bell 47G 3B (helicopter), registered N47AH, was substantially damaged in an accident during maneuvering (low-alt flying) near Toterville, Iowa. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 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
The pilot’s failure to maintain rotor rpm while maneuvering at low altitude with low airspeed and a tailwind.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 24, 2017 · about 9:00 pm local time
- Place
- Toterville, Iowa · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 47G 3B 3B, built 1961 · all 47G 3Bs on the register
- Registration
- N47AH · registry record · serial 2645
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
According to the helicopter pilot, during an agricultural flight, he made a downwind turn to spray the intended field. During the low airspeed right turn, he increased the engine power, and the rotor rpm decreased. He reported that he leveled the helicopter to clear power lines, but the rotor rpm remained low. The helicopter descended, and the pilot landed the helicopter in a corn field. The helicopter sustained substantial damage to the tailboom and horizontal stabilizer. The nearest METAR located 15 nautical miles south-southeast from the accident site reported that, about the time of the accident, the wind was calm. The pilot reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation.
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 maneuvering (low-alt flying) defining event
- Off-field or emergency landing during maneuvering (low-alt flying)
The NTSB's findings
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
- cause Environmental issues › Conditions/weather/phenomena › Wind › Tailwind › Effect on operation
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Prop/rotor parameters › Not attained/maintained
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Airspeed › Not attained/maintained
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Altitude › Attain/maintain not possible
Pilot
- Certificate: private
- Ratings: single-engine land; rotorcraft: helicopter
- Flight time: 389 hours in all; 1 in this make and model; 150 in the last 90 days; 100 in the last 30 days
- Last flight review: April 13, 2017
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 14,259 hours
- Last inspection: annual inspection, May 1, 2017
- Maximum gross weight: 2,850 lb
- Seats: 1
- Landing gear: fixed
- Engine: Lycoming TV0-435 SER (piston); 0 hours total
- Operator: Scotts Helicopter Service INC
The flight
- Departed from: Toterville IA at 6:50 am
- Destination: Toterville IA
- Flight plan: none
Weather at the time
- Light: daylight
- Visibility: 7 statute miles
- Sky: clear
- Temperature: 57°F (14°C), dew point 55°F (13°C)
- Altimeter: 30.03 inHg
- Observation at 8:14 am from KAUM, 15 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight 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.
Other NTSB records under N47AH the same tail number, which may have belonged to a different aircraft at the time
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.