Bell 47G 4A accident near Gilbert, Iowa, July 24, 2015
On July 24, 2015 at about 11:00 pm local time, a 1967 Bell 47G 4A (helicopter), registered N1396X, was substantially damaged in an accident during maneuvering (low-alt flying) near Gilbert, 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 total loss of engine power due to fuel starvation because the available fuel shifted within the tanks due to an abrupt nose-low maneuver to avoid an obstacle, which resulted in a hard forced landing.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 24, 2015 · about 11:00 pm local time
- Place
- Gilbert, Iowa · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 47G 4A, built 1967 · all 47G 4As on the register
- Registration
- N1396X · registry record · serial 7570
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
The commercial pilot was conducting an aerial application flight. The pilot reported that, while about 150 ft above ground level, he rapidly pitched the nose up to avoid an obstacle and then pitched it nose down to a steep descent angle. When the helicopter entered the nose-low attitude, the engine experienced a total loss of power. The pilot subsequently made a forced landing to a corn field. The pilot reported that he thought the loss of engine power might have been due to the nose-low attitude, which allowed the fuel to shift in the tanks and starve the engine of fuel. He also reported that he never flew the helicopter with less than one quarter of the fuel tanks full (about 15.25 gallons). The helicopter's type certificate holder also noted that, if the helicopter was low on fuel and then put into an abrupt nose-low attitude, the engine could be starved of fuel. During the postaccident examination, 11 to 12 gallons of fuel were drained from the tanks. An engine test run was conducted with no abnormalities noted. Based on the evidence, it is likely that the engine was starved of available fuel due to the rapid and steep descent, which shifted the fuel in the tanks.
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 engine power (total) during maneuvering (low-alt flying)
- Autorotation Hard landing defining event
The NTSB's findings
- cause Aircraft › Aircraft systems › Fuel system › (general) › Capability exceeded
- cause Aircraft › Aircraft systems › Fuel system › (general) › Design
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: helicopter; instructor: instrument airplane; instructor: instrument helicopter; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 6,200 hours in all; 1,200 in this make and model; 15 in the last 90 days; 8 in the last 30 days; 2,600 on instruments
- Last flight review: May 21, 2014
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: ctr
- Injury: no injuries
The aircraft
- Airframe total time: 3,383 hours
- Last inspection: 100-hour inspection, July 1, 2015
- Maximum gross weight: 2,950 lb
- Seats: 1
- Landing gear: fixed
- Engine: Lycoming VO-540 (piston); 0 hours total
- Operator: Fly Right Heli LLC
The flight
- Departed from: Gilbert IA
- Destination: Gilbert IA
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 210° at 8 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 86°F (30°C), dew point 73°F (23°C)
- Altimeter: 29.88 inHg
- Observation at 10:53 pm from KAMW, 7 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
3 documents, released by the NTSB on June 29, 2016. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 2 | FAA Inspector's Statement | PDF, 4 pages | View Download |
| 3 | Photos | PDF, 3 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
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.