Robinson Helicopter Company R44 accident near Dunlap, Illinois, July 31, 2017
On July 31, 2017 at about 4:19 pm local time, a 2006 Robinson Helicopter Company R44, registered N344MM, was substantially damaged in an accident during takeoff near Dunlap, Illinois. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot’s failure to visually confirm that the helicopter was disconnected from hoses during refueling operations. Contributing to the accident was the pilot’s and ground crew’s misunderstanding of the hand signals.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 31, 2017 · about 4:19 pm local time
- Place
- Dunlap, Illinois · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Robinson Helicopter Company R44 II, built 2006
- Registration
- N344MM · no longer on the register · serial 11280
- 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, after an agricultural flight, he landed on the platform located on top of the truck to refuel the helicopter. The ground crew connected the fuel and chemical hoses to the helicopter. The pilot was taking notes and his focus was inside the helicopter during the connection of the hoses. The pilot reported that he did not expect the chemical hose to be connected to the helicopter. Once the helicopter had the required amount of fuel, the pilot motioned to the ground crew using hand and arm signals that more fuel would be required after the next flight. The driver removed the fuel hose from the helicopter and then stepped back and made eye contact with the pilot. The pilot reported that the ground crew then gave him a "thumbs up" signal. The pilot understood the signal to mean that the helicopter "was clear and safe for departure." The pilot returned the "thumbs up" signal and advanced the throttle. The helicopter ascended, and the pilot noticed the ground crew motioning that the helicopter remained connected to the chemical hose. The pilot observed that the chemical hose was still connected to the helicopter, and he applied aft cyclic. The tail rotor and then the main rotor struck the truck. Per the National Transportation Safety Board Pilot Aircraft Accident Report, the pilot noted that the accident could have been prevented if he had visually confirmed, "with his own eyes, that all possible connecting hoses were in fact, not connected and the departure could be safely executed." 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
- Aircraft servicing event during prior to flight
- Collision during takeoff/land during takeoff defining event
The NTSB's findings
- cause Environmental issues › Physical environment › Object/animal/substance › Ground equipment › Effect on operation
- cause Personnel issues › Action/decision › Action › Lack of action › Pilot
- factor Personnel issues › Task performance › Communication (personnel) › Accuracy of communication › Ground crew
Pilot
- Ratings: single-engine land; rotorcraft: helicopter
- Flight time: 9,199 hours in all; 574 in this make and model; 42 in the last 90 days; 12 in the last 30 days; 9,199 as pilot in command
- Last flight review: April 6, 2017
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: rgt
- Injury: minor injuries
The aircraft
- Airframe total time: 2,906 hours
- Last inspection: annual inspection, August 10, 2016
- Maximum gross weight: 2,500 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming IO-540-F1B5 (piston); 0 hours total
- Operator: Lesco Aircraft Leasing & Sales INC
The flight
- Departed from: C66 Monmouth IL at 12:00 pm
- Destination: C66 Monmouth IL
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: at 5 knots
- Visibility: 10 statute miles
- Sky: a few clouds at 5,500 ft
- Temperature: 81°F (27°C), dew point 61°F (16°C)
- Altimeter: 30.20 inHg
- Observation at 3:54 pm from KPIA, 12 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
2 documents, released by the NTSB on February 27, 2018. 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 | Photo (Courtesy of FAA) | PDF, 1 page | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Other NTSB records under N344MM 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.