Robinson R44 accident near Okawville, Illinois, July 9, 2018
On July 9, 2018, a 2011 Robinson R44 (helicopter), registered N944DC, was substantially damaged in an accident during takeoff near Okawville, Illinois. 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 improper preflight weight and balance calculation, which resulted in his operating the helicopter over its maximum gross takeoff weight and in its subsequent failure to climb.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 9, 2018
- Place
- Okawville, Illinois · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Robinson R44 II, built 2011 · all R44s on the register
- Registration
- N944DC · registry record · serial 13203
- 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 helicopter pilot reported that, before starting agricultural application flights for the day, he calculated that about 490 lbs of chemical would bring the helicopter's weight near the manufacturer's maximum gross weight limitation. After an agricultural application flight, he landed the helicopter on a platform on top of a chemical reloading truck and reloaded the chemical tank with the precalculated amount. Once reloaded, he maintained a stabilized hover over the truck and transitioned to forward flight. When the helicopter cleared the truck, the "engine [made] a lower sound," and the main rotor low rpm horn activated, and the caution light illuminated. He immediately added power, lowered the collective to restore main rotor rpm, and pitched forward to gain airspeed, but the helicopter would not climb. He then decided to perform a roll-on landing on the adjacent field, but the helicopter landed hard. The helicopter sustained substantial damage to the tail cone, tail rotor blades, and fuselage. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. The pilot added that, after the accident, he recalculated the helicopter's weight and balance. He determined that, during the reloading operation, the chemical tank was not empty but had about 80 lbs of chemical remaining and that the added precalculated amount of chemical exceeded the helicopter's maximum gross weight limitation.
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
- Preflight or dispatch event during prior to flight
- Settling with power/vortex ring state during takeoff defining event
- Attempted remediation/recovery during takeoff
- Collision with terrain or object (not controlled flight into terrain) during takeoff
The NTSB's findings
- cause Aircraft › Aircraft oper/perf/capability › Aircraft capability › Maximum weight › Capability exceeded
- Personnel issues › Task performance › Planning/preparation › Weight/balance calculations › Pilot
- Personnel issues › Task performance › Inspection › (general) › Pilot
Pilot
- Certificate: flight instructor, commercial pilot, private
- Ratings: instructor: helicopter; instructor: instrument helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 1,727 hours in all; 1,064 in this make and model; 181 in the last 90 days; 112 in the last 30 days; 1,655 as pilot in command; 370 on instruments
- Last flight review: May 11, 2018
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: frt
- Injury: no injuries
The aircraft
- Airframe total time: 1,421.5 hours
- Last inspection: 100-hour inspection, July 5, 2018
- Maximum gross weight: 2,500 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming IO-540-AE1A5 (piston); 1,421 hours total
- Operator: Skyline Helicopters Llc
The flight
- Departed from: Okawville IL
- Destination: Okawville IL
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 070° at 4 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 86°F (30°C), dew point 70°F (21°C)
- Altimeter: 30.15 inHg
- Observation at 11:56 pm from KBLV, 14 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.
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.