Robinson Helicopter Company R44 II accident near Charles City, Iowa, July 26, 2023
On July 26, 2023 at about 4:00 pm local time, a 2008 Robinson Helicopter Company R44 II, registered N4174L, was substantially damaged in an accident during prior to flight near Charles City, Iowa. It was an aerial application (crop spraying) flight under general aviation rules (Part 91). 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 of the helicopter to ensure that it was within the loading and performance limitations that resulted in settling and impact with terrain during initial climb.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 26, 2023 · about 4:00 pm local time
- Place
- Charles City, Iowa · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Robinson Helicopter Company R44 II, built 2008
- Registration
- N4174L · registry record · serial 12495
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot of the aerial application flight stated that when the flight returned to the load truck, it still had aerial application product aboard, which he was unaware of. He requested and received an additional 60 gallons of product that was loaded onto the helicopter for the accident flight. After loading the helicopter with the additional product, it now was about 172 lbs over the helicopter’s gross weight. When the helicopter departed from the load truck on the accident flight, the helicopter experienced a decay in rotor rpm and settled into an adjacent corn field about 75 ft from the truck. The helicopter sustained substantial damage to the main and tail rotor blades and tail boom. The pilot stated that he was not properly prepared to jettison the load in the event of an emergency and his power cross checks were not adequate. The pilot stated that there was no mechanical malfunction/failure of the helicopter. An excessive load would have reduced the climb performance capability of the helicopter and resulted in settling.
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 loading event during prior to flight defining event
- Loss of control in flight during initial climb
- Attempted remediation/recovery during uncontrolled descent
- Hard landing during landing
The NTSB's findings
- Personnel issues › Task performance › Planning/preparation › Weight/balance calculations › Pilot
- Aircraft › Aircraft oper/perf/capability › Aircraft capability › Maximum weight › Capability exceeded
Pilot
- Certificate: commercial pilot
- Ratings: instrument: helicopter; rotorcraft: helicopter
- Flight time: 2,057 hours in all; 1,204 in this make and model; 208 in the last 90 days; 189 in the last 30 days; 2,032 as pilot in command
- Last flight review: April 11, 2022
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: frt
- Injury: no injuries
The aircraft
- Airframe total time: 1,913.7 hours
- Last inspection: 100-hour inspection
- Maximum gross weight: 2,500 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming IO-540 (piston); 0 hours total
- Operator: Back Nine Aerial LLC
The flight
- Departed from: West Union IA at 12:00 pm
- Destination: Charles City IA
- Flight plan: none
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 75°F (24°C), dew point 72°F (22°C)
- Altimeter: 29.82 inHg
- Observation at 10:55 am from CCY, 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 October 17, 2023. 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, 11 pages | View Download |
| 2 | Email from Pilot 6120.1 Form | PDF, 4 pages | View Download |
| 3 | Photos | 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 N4174L 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.