Amateur-built CX4 accident near Marshalltown, Iowa, September 9, 2021
On September 9, 2021 at about 5:45 pm local time, a 2008 amateur-built CX4, registered N306TA, was substantially damaged in an accident during approach near Marshalltown, Iowa (Marshalltown Municipal Airport). It was a personal flight under general aviation rules (Part 91). 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 properly determine the correct fuel quantity during preflight inspection that resulted in a loss of engine power during approach due to fuel exhaustion.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 9, 2021 · about 5:45 pm local time
- Place
- Marshalltown, Iowa · Marshalltown Municipal Airport · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built CX4, built 2008
- Registration
- N306TA · no longer on the register · serial CX159
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot stated that he visually inspected the airplane fuel quantity before the flight and estimated there was 6 gallons of fuel. He said there was enough fuel for the planned flight with a fuel consumption rate of 3.5 gallons/hour. After he flew to an airport to perform a touch-and-go landing, in addition to local area flying, he began a return flight to the departure airport. He then realized that the airplane fuel quantity gauge indicated a fuel consumption that was greater than he had planned. About 3 miles from the departure/destination airport, the fuel gauge indicated near empty, and the engine ceased operation. He said he restarted the engine, which operated for about 5 seconds and then quit again. The pilot performed a forced landing on a corn field, during which the airplane nosed over. The airplane sustained substantial damage that included damage to the fuselage, empennage, and both wings. The pilot said the loss of engine power was due to his overestimation of fuel quantity during his preflight of the airplane and the inaccuracy of the fuel gauge. The pilot said there was no mechanical malfunction or failure of the airplane that would have precluded normal operations.
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
- Fuel exhaustion during approach defining event
- Loss of engine power (total) during emergency descent
- Loss of engine power (total) during approach
- Attempted remediation/recovery during approach
- Aircraft inspection event during prior to flight
- Off-field or emergency landing during landing (flare/touchdown)
The NTSB's findings
- Aircraft › Fluids/misc hardware › Fluids › Fuel › Fluid level
- Aircraft › Aircraft systems › Fuel system › Fuel indication system › Related operating info
- Personnel issues › Task performance › Inspection › Preflight inspection › Flight crew
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 242 hours in all; 80 in this make and model; 18 in the last 90 days; 3 in the last 30 days; 219 as pilot in command
- Medical certificate: Sport Pilot
- Seat: sngl
- Injury: minor injuries
The aircraft
- Airframe total time: 359 hours
- Last inspection: condition inspection, September 19, 2020
- Maximum gross weight: 850 lb
- Seats: 1
- Landing gear: fixed
- Engine: Revmaster 2100D (piston); 410 hours total
The flight
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 290° at 6 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 72°F (22°C), dew point 54°F (12°C)
- Altimeter: 30.07 inHg
- Observation at 11:53 am from MIW, 2 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 October 14, 2021. 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 | Aircraft Wreckage Photo | 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.
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.