The National Transportation Safety Board has determined that misfueling caused the August 21, 2026 crash of a Cessna 421C near Fulton, Kentucky, after both engines lost power during the flight.
The Cessna 421C, registration N28RH, had departed Arkansas International Airport in Blytheville, Arkansas, on a business flight when the pilot noticed that a cylinder on the right engine was running hot. The pilot eventually shut down that engine and feathered its propeller, but the remaining engine then began losing power. Unable to maintain altitude, the pilot made a forced landing in a cornfield near Fulton Airport. Two occupants suffered serious injuries and two suffered minor injuries, and the airplane sustained substantial damage.
We previously reported on the Cessna 421C crash near Fulton, Kentucky shortly after the accident. At that time, the cause of the dual loss of engine power had not been determined. The NTSB’s final report now provides a clear answer: the piston-powered airplane had been fueled with Jet-A instead of the aviation gasoline required by its engines.
The NTSB determined that the probable cause was “the misfuelling of the airplane by the refueler.” The agency also found that the pilot’s failure to verify that the airplane had been properly fueled before departure contributed to the accident.
Cessna Was Filled With 145 Gallons of Jet-A
The investigation traced the engine problems back to the aircraft’s fueling before departure.
According to the NTSB, the airport fueler confirmed that he had topped off the Cessna with “pre-mixed Jet-A.” The airport manager likewise confirmed that Jet-A had been used and provided investigators with a fuel receipt showing that 145 gallons had been added to the airplane. The receipt had been signed by the pilot.
That was the wrong fuel for the aircraft. The Cessna 421C involved in this accident was equipped with two Continental GTSIO-520-L reciprocating engines. Those piston engines require aviation gasoline rather than Jet-A, which is designed for turbine-powered aircraft.
The consequences became apparent after takeoff. The pilot initially noticed that the No. 1 cylinder on the right engine was running hot while climbing. He leveled the airplane at 5,000 feet mean sea level, but the temperature continued to rise. The pilot then shut down the right engine and feathered its propeller while attempting to reach an airport.
The remaining engine subsequently began deteriorating as well. The pilot attempted to increase power, but the airplane could no longer maintain altitude. About two miles from the airport, he was forced to land in a cornfield.
The sequence provides a clear example of how the wrong fuel can produce an engine failure even when the aircraft has adequate fuel aboard. The problem was not that the tanks were empty. They contained a large quantity of fuel that the engines were not designed to burn.
A first responder at the accident scene provided an early indication of the problem. The NTSB reported that fuel taken from one of the airplane’s tanks had no apparent color and smelled like diesel fuel. Aviation gasoline and Jet-A have noticeably different characteristics, making the appearance and odor of the sample important to the investigation.
The final report identifies the wrong fuel as the defining event before the flight and partial loss of engine power as the en route event that followed.
NTSB Also Focused on the Failure to Verify the Fuel Before Takeoff
The NTSB did not end its analysis with the fueler’s mistake. It identified a second failure that allowed the incorrectly fueled aircraft to depart.
During a postaccident interview, the pilot told investigators that he had not specifically instructed the fueler to put 100LL in the airplane. He also acknowledged reading the fuel receipt after the aircraft had been fueled. That receipt showed Jet-A.
According to the report, the pilot explained that they “wanted to get home” and therefore got into the airplane and left. He did not inspect or sample the fuel after refueling.
The NTSB specifically identified that omission as a contributing factor to the crash, concluding that the pilot failed to verify that the aircraft had been properly fueled before departure.
Sampling fuel after refueling serves several purposes. Pilots commonly drain a small amount from the aircraft’s sump points to check the fuel for water, debris, and other fuel contamination. That process also gives the pilot an opportunity to verify that the fuel placed aboard the aircraft is actually the type the engines require.
In this case, the NTSB found that the aircraft left without that verification even though the receipt identified the fuel as Jet-A. The combination of the refueler’s use of the wrong fuel and the missed opportunity to identify the mistake before departure ultimately placed the airplane in flight with two engines operating on an improper fuel.
The accident also illustrates why several independent checks exist in aviation fueling. No single person or procedure has to be the only safeguard. The pilot can specify the fuel grade, the fueler can confirm the aircraft and fuel requirement, placards at the filler ports can be checked, the receipt can be reviewed, and the fuel itself can be sampled before departure. Here, the NTSB concluded that the wrong fuel was delivered and that the mistake was not caught before the airplane took off.
NTSB Warns That Aircraft Misfueling Can Cause Complete Engine Power Loss
The final report includes the NTSB’s safety information concerning prevention of aircraft misfueling. The agency warns that misfueling can occur for several reasons and can result in complete loss of engine power, with the potential for serious injury or death.
One problem identified by the NTSB is that physical safeguards do not always prevent the wrong fuel from entering an aircraft. Aviation gasoline nozzles are normally smaller and round, while Jet-A nozzles are generally larger and shaped differently. Those differences are intended to reduce the possibility of placing jet fuel into an aircraft designed for avgas.
The NTSB has nevertheless encountered situations in which fuel nozzles or aircraft have been modified in ways that defeat those physical protections. Some jet-fuel dispensers use smaller nozzles to service certain turbine aircraft, and some aircraft models can exist in different configurations with different fuel requirements. The agency therefore cautions fueling personnel against relying solely on an aircraft’s appearance or model.
Instead, the NTSB recommends standardized procedures that include confirming the fuel type and quantity requested by the pilot, checking fuel placards, identifying aircraft by registration number, and using the fuel receipt as another opportunity to verify that the correct product was delivered.
The Fulton crash demonstrates the importance of those overlapping checks. The receipt itself accurately recorded that 145 gallons of Jet-A had been placed aboard N28RH. The mistake was therefore documented before the airplane departed, but it was not identified in time to prevent the flight.
For a small plane crash caused by misfueling, determining how the wrong product entered the aircraft requires close attention to the responsibilities of both the fueling operation and the people operating the airplane. The NTSB’s findings in this case expressly address both sides: the refueler selected and dispensed the wrong fuel, while the pilot failed to verify that the aircraft had been correctly fueled before takeoff.
The report does not attribute the accident to weather, an aircraft defect, or an unrelated mechanical problem. Weather at the accident site was visual, with clear conditions and ten miles of visibility. The NTSB instead traced the loss of engine power directly back to the fueling process before departure.
Misfueling Accidents Can Raise Responsibility Beyond the Cockpit
The NTSB’s findings are particularly significant because the probable cause originates with ground servicing rather than an action taken after the aircraft was already airborne.
Aircraft depend on fixed-base operators and other fueling providers to supply the product requested and required for a particular aircraft. Putting turbine fuel into a piston-powered airplane creates a hazard before the engine is ever started. Once the aircraft takes off, the resulting engine problems can leave a pilot with very limited options.
At the same time, the NTSB found that the pilot had an opportunity to detect the error before departure. The signed receipt identified Jet-A, and no post-fueling inspection or fuel sample was performed. The agency therefore treated the pilot’s failure to verify the fuel as a contributing factor rather than the primary probable cause.
Those findings provide a more complete explanation than was available immediately after the accident. What initially appeared to be a double-engine power-loss emergency was ultimately traced to a preventable fueling error followed by a failure to catch that error during the preflight process.
An aviation accident attorney can evaluate the legal issues following an aviation accident involving fueling mistakes, airport service providers, aircraft operators, and other responsible parties. Civil responsibility is determined separately from the NTSB’s safety investigation and depends on the applicable law and evidence surrounding the accident.
The Fulton accident ultimately demonstrates how a mistake made while an aircraft is still parked on the ground can develop into a life-threatening emergency after takeoff. The final NTSB report places the principal cause squarely on the misfueling of the Cessna and identifies the failure to verify that fuel as the additional breakdown that allowed the flight to begin.
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