NTSB Safety Alert SA-051 - Line Personnel Fueling Matters

Figure 2. Photograph of Jet A fuel nozzle.

Figure 1. Photograph of an avgas nozzle.

Line Personnel: Fueling Matters

Prevent misfueling through standardize d procedures for every aircraft

The problem

Misfueling can occur for a variety of reasons and typically results in a complete loss of

engine power, which may lead to serious injuries and/or death.

• While f uel nozzles and fuel fillers are

designed to prevent misfueling , our

investigations have found numerous

modifications that can allow misfueling to occur . For example, aviation

gasoline (avgas ) nozzles are small and

round and fit into smaller opening fuel

filler ports while jet fuel nozzles are

larger and flattened like a duck’s bill ,

requiring a larger fuel filler port (see

figures 1 and 2) . However, our

investigations have shown that some

fixed base operators (FBOs) are modifying their jet fuel nozzles with the smaller avgas nozzles or other smaller

type nozzle, such as the round jet spout nozzle, to more easily fuel

smaller turbine helicopters. These

non-standard jet fuel nozzles can

easily fit into the smaller filler ports of

aircraft that require avgas and allow for

misfueling to occur .

• When an aircraft is modified from using a reciprocating engine (avgas) to

a turbine engine (jet fuel), some supplemental type certificates (STCs) have not required that the fuel filler port size be changed accordingly . As a result, line personnel have had to make

accommodations such as installing an avgas fuel nozzle or round jet nozzle on a jet

fuel truck to allow jet fuel into the smaller avgas fuel filler port . These STC

SA-051 March 2016 modifications can lead to fueling confusion because the same model or similar

looking aircraft may now have different fuel requirements.

• Once the wrong fuel is pumped into an aircraft , identifying that misfueling has

occu rred can be difficult, if not impossible, to detect.

Related accidents and incidents

The NTSB has investigated accidents involving misfueling, and they show the importance of

pilots and line personnel maintaining vigilance when aircraft are fueled. The following accident summaries help to highlight the issues involved:

• During takeoff , both engines of a Cessna 421C los t power . The airline transport pilot

and two passengers sustained minor injuries in the forced landing. The pilot had

landed the previous night and requested that 40 gallons of fuel be added to each

tank. Line personnel incorrectly fueled the airplane with Jet A fuel by rotating the jet

fuel nozzle and dispensing at a reduced pressure so that the fuel would go into the

avgas fuel port because they had used th is procedure on two other airplanes that had

been modified with turbine engines and were based at the airport. However, t he STC

for the modification did not require that the airplanes’ fuel filler openings be modified

to the standard Jet A nozzle. ( CEN09 LA145

)

• During climbout, a Cessna 421B’s engines lost power. The pilot was seriously injured

and two passengers sustained minor injuries during a forced landing. The pilot had requested that the airplane’s tip tanks be topped off with fuel the day before . The fuel

tanks were placarded for avgas . However, line personnel mistook the airplane for a

similar airplane that required Jet A fuel and refueled it from a Jet A fuel truck that had

been permanently modified with a round nozzle to provide easier access for other aircraft serviced at the airport. The round nozzle also fit the avgas filler port opening

of the Cessna. Before departure, the pilot sumped the fuel and it appeared that the

airplane had been correctly fueled; however, he signed a receipt indicating that the

airplane had been refueled with Jet A. (CEN15LA199

)

• During climbout, the engine of a Canadian -registered Piper PA 46 -350P requiring

avgas lost power , and the pilot was fatally injured during the attempted emergency

landing. A fuel log showed that the airplane had been incorrectly refueled with Jet A

before takeoff. ( WPR15LA111 )

• During the initial climb, both engines of a Cessna 421C lost power . The pilot, two

medical crewmembers, and one patient were fatally injured following impact with

terrain . The pilot had requested that the airplane be refueled with 40 gallons of fuel.

Because the airport also serviced helicopters with smaller opening fuel filler ports that

actually required Jet A fuel, one of the nozzle s on the Jet A fuel truck had been

permanently modified with a round nozzle to provide easier access for these aircraft .

The pilot was present when the line service person incorrectly fueled the Cessna with

Jet A fuel instead of the required avgas . The pilot signed a fuel ticket indicating that

the airplane had been fueled with Jet A fuel. (CEN14FA462 )

SA-051 March 2016 What can line personnel do?

• Ensure that pilots tell you what type of fuel and the quantity are required by their

aircraft then verify that the correct fuel and quantity are being provided.

• Read and verify that fuel placards are correct. If there is a discrepancy between what

the pilot asks for and what is indicated on the placard, ASK! In addition, you can use

a fuel grade verification form signed by the pilot.

• Identify aircraft through the registration number rather than the aircraft make/model.

Due to STC modifications of piston engines to turbines, be aware that even though

you have fueled an aircraft with Jet A, a similar aircraft may require avgas.

Additionally, if your airport services smaller turbine helicopters, the fuel nozzles may have been modified so that the Jet A fuel dispenser is equipped with an avgas nozzle

or round jet spout .

• Many pilots who have had misfueled aircraft have signed receipts that show the

wrong fuel was used. Use the receipt as an added safety check in verify ing with the

pilot that you provided the appropriate fuel.

Interested in more information?

• The National Air Transportation Association provides training through its Safety 1st

General Aviation Misfueling Prevention Program for pilots , line personnel , FBO

general managers, and customer service repr esentatives.

• The Twin Cessna Flyer organization wrote an article, “Misfueling Epidemic ,” in the

August 2015 issue of its magazine that discusses misfueling prevention methods.

• The FAA published Advisory Circular 20- 122A , “Anti-misfueling Devices: Their

Availability and Use .”

• The NTSB made a series of safety recommendations in the 1980s (A -82-140,

A-82-141, and A -86-135) to prevent aircraft misfueling.

The NTSB’s Aviation Information Resources web page, www.ntsb.gov/air , provides

convenient access to NTSB aviation safety products. The reports for the accidents

referenced in this safety alert are accessible by NTSB accident number from the Aviation

Accident Database link, and each accident’s public docket is accessible from the Accident

Dockets link for the Docket Management System . The safety recommendation letters

referenced in this alert can be accessed from the Safety Recommendations link. This safety

alert and others can be accessed from the Aviation Safety Alerts link.