NTSB Safety Alert SA-050 - Pilots Fueling Mistakes

Figure 2. Photograph of Jet A fuel nozzle.

Figure 1. Photograph of an avgas nozzle.

Pilots: Fueling Mistakes

Learn how to detect if your aircraft has been misfueled

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 nozzle 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 according ly. 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

SA-050 March 2016 avgas fuel filler port. These STC 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

occurred can be difficult, if not impossible, to detect .

Related accidents and incidents

The NTSB h as 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 lost power. The airline transport pilot

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

previous night and requested 40 gallons of fuel be added to each tank. L ine

person nel incorrectly fueled the airplane with Jet A by rotating the nozzle and

dispensing at a reduced pressure so that the fuel would go into the avgas fuel port

because l ine personnel used this procedure on two other airplanes that were based

at the airport that had been modified with turbine engines . However, t he STC for the

modification did not require that their fuel filler openings be modified to the standard

Jet A nozzle. ( CEN09LA145 )

• During climbout, a Cessna 421B ’s engines lost power. The pilot was serious ly injure d

and two passengers sustained injuries during the 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 one 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 refueled with avgas ; 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 t he 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.

Photographs of the airplane before the accident showed that the fuel tanks were placarded for avgas. 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 airplane was mis fueled with

Jet A fuel instead of the required avgas and signed a fuel ticket indicating that the

airplane had been fueled with Jet A fuel. (CEN14FA462

)

SA-050 March 2016 What can pilots do?

• Always tell line personnel your air craft’s registration number, what type of fuel your

aircraft requires, and which tanks to fuel. Then verify that the correct fuel is being

provided.

• Ensure that your fuel placards are correct , in the appropriate location, and easy to

read. Placards can degrade over time due to environmental exposure.

• Be alert to the fact that line personnel may not be aware of the fueling requirements

of your specific aircraft since STC modifications may replace a reciprocating engine

with a turbine engine. Additionally, if an airport services smaller turbine helicopters,

the fuel nozzles may have been modified so that the Jet A fuel dispenser is equipped

with a n avgas or round jet spout nozzle.

• Although Jet A fuel and avgas have distinct odors, colors, and evaporation properties ,

remember that a visual check alone may not detect that Jet A fuel and avgas have

been mixed. The mixture can appear to be just avgas.

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

wrong fuel was used. Use the receipt as an added safety check in ensuring that your

aircraft was fueled with the correct 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 representatives .

• The AOPA Air Safety Institute’s “Fuel Management ” Safety Spotlight offers safety

education about misfueling, including its “ Misfueling Safety Brief ,” and downloadable

fueling cards (printing charges apply).

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

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

• The General Aviation Manufacturers Association has provided guidance on

appropriate placarding to avoid misfueling and continues to research and work with

industry on the safety issue.

• 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 saf ety recommendation

letter s 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.