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operating procedure. We assume that sumping thetanks prior to departure is insurance enough againstfueling errors.

That may not always be true, though. The blending oftwo different fuels within the tank can mask the colorand smell distinctions that would normally signify aproblem.Also mistaken is the assumption that a mis-fueled engine will fail to start, or will run poorly. Inmany cases, the engine may seem to run normally forquite some timelong enough to lure the pilot into afalse sense of well-being.

Fueling ChecklistIf you cant rely exclusively upon a preflight inspectionto alert you of problems, what can you do? There area few simple steps that you should follow every timeyou fuel your aircraft:

OrderingWhen ordering, specifically state the fuel grade andquantity you wanti.e., Please top off both tankswith 100LL.

Get a readback of your fuel order from the FBOemployee who took it. Fuel order forms are often color-coded for positiveidentification:Avgas = RED; Jet = BLACK.

Fueling Be present ateach and every refueling of your air-craft. Confirm the specific fuel grade again with theline service professional.Actively observe the fueling process. If somethingdoesnt seem right, speak up immediately.

When we think about the risks associated with avia-tion fuel, the first thing that usually comes to mindis the possibility of a fuel exhaustion incidentanengine failure and subsequent forced landing. Thatconcern is not unwarranted: An average of nearlythree aircraft per week suffer damage due to fuelexhaustion or starvation. Running out of gas is not,however, the only fuel-related worry for pilots.

MisfuelingSimply put, misfuelingis the introduction ofan improper fuel intoan aircrafts tanks.The consequences ofmisfueling can rangefrom the benign (fuelsystem drainage) to

the expensive (enginereplacement) to thedisastrous (engine fail-ure shortly after take-

off). Given simple precautions, all are easily prevent-able.Although the frequency of misfuelings hasdeclined dramatically with the widespread adoption ofcolor-coded wing decals and standardized fuel nozzlesand receptacles, the potential for trouble still existsand, as well see, may increase in the coming years.

Why do misfueling incidents happen? There are manyreasons, but a contributing factor in most incidents is alack of pilot oversight. A recent survey indicated that,while 67% of pilots oversee their airplanes oilchanges, and 50% are present when a tire is aired up,only 39% attend the fueling of their aircraft. While thismay seem surprising at first glance, it makes sensewithin the context of a normal fuel purchase. Thinkabout it: How many times have you landed, jumpedout of the airplane andin a hurry to get goingtoldthe FBO to just top it off? For many of us, its standard

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desirable to do so, but most commercial turbine enginescan be run on avgas within the limits listed in the POH.The inverse is not true. Gasoline engines cannot be run onjet fuel. Without fuel of a certain octane rating, a gasolineengine will be damaged or destroyed by detonation. Jetfuel has no special anti-detonation properties: It will,quite literally, cause a gasoline engine to self-destruct.

During the 1970s and 80s, a rash of misfueling inci-dents prompted the adoption of several safety precau-tions, including color-coded wing and fuel truck decalsand special fuel nozzles and filler openings for jet fuel.Although these steps greatly reduced the misfueling ofgasoline engines with jet fuel, such incidents still needto be eliminated completely.

The recent introduction of diesel engines for generalaviation holds new potential for misfueling trouble. Avi-ation diesel engines are designed to run solely on jet

fuel: Unlike most turbines, they cannot be run safelyon avgas. This is a potentially serious problem, becauseavgas dispensing nozzles fit easily into the large-diame-ter refueling ports used in diesel aircraft. One possiblesolution may be the development of a new selectivefill diesel/turbine refueling port that is incompatiblewith avgas nozzles (Figure 2). Until new measures aretaken, however, owners of diesel-powered aircraftshould be particularly cautious when refueling.

Figure 2: Selective fill

port and jet

fuel nozzle

Safe Pilots. Safe Skies.

Match the fuel truck or fuelisland color-coding with the colorof the wing fueling decal. Thecolor-coding is standardized:Avgas = RED; Jet = BLACK. Check to see that the fuel nozzleis compatible with the aircraftsfuel filler. Avgas nozzles are smalland round (Figure 1), while jet fuelnozzles are larger and flattened likea ducks bill at the end (Figure 2).

PaymentWhen paying, verifythat the fuel grade andquantity on the invoicematch what youordered. Many invoicesand receipts are nowdistinctively marked tofurther identify the fuelgrade delivered.

Preflight Visually check the tanks for quantity and fuel color.Drain a sample from each tank sump. Check forwater and other contaminants, and note the fuelsmell and color. 100LL has a light blue tint, while jetfuel is clear or yellowish in color.

Jet fuel does not evaporate as quickly as avgas, andhas a distinctive, heavier odor. If you haveanydoubts about the type of fuel inyour tanks, DO NOT DEPART.

New ConcernsAny aircraft misfueling is potentially serious, but thegreatest danger for most general aviation pilots occurswhen a gasoline engine is serviced with jet fuel. Its not

Copyright 2005, AOPA Air Safety Foundation421 Aviation Way, Frederick, MD 21701 800-638-3101 www.aopa.org/safetycenter asf@aopa.org

Publisher: Bruce Landsberg Editors: David Wright, Kevin D. Murphy Writer: Brian D. PetersonSB04-07/05

Learn more about fuel safety and other topics by visiting the AOPA Online Safety Centerwww.aopa.org/asf/safety_topics.html

This Safety Brief was produced with the generous assistance of Air BP.

Figure 1:

Avgas nozzle

JET FUEL

ONLY

AVGAS

100LL

Standardized fuel

color-coding