Misfueled! When Piston Airplanes Are Fueled with Jet A, Bad Things Can Happen by MIKE BUSCH

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OPINION | Misfueled! When piston airplanes are fueled with Jet A, bad things can happen BY MIKE BUSCH

JET A NOZZLES have a duckbill design that should not fit into the restricted-size fueling port of a piston aircraft.

ON MARCH 2, 2008, a turbonormal- left engine sputtered and lost all power. ized Cirrus SR22 was destroyed when Within 30 seconds, the right engine also it crashed shortly after takeoff in Rio lost all power and the big cabin-class twin de Janeiro, Brazil, killing all four peo- descended for a forced landing. The air- ple aboard. Shortly after the aircraft plane landed hard, damaging the wings departed from Runway 20, the engine lost and fuselage and rupturing the right fuel power, and the airplane hit a building and tank, finally coming to rest in the grassy exploded. Further investigation revealed median of a highway. The smell of jet that the aircraft had been refueled with fuel was prominent at the accident scene. Jet A instead of 100LL. Investigators found that the FBO’s Jet A On April 17, 2015, a Cessna 421B crash- truck had recently had its wide duckbill- landed on a highway shortly after takeoff style nozzle replaced with a slim round from Lufkin, Texas, resulting in one seri- nozzle, and that the 421B did not have the ous and two minor injuries. According to fueling port restrictor rings installed per the pilot, the aircraft seemed to perform airworthiness directive 87-21-02 despite normally during the runup, takeoff, and maintenance logs indicating the AD had initial climb. Passing 2,100 feet agl, the been complied with.

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2107p_P&E.indd 96 5/20/21 3:41 PM I had a similar incident in 1992 when The FAA mandated that jet fuel trucks my Cessna Turbo 310 was misfueled with install a wide spade-shaped “duckbill” Jet A at California’s San Carlos Airport, a fuel nozzle, and that vulnerable airplanes FINALLY! busy GA airport just south of San Francisco (like turbocharged twin Cessna) have International Airport. Fortunately, I caught restrictor ports installed into which the A CARD the (mis)fueler in the act. wide jet fuel nozzle would not fit. This Normally, I either fuel my aircraft made misfueling of piston aircraft with FOR PILOTS. myself at a self-serve pump or watch it jet fuel theoretically impossible. (But of being fueled when avgas is supplied by course, it’s also theoretically impossible truck. On this occasion, I’d radioed for for bumblebees to fly.) the fuel truck and waited patiently for it When I arrived at my airplane, I dis- to arrive. After 10 minutes, Mother Nature covered that indeed my left main tank had intervened and required me to go inside been topped with Jet A. How could that the terminal building to find a bathroom. have happened? A subsequent investiga- By the time I took care of my pressing tion by the local flight standards district business and returned to the ramp, a fuel office revealed that the Jet A fuel truck truck was parked by my airplane and a at San Carlos Airport had not been fitted lineperson was pumping fuel into my right with the correct spade-type nozzle. main tank. As I approached the aircraft, I observed to my horror that the truck was THE PURGE prominently labeled “Jet A.” I spent hours trying to find an A&P on the At first, I was not too worried, because field who would assist me in purging the I believed that misfueling my airplane fuel system of its witches’ brew of 100LL 1% Cash Back1 Every Purchase A CASH BACK1 REDEMPTION IS APPLIED AS A STATEMENT CREDIT. When I arrived at my airplane, I discovered that QUARTERLY BONUS POINT CAP OF 2,500 POINTS indeed my left main tank had been topped with Jet A. How could that have happened? Switch today to the AOPA World Mastercard®, and stop paying too much on your aviation purchases. with Jet A was physically impossible. In and Jet A. (This was years before I became 1987, all turbocharged twin Cessnas (like an A&P myself.) The fueling company was my T310R and the 421B) became subject falling all over itself to be helpful—I’m to AD 87-21-02, which mandated instal- sure they were worried about liability— Visit lation of restrictor ports on all fuel filler but had no mechanics or maintenance AOPA.org/creditcard openings, designed to make it impossi- capabilities. Several maintenance shops to learn more. ble to insert an industry standard Jet A were on the field, but none wanted to go nozzle, while accommodating the smaller- near my contaminated airplane for fear of diameter avgas nozzle. the potential liability exposure. Finally, I The AD was issued because the FAA persuaded one director of maintenance to became aware that many misfueling inci- help me out after writing and signing an dents and accidents had been occurring in omnibus waiver absolving his shop and its turbocharged aircraft. Many of these air- employees of any liability in connection *Certain points and purchases restrictions apply, see full Rewards craft were prominently decorated by the with their work on my aircraft. Terms and Conditions for full details at AOPA.org/creditcard. 1. Rewards points can be redeemed for Cash Back or other items pro- factory with the word “Turbo” and appar- The purging process itself was vided through AOPA Pilot Rewards. A Cash Back redemption is applied as a statement credit. The statement credit will reduce your balance ently FBO line personnel were confusing eye-opening. We drained the tanks as but you are still required to make at least your minimum payment. A minimum of 2,500 points is needed to redeem for Cash Back. Values it with “Turbine” and pumping Jet A into completely as possible, putting the nox- for non-cash back redemption items such as merchandise, gift cards, the tanks. ious avgas-Jet A mixture into a 55-gallon and travel may vary.

aopa.org/pilot AOPA PILOT | 97

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drum provided by the fueling company before we were satisfied that the system that a mixture of 100LL and Jet A is also (which had agreed to deal with the was essentially kerosene-free. We recon- blue and that you simply can’t tell the dif- costly disposal of the nasty stuff ). We nected the fuel line and cowled up the ference visually. disconnected the fuel line going to the engine. The fueling company topped off I was also taught that since Jet A is engine-driven fuel pump and drained all the airplane (at no charge). Finally, six significantly heavier than avgas (6.7 ver- the fuel from that as well. hours after the misfueling incident, I was sus 5.85 pounds per gallon), the Jet A and Next, five gallons of 100LL (donated good to go. 100LL will separate just like oil and water by the fueling company) was poured into with the Jet A at the bottom (where the the main tank, pumped through the system TAKEAWAYS sump drain is) and the 100LL at the top. using the electric boost pump, and drained I learned some important lessons that day. That’s true, but only if the contaminated from the disconnected fuel line into a five- Perhaps the most important is that it’s fuel is allowed to sit for hours. It turns out gallon bucket. We tested the fuel in the impossible to distinguish pure avgas and a that 100LL and Jet A mix quite well, and bucket for Jet A contamination by means mixture of avgas and Jet A by color alone. the mixture takes a surprisingly long time of “the paper-towel test.” A few drops My main tanks had been about half full of to separate. were placed on a paper towel and allowed avgas, so after the misfueling they con- I still shudder to think what might to evaporate completely. Pure 100LL will tained roughly a 50-50 mix. If you take a jar have happened had I not spotted that Jet not leave an oily ring on the paper towel, full of pure 100LL and another jar with a A truck in front of my airplane. but even small amounts of Jet A contami- 50/50 mix of 100LL and Jet A, I guarantee There are at least two good ways to nation will leave an obvious ring. The stuff you will not be able to see any difference in distinguish pure 100LL from kerosene- in the bucket flunked the test. color or clarity between the two. contaminated 100LL. One is by odor: Jet Another five gallons of 100LL were I had not realized that before. I was A has a distinctive odor that is detectable poured into the tank, and the process always taught that you sump the tanks and even in small concentrations. The other repeated. Once again, it flunked. We had observe the color—100LL is blue and Jet A (and probably best) is by using the paper- 98 | to repeat the procedure three more times is straw colored. What I was not taught is towel test: Pour a sample on a white paper

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2107p_P&E.indd 98 5/20/21 3:41 PM towel, let it evaporate, and see if it leaves not be noticeable at all. Like so many other an oily ring. things in aviation, it all depends. Think of Jet A as being fuel with a The Cirrus SR22 accident in Brazil and zero-octane rating. Any piston engine the Cessna 421B accident in Texas remind that tries to run on pure Jet A will go into us that the problem of misfueling is still instant destructive detonation. In real life, with us, despite the efforts of the FAA to however, we don’t encounter that situa- eradicate it. As pilots, we need to be vig- tion because our fuel tanks are almost ilant. Always watch your airplane being never completely dry when the aircraft is fueled if you possibly can. Make sure its refueled—or misfueled. fuel filler ports are equipped with restric- The real-world problem is not running tor openings. Don’t just look at the fuel on pure Jet A, but on running on a mix- you drain from your sumps, sniff it—and ture of 100LL and Jet A. Depending on the if there’s any doubt, pour some on a paper mixture ratio of the two fuels, the effective towel. AOPA octane rating can be anything between zero and 100. A mixture with a lot of Jet A and MIKE BUSCH is an A&P/IA. just a little 100LL might be detectable dur- EMAIL [email protected] ing runup. A 50/50 mix might not start to savvyaviation.com detonate until full power is applied, and the engine might fail catastrophically 30 seconds ASK THE A&PS or 3 minutes after takeoff. Just a little Jet A Have a maintenance question? Submit your questions to contamination might produce only moderate JUST BECAUSE THE FUEL LOOKS BLUE doesn’t [email protected]. detonation that might eventually cause spark mean that you haven’t been misfueled with aopa.org/podcasts Jet A. plug nose core insulators to crack or might | 99

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21LYC_Eng-ad_HP_AOPApilot_April.indd 1 2/16/2021 10:27:36 AM

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