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Losing Them Both – Flying in New Environments

Article appeared in Flying Magazine September, 2015 by John King – John_05

“Hey, fly the airplane.” I looked up, startled to see that we had entered a left bank. At Martha’s urging I came in with strong right rudder, ignored the left boost pump, and flew the airplane to the runway.

The checklist on a Cessna 340 calls for both fuel boost pumps to be switched on at short final. When I did, the left engine quit. There is a principle that says when you do something in an aircraft and you don’t like the result, undo it. Following that principle, I had returned my attention to the left boost pump to turn it back off. Martha rightly had objected to my lack of attention to airplane control.

On the ground we wanted to know—why had the engine quit? We drained the fuel sumps and much to our surprise found water in the fuel. This had us confused. When we had left San Diego for this flight to Cheyenne, we had drained the sumps and found absolutely no water in the fuel. Where had it come from?

We drained the sumps thoroughly, and continued to do so until long after we were no longer getting water. Then we ran the engine up with the boost pump off and on, and it ran just fine. Out of ideas, we took off again. Martha flew us without incident to Sioux Falls, South Dakota.

Our next leg was to Farmington, New Mexico. It was my turn to fly. Everything was fine until, during cruise at 22,000 feet in the pressurized 340, the left engine quit. I switched tanks and the engine came back to life. Again, I was confused. There was plenty of fuel in both tanks.

As we were talking with approach control while setting up for the approach to Farmington, the left engine started surging. Approach control cleared us for the VOR approach to runway 25, circle to land runway 7. Martha said, “You’d better not circle to land.”

I was offended. I was an ATP. I had been trained to fly a twin on one engine. I said, “Why not?” “The other engine is quitting too,” Martha explained. On the panel I could see both fuel flow gauges waving at me. The airplane was yawing back and forth wildly.

I advised approach control that we were making a straight-in to Runway 25 and we were having trouble with both engines. Each engine was putting out intermittent power. I didn’t feather either one of them on the theory that we were getting some power, and that if we feathered them, we would for sure be getting no power.

Farmington’s airport is on a plateau above the town. I wasn’t sure we were going to make it to the runway. If we weren’t going to make it, we would have to make the decision early, or risk slamming into the cliff. I looked for an emergency landing area, but couldn’t find one. The town surrounded the east end of the plateau. I committed us to land on top of the plateau.

We passed over the cliff at less than 50 feet with gear and flaps up. With the runway made, I put them down simultaneously. I idly wondered whether the gear would make it down before we touched down. My biggest concern was whether we would have brakes and steering. I didn’t really care a whole lot whether the airplane would be damaged. I was mad at it at the time—it was letting me down big time.

After landing, we found the left engine had quit completely and the right engine was idling. It produced just enough power to taxi us off the runway and into parking. Firetrucks followed us onto the ramp. One fireman with a clipboard asked, for his report, what the problem was. When I told him I had had problems with both engines, he asked if he could say I was out of fuel. “Absolutely not!” I replied. I pointed out the frost line at mid height on each of the tip tanks caused by the super-cold fuel, explaining it indicated the fuel level.

We left the airplane at a maintenance shop and asked them to investigate the problem. Even though it was only mid-afternoon, Martha and I checked into a hotel for the night.

The next morning the shop told us they couldn’t find any contamination or anything else wrong with the fuel system. I decided to make phone calls. My first call was to Cessna. I made it clear that I was not willing to fly the airplane again until I understood what the problem was, and why it wasn’t going to do that to us again.

The very kind and competent person on the other end of the line said, “It’s not in your model year’s handbook, but in subsequent years there’s an explanation of how to prevent this. When an airplane—even one using avgas—flies at altitudes where it’s very cold, the water that is regularly dissolved in the fuel precipitates out in the form of ice crystals, which then can block your fuel system. Then as your fuel system warms up, the ice melts and the water dissolves back into the fuel. When you drain warm fuel from the sumps, you won’t find water, because it is dissolved in the fuel. The solution is to use a fuel system icing inhibitor like the product called Prist, or isopropyl alcohol.”

I was stunned. This could have been prevented, if we had only known. We went out immediately and bought isopropyl alcohol, and put the recommended amount in our fuel. We used isopropyl alcohol in the fuel from then on and never had the problem again.

We learned from this that we had moved into a new flying environment, and clearly didn’t have the knowledge we needed to identify and mitigate the risks. Our training for flying at higher altitudes had been pretty much limited to a course in an altitude chamber. The rest, things like how to plan our descents and how to keep from shock-cooling our engines, we learned on our own

We took full advantage of the pressurization in the Cessna 340 and routinely flew it in the low twenties. Since our previous aircraft was Cessna 310, our 340 checkouts consisted of little more than a few trips around the pattern. Checkouts in those days were usually pretty minimal. Had we had more formal instruction, we probably would have learned about water dissolving in the fuel—and that alone would have helped us avoid unnecessarily putting our lives at risk.

Interestingly, when we moved into jets we didn’t have any similar problems. In fact it’s fair to say that in 28 years of flying jets we have not had one single “deal,” or in any way scared ourselves in a jet. The reason is that in a jet, in addition to having more redundancy and more reliable systems, we were required by the FAA to have a type rating and the training it requires. We were taught what we needed to know to manage the risks of that particular type of aircraft and the environment it flies in. Along with jet training came the high altitude training we didn’t get for the C340.

Pilots often think of flight training as the learning of physical skills. But our problem at Farmington in the 340 illustrates that getting knowledge is critically important as well. When we pilots move into new environments the FAA often helps us out by requiring specific training such as for seaplanes, gliders and helicopters. But there are many other new environments for which the FAA does not require training, such as mountain flying, off-airport flying, and as in our case, flying at altitudes in the high teens and lower twenties.

From our C340 experience we learned that it pays to use whatever resources you can find to learn about any new flying environment, whether the FAA requires training for it or not. You can look for expert instructors, type clubs, books, courses—any resource that will help you learn about the new environment. The Internet is a powerful tool to use to find these resources. If we had actively sought to learn about the environment of higher-altitude flight, we might have gained the knowledge we needed to identify and mitigate the risk that gave us such a scary experience at Farmington.


  1. Bob Baron

    Finally a reasonable explanation for a problem I had almost 30 years ago. The same thing happened to us except we lost total power and the fuel flow gauges were slamming on and off. We fell 8,000′ before we reached the freezing level and subsequently thawed out. Was able to get 60% power to recover at 2,000′ AGL and land for inspection. No problem found ? Guess an old dog can learn new tricks.


  2. Andreas Kunzi

    What were the temperatures at FL220 on that day?

    Cessna considers icing of the manifolds to be the main problem, so there’s a kit for heated manifolds.

    Filling in (water saturated) fuel at warm places and flying in very cold temperatures thereafter is the worst scenario. Isopropylalcohol is difficult to carry and probably not that safe, so Prist is an alternative. I haven’t seen any airport where they sell IPA right away. Buying the stuff elsewhere also leaves some doubts if there’s really in it what’s written on it. IPA should be added 0.8 to 1 %, Prist 0.12 to 0.15 %.

    I have never heard of anybody using icing inhibitors with AVGAS here in Europe, though.

    On some aircraft, fuel icing was also reported to have disabled tank switching.

  3. David K Campbell

    Fantastic comments, John! A full checkout should really include all that is required for a jet or large aircraft type rating, including climb, cruise, and descent for operating experience.
    David K Campbell
    Airline Transport Pilot, Flight Engineer, Flight Instructor, Aviation Maintenance Tech, BBA Finance, etc.

  4. Michael Frank

    I frequently fly a Mooney 231 in the low flight levels and, thankfully, have yet to experience this type of fuel flow/contamination problem. Nor was I given any information about it when I did my high altitude training. But now I’m wondering if should be adding some alcohol to my 100LL during my winter operations out of New Hampshire.

  5. Ray Bloch Sr

    There have been other article with reference to ice in the fuel at high altitudes but this one is one of the best. One of the other articles pointed out that the ratio of isopropyl alcohol to fuel was 0.1% by volume. In other words the number of gallons of fuel in the tank multiplied by 0.1 % will give the amount of alcohol to be added to the tank.

  6. Alfred Hermitt

    Mr. and Mrs. King, I was very happy to find out that all went well after your c340 engine quit while in flight. The GA industry love you both. I am keeping you both in my prayers.Please stay safe and continue to educate us

  7. Marc Klein

    A less experience pilot might not have asked all the questions you asked and would not have known to put isopropyl alcohol in the tanks

  8. Sherry Richardson

    Although I don’t expect to run into this problem in a Cessna 172; I am passing this along to my CFI.
    Thanks for the advice.
    Sherry Richardson

  9. Tommy Hashim

    I have followed stories about you and your xyl for many years now. I used to fly and have used materials from your school. I am a ham and had been since 1964. My call is DU1TH. I used your training materials to teach and encourage people to learn about amateur radio.
    Today, your story, explained what happened to a friend of mine, while we were in a similar situation. Water in the fuel, that was not there.
    Thank you!

  10. Wes Felty

    Thanks again to the two of you. Your articles are always a fun read but more important, vitally important. In an earlier lifetime I was a Physicist and Chemist but I had never heard of the water coming out of solution like that with temperature. sure that the lower pressure at that altitude had as much to do with the separation as the temperature. It reminds me of how high in the mountains of Wyoming we would hang out our wash in winter, have it freeze solid, and then the water would sublimate when brought into the warm house. Clothes came out dry. But, you had to be high in the mountains to have low enough atmospheric pressure,

    I’m a Sport Pilot so I will never fly that high but I like to collect and spread around knowledge so it’s great to learn something new.

    Keep on keeping on. And, as I heard a wise man say, “Keep the pointy end forward, the dirty side down, and for heaven’s sake ‘Stay out of the trees!'”

  11. Tom Schmitt CFI

    Flying since l947,. Still current (tail draggers). 5yr ago –new rebuild Champ– after hr “testing”–I returned to checkout & re currency the owner& builder. Sod strip surrounded by subdivisions that build into airport area over years. Engine out at 400ft. on takeoff. No place to land. But–just under us 4 lots that had not been built upon. No were else. Wing over and fancy slipping went in OK but totaled new aircraft. Not a scratch on either of us. No panic just mad as hell (share your feeling there). Point is__WHEN GOING DOWN, JUST ACCEPT IT AND DO WHAT YOU HAVE TO DO. FAA found the carburetor float had come apart. (made outside US–NO COMMENT *&%#) . Couple hrs later FAA inspector with hand on my shoulder “Tom, good bit of flying–good job” ( they never do this) . Suddenly i got a bit wet eyed out of delayed shock I guess. FAA comment really helped! Personal experience good learning method but if can, get it from others–do it! Accept what you are dealing with and don’t fight it–as they say “fly to the point of the accident”

  12. Martha Love

    Whew! What a great aviation story. This story kept me on the edge of my seat and was particularly nice since it had a happy ending with some hard learned knowledge from your experience. I’m sending this on to the pilots in my family, so they know about using isopropyl alcohol in the fuel. Thank you for this! Happy Holidays!

  13. Archie San Romani

    Thanks for your story (report)…what is so great about what we do, and, what we learn time after time from students is what makes this “flying stuff” one of the best learning activities.
    Every time I head out to the hangar I “flash back” to “stuff” I was taught back in the late 50’s at Kenmar Air Park, now Jabara Field in Wichita.

    Keep the “good stuff” coming.

    Arch SanRomani, Eugene, OR.

  14. CesarM

    No doubt your life’s work will save yet another soul or two or three. Thanks for the hard earned wisdom! I may never make it to the FLs, but I’ll be sure not to think of flying into even Tahoe for the first time without getting some qualified CFI time.

  15. Jim Zock

    Thanks for the avgas fuel lesson. Fortunately most large jets have fuel heat systems that take care of most of this situation. However, extreme cold also has its issues that British Airways found out at Heathrow when they found their fuel control units iced up when they powered up on approach and unfortunately landed a bit short of the runway. Temp at altitude was minus 70 that day. A lot can be learned from others experiences. Keep them coming.

  16. Jim McCabe

    After reading the article on water/ice in the fuel of a Cessna 340A I felt that I needed to respond. I was operating a 1978 CE-340A Ram IV as a retirement job for a friend. I am a 17,000 +hr semi retired corporate pilot. Most of the time in high altitude jet powered aircraft.
    We experienced the same problem and I took the time, as you, I to searched for an answer. I was able to find a Service Letter from Cessna ME79-2. Dated Feb 16, 1979. It outlines the approved amounts and mixing of isopropyl alcohol to the avgas. Be sure to use a minimum of 99% isopropyl alcohol as anything else uses water as a filler. Also be sure to wait as long as possible ( I waited over night) to drain the sumps thoroughly before flying. The water in the fuel precipitates out of the fuel.
    Hope this helps someone.

    Jim McCabe

  17. John Fernandez

    Excellent article, I am about to make that same transition from props to jets so I will pay attention to the required training , flying at higher levels . Thank you both.

  18. Todd

    Suspended water in fuel has always been an issue when flying at altitudes above the freezing level in the atmosphere. Most GA pilots do not think of this issue because they rarely (except on a cold winters day) fly above a freezing level in the atmosphere. Even if they do, they rarely fly long enough for this condition to develop or exceed the capacity of the fuel strainer in their aircraft.
    Your remedy and preventative measures are right on. If you want to check fuel for this condition, put a sample of fuel (JET, Avgas or AutoGas) in a freezer over night (or on that sub freezing over night-cold soak on the ramp) on view it in a clear GLASS container with a LED flash light. When looking through the fuel sample with the light at varying angles to the container, you can see the suspended crystals the same as looking through a prism. The bright sun light can also work in the correct light and angle to create the refraction of the crystals. My knowledge of this comes from fuel handling in past and I am also an active AP, IA & GA Pilot who has also experienced this circumstance in flight. AutoGas is unique in the fact that most of the products contain some level of alcohol for this vary purpose. Those that do not contain an alcohol product (there are a few premium fuels out there), the same approach should be considered. Jet Fuel is more prone to this condition because of its affinity to hold or suspend very small moisture particles in the fuel volume. Therefore, the Jet Fuel industry puts much effort into stripping (removing) the moisture from the fuel volume in the process of storage, transport, delivery and loading of the fuel into an aircraft. Some prominent brands of fuel add the necessary additives to their fuels to help mitigate any remaining suspend moisture that makes it past the delivery systems. The fuel brands that do not provide this additive in their fuel, would then require the addition of a Prist type product to accompany the fuel load when dispensed. As with most topics, there is a limit to what the additives can manage, but the capacity of the remaining additive in the fuel volume can be tested at the field level by the handlers. Therefore maintaining clean fuel supplies is a daily task, not a reactionary activity to an event. Like most activities in flying, there are numerous topics to manage and consider when prepping for a given flight. A pilot can never have to much knowledge. Acting upon the pilot knowledge or should consider for a given flight is always the demand. Staying aware of ones surroundings before and during the activity is the key to an uneventful flight!

  19. Gordon Barnes

    Hi John: Insightful article. I just acquired a TC Saratoga, I will be educating myself on high altitude flying.

    Gordon Barnes, DDS,MD.

  20. Bassam Massoud

    We are so glad to see both of you safe and sound. This showed us what good pilots both of you are.
    We had a similar situation to yours at 23 thousand feet in C421.
    After that we started to use prist all the times.
    Keep flying safe.

  21. Russell Turner

    This is an excellent article that illustrates that as pilots we must be learning regularly.

    Unfortunately, many pilots, running businesses and working in fields not related to aviation education or flying, avoid continuing aviation education and even regular flying when
    the demands which the businesses or jobs place on their time grows This is where the aviation
    businesses at their home airport can prove most useful by fostering a continuing education program that is enjoyable. They can also provide a knowledgeable co-pilot when it seems prudent.

    It is also the place where pilots who are flying regularly can influence the businessman to join them in recreational flying.

    I miss the old fashioned hangar flying sessions and flying with other pilots in a variety of airplanes. Are they still practiced. Several times in my career, I have avoided an accident or incident through using information I have learned in this informal sharing of information and verification through a little reading. The information always seems to have come close to the time of the potential problem.

  22. L Ligon

    Excellent point and example in an article. As a pilot that has transitioned from a twin Cessna to a jet, I wish I’d known that when I was flying my 421, which is your point.

  23. John Doe

    Good editorial. My biggest takeaway from this is knowing if I ever fly in a plane with John as pilot, I want Martha looking over his shoulder. 😉

  24. John G

    Thank you for sharing this story – very eye opening in regards to the continued need to always be learning and studying. It also clearly illustrates that what is a best practice, a FAA requirement is simply the minimum – you always need to dive deeper if you want to get better!

  25. mike milton

    Mr KING i knew about adding alcohol to keep water from freezing because i drove trucks for over 40 years we had to use it in the fuel tanks. i thought prist was put in as a common fuel additive anyway. also we used kerosene alot because truck diesel would sometimes gel if the temp. stayed below freezing long enough.

  26. William Kelly

    After 39 years of flying myself, I never tire of the stories told by John and Martha King, because each one of them has a valuable lesson behind it. We have all been in situations where others could learn from our own experiences, but few of us have the platform to pass it on. Thank you.

  27. Scott Phillips

    I am confused about the use of isopropyl alcohol, without the qualifier that it is 99.9% isopropyl alcohol. Stuff that does not specifically say 99.9% is by default some part water, which someone not knowing could then accidentally actually introduce water into the system. If we are into educating people let give them all the info we can. Keep up the great column & Happy Thanksgiving.

  28. Charles Wright

    I like your artical and very pertiant to changing environments. But as a chemist I cannot believe the explanation of normally dissolved water. Addition of isopropanol I agree would prevent the icing but would also increase the solubility of water in the fuel. I would not think the aviation fuel if properly managed should have any water dissolved in it as I believe the solubility is essentially zero.

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