Way back in the mid-1980s, when I purchased a 1946 Cessna 120—the same week I earned my private pilot certificate—I received my taildragger checkout from Mr. W.E. Dierking in Higginsville, Mo. “Dirk” had taught U.S. Navy cadets in Waco biplanes during WWII, and he sure taught me a lot about flying! One of the techniques Dirk suggested was to take off with the fuel selector on the left tank (there was no “both” position in the ’46 Cessna), fly for an hour, and write down the time aloft. Then, switch to the right tank and fly until that tank ran dry. As the engine hesitated, switch back to the left tank; you would then know you have the amount of time you’d flown on the right tank minus one hour until you ran out of gas. I never flew the 120 far enough to need this technique, and I never tested my ability to restart the engine after intentional fuel starvation in flight. In recent years, the technique has gained limited but vocal support among personal airplane pundits on the internet and those who follow their guidance.
But was it a good idea? Occasionally this question comes up in seminars I present. Typical pilots tell me the idea of intentionally running a fuel tank completely dry in flight is dangerous and absurd. Dirk also told me to use a chandelle to get out of flying up a blind canyon—a technique with possible merit—and that if you’re VFR only or flying a VFR airplane and are caught on top of a solid cloud deck, that you should enter a spin, spin down through the clouds and recover once you’re in visual conditions below them. That’s perhaps not the best strategy for dealing with that challenge, in my opinion, and two out of three isn’t bad. So just because the old-time pilots apparently ran fuel tanks to engine failure in flight all the time, does that make it the best technique in the modern world? Let’s look at some of the pros and cons of running a tank dry in flight, so you can make an informed decision for yourself.
