WHAT HAPPENED
I touched down, pushed the throttle forward, and the engine quit.
Fuel basics
Which tank?
Time your switch
Most general aviation aircraft store fuel in the wings. If the fuel supply is lower than the engine, as in a low-wing airplane, fuel must be pumped to the engine—but for high-wing designs such as the Cessna 120, gravity feeds fuel from the wings to the engine. A pilot can control which tank feeds the engine using a fuel selector valve. Although some aircraft have a Both setting that feeds from two tanks at the same time, not all do; and many aircraft draw from tanks unequally, especially if they are slightly out of trim. Try to draw from the two tanks as equally as practical; setting a timer may help you remember when to switch tanks.
The AOPA Air Safety Institute recommends switching tanks on descent before reaching pattern altitude.
In 1946, I was in my junior year as an aeronautical engineering student at Purdue University in West Lafayette, Indiana. I was a rank beginner in Purdue’s flying school. The school trainers were Cessna 120s—two-seat taildraggers with a metal fuselage. The instructors were, for the most part, ex-World War II pilots or students at Purdue. In some cases, my instructor would also be my fraternity brother.
In those days, the Purdue airport was completely grass. Takeoffs could be made east, west, north, or south, depending on wind direction. Most landing approaches were over low fences—except for one that was over a deep quarry. This approach brought you over a steep cliff we were careful to clear with room to spare.
Early in my training, before I had soloed, I was shooting touch and goes with my instructor: coming in high over the quarry, slipping to lose altitude, landing, and then applying full throttle for takeoff.
On this particular day, I was on my third or fourth circuit. I touched down, pushed the throttle forward, and the engine quit.
“Oh, no!” my instructor exclaimed. “I forgot to switch tanks!”
Later, of course, switching fuel tanks would become my responsibility, but at this stage in the training, the instructor still handled that task. He fully realized what the consequences of an engine failure could have been had it happened as we approached the quarry cliff. He continued to berate himself during the balance of my lesson, which emphasized to me how important he considered the oversight.
Although I didn’t fully appreciate what had happened until later, never have I forgotten to switch tanks. Since this episode, I have earned an instrument rating, commercial certificate, and a glider rating.
ASI SAYS
Fuel management is more than simply checking the fuel tanks. You need to confirm your airplane is fueled with the correct grade, check for water or contaminants, and properly manage that fuel during the flight. You also need to know why, when, and how to lean the mixture and calculate fuel burn.
The AOPA Air Safety Institute’s Fuel Management Safety Advisor (www.airsafetyinstitute.org/safetyadvisors/fuelmanagement) can help. The advisor discusses the fueling process; variations in fuel systems; and practical ways to lean the mixture, and predict and recalculate fuel range and endurance. The advisor also provides these suggestions you should incorporate on your next flight: Think of available fuel in hours and minutes, instead of gallons and pounds, and plan on landing with at least one hour of fuel on board to give you a comfortable fuel margin.
Conservative fuel planning provides peace of mind and a buffer to deal with unexpected diversions. Heed ASI’s recommendations, and the odds of a fuel-related incident are slim.
Related Articles
