Never Again: Dry tanks

September 1, 2009

It was a sunny and exceptionally pleasant Saturday morning in late July, and I planned to fly from Memphis to Savannah, Tennessee, to participate in an auction. A 4,000-square-foot Victorian home was for sale along with 150 acres of rolling hills and wooded land overlooking the Tennessee River. Like many pilots, I had a dream of building my own grass strip where I could fly in and enjoy seclusion, relaxation, or river activities with family and friends. The auction also provided an excuse to fly the well-equipped 1979 Cessna 340 twin that two great partners and I proudly owned.

On the way to Memphis International Airport, I used my cell phone to obtain the current and forecast weather for the 100-nm trip, which would normally take about 35 minutes. There was nothing unusual—no fronts, some spotty fog, and the common report of midsummer cumulus clouds later in the day.

As soon as I arrived at the airport, I looked at the aircraft’s previous flight records to assure that there was sufficient fuel left over from the previous flight. The records showed the airplane had been topped off, and then flown for three hours. That left about 1.5 hours of fuel remaining—adequate for my purposes. Just to be on the safe side, however, I decided to add 20 gallons—10 per side in the two main wing tanks. I was planning to top off in Savannah where fuel prices were about 50 cents a gallon lower, so I didn’t want to carry too much fuel.

It was 9 a.m. when I taxied to Runway 27, which happened to be in the opposite direction of my destination. A few minutes later, I was airborne and heading 270 degrees. The gradual climb out to 6,500 feet was beautiful. A few minutes later I was cleared on course eastbound. During the first 50 miles everything was absolutely smooth, and the engines were humming away.

As I was thinking about the auction, I suddenly realized that the terrain below was gradually disappearing. I was soon above a solid layer of low clouds. Where had they come from? The radar showed no convective activity, and the briefer did not elaborate on any changing conditions or mention a need to file an IFR flight plan. Just to be safe, I called Memphis Center and got an IFR clearance. The controllers were glad to help and gave me vectors for a localizer approach. I listened to the AWOS and learned the ceilings were right at the published minimums. I set up for the approach, started my descent, and got into the soup. I was cleared for the approach and established on the localizer. The needle was centered, the wind was negligible, and I leveled off at the minimum descent altitude. I couldn’t see the ground and began executing the missed approach, following the published procedure as I climbed and turned.

That’s when the left engine began sputtering. Cold sweat was my body’s first reaction, followed by an instinctive move to switch the fuel selector valve to the cross-feed position, pointing to the right tank. The engine instantly revived, but by now I was in a 45-degree bank and climbing. My airspeed was rapidly dropping, and ATC was asking my intentions.

Somehow, I understood that I was running out of fuel! The unanticipated fog, the approach, and now the missed approach had exhausted the fuel from the left tank, and now both engines were feeding from the right tank. But how long could that continue? At 20 gallons an hour per engine, I should have at least another 15 minutes remaining. But I had lost my faith in my own calculations. I asked for an altitude of 5,000 feet to get back in the clear and consider my options. I asked for vectors to Jackson, Tennessee, where there was an ILS approach that could safely guide me lower than the localizer. I notified the controller of my low fuel situation but didn’t declare an emergency.

As I was practicing some deep breaths for relaxation, all I could think about was a forced landing with empty tanks and the damage and embarrassment that would come with it. I throttled back both engines and leaned aggressively to burn as little fuel as possible. I also switched to the auxiliary fuel tanks, even though the gauges showed they were nearly empty, to squeeze out every ounce of fuel on board. I was prepared to switch back to the right main tank the moment the auxiliary tanks ran dry.

Jackson was about 20 minutes away, and I soon had to begin descending again into the soup. I expected at any time to lose one or both engines. I scanned the instruments and everything looked good except the fuel gauges, which indicated a fraction above empty. The autopilot did couple to the ILS. I was watching every gauge while scanning faster than usual. The aux tanks were on empty, but the engines were still running. I broke out at 2,200 feet and immediately saw the runway. Short final with gear extended and full flaps. There would be no go-around. I switched the right engine to the right main tank. The touchdown was soft and very relieving. The left engine died as I was taxiing to the ramp and the right engine quit on its own as I was parking. It was now 11:15 a.m., exactly two hours and 15 minutes since I had started the engines. This flight was only supposed to have lasted 30 minutes. And I would have carried more fuel—except that I had hoped to save money by topping off at my destination.

Cessna 340s have rather complicated fuel systems with two main tanks and two auxiliary tanks. I was trained to always land with any remaining fuel in the mains and none in the auxiliary tanks. Thank goodness the previous pilot hadn’t run the auxiliary tanks dry. The remaining fuel in those tanks allowed me to fly to another airport and land safely.

I had sufficient fuel for the trip I planned, but not for contingencies. I had hoped to save some money by buying fuel at my destination, but that almost cost me much more than a tank of avgas.

Nicholas Economides, M.D., is an instrument-rated commercial pilot with more than 1,400 hours of flight experience in single- and multiengine aircraft. He flies a Beechcraft E55 Baron and has been an AOPA member since 1989.