Fuel Exhaustion

[Yukon]

Here is story of what is so frequently reported as a Lycoming engine "failure".
Unusual to have such a quick resolution of the cause of the "failure". Probably forgot to lean, didn't look in the tanks, headwinds...........

http://www.ntsb.gov/ntsb/brief2.asp?...08CA042&akey=1

[gmcjetpilot]

John your story not funny but sad and true. However a funny web site:

http://tankonempty.com/

So how long can you drive on 'E'. Looking at the site, +40 miles looks like a typical average, with a min of 20 and max of 80 miles. Some occasionally report 100 miles! Apparently cars made for the American market have more reserve when the E light comes on. In Europe, E means E. It was on 20/20 last week. I'm not recommending it, but I have pulled a "kramer" once or twice in a car. I only really worried about fuel state one time in an airplane. Once was enough.

PS if you think you want to try it, some electric fuel pumps burn out if starved for gas.

[Bob Axsom]

If the pilot saw 1/4 tank in both sides the fuel system and the engine stopped then the fuel system and operating procedures are probably faulty.

The tank gauge calibration is suspect. Was it even done? This is critical any error at the low end of the gauge reading should be fuel remaining that the sender can't float off of the bottom of the resistor range is it is a resistive sender. NEVER should the gauge be accepted as calibrated if it shows 1/4 tank when the tank is empty. If there is a leak, or for any reason the fuel burn is excessive the gauge should reveal the problem.

If the engine stops in flight the first action should be to switch tanks and turn on the aux pump. It the plumbing has been installed to feed off of both tanks at the same time this option is not reliably available and the pilot is probably not managing the fuel - cruising along oblivious to the fuel situation.

I have four tanks but I remove the tip tanks for short races. The tank switch sequence is different with each configuration. My tip tanks only hold 8.5 gallons in each tank. When I am a long cross country I take off on a main and fly for 1/2 hour then switch to the opposite side tip to balance the load for 1/2 hour. My sequence continues other tip, other main for 1/2 hour each then back to the tips (and this is the important part). The tips are now down to 3.5 gallons max with a fuel burn that in normal cruise is 10 gal/hr. I want to use everything in them and know how much I have left in the mains (one more reliable hour in each tank). I allow 18 minutes or a steady drop in fuel pressure which ever comes first and I have my hand on the valve to switch tanks. Often I cannot get the full 18 minutes and before I developed the current operating procedure I had the engine die on occassion. After switching tanks and turning on the aux fuel pump the engine restart takes several seconds with the windmilling propeller. Since I developed that procedure I have never let the engine die. When I am on the last scheduled tank and the engine dies I can still switch to the other main which was supplying fuel to the engine when I made the last scheduled switch. I also keep track of the tip tanks that were still supplying fuel at the 18 minute switch point as emergency reserves. A big point here is if you are actively involved in fuel management you are sensitive to it.

Fuel is a big concern to me because I like to fly as far as I can between stops. However, you have to also consider the possibility in this case that there was fuel on board and it was dumped when the plane was flipped over. If the gauges were properly calibrated and the pilot saw a 1/4 tank of fuel on each side then that is a good possibility regardless of the inspector's findings. If the pilot was operating wide open throttle at maximum RPM the fuel burn is over half again as fast as normal cruise at 75% power.

Bob Axsom