[Alfonso]

After 3 hours of flight, I used the auxiliary tanks for 30 minutes, which I estimated it used 5 gallons per auxiliary and transferred about 7 gallons surplus fuel to each of the main tanks, leaving about 7 gallons on each auxiliary tank. Is there any procedure or requirement that states that when the auxiliary tanks are used, they have to be used all the way until they are emptied? I landed with a total of 26 gallons of fuel, but I do not like hearing the engine sputtering due to lack of fuel even though there was sufficient. The C336 generally flies with the nose always high about 2 to 3 degrees up, compared with the C337. So when the flaps are extended the wing flies flat relative to the earth, and the fuel in the main tanks spreads to the whole flat tank-wing rather than depositing in the rear of the tank when the nose is up, and where the fuel pick-up pipe is located to send the fuel to the fuel control valve. I remember reading about several years ago of a Skymaster, I do not remember if it was a C336 or a C337, that crashed short of the airport due to fuel starvation even though they apparently have plenty of fuel. Any comments, suggestions, articles, etc would be much appreciated. Thanks.