Running Aux tanks Dry on Twinco

[ScottB]

I just finished reading my copy of the Comanche Flyer that arrived today. Something that caught my eye was a comment made that running tanks dry on fuel injected is not recommended. Other than the unlikely possibility of the engine quitting entirely and vapor lock preventing restart I cannot think of any reason to avoid this. I have done this with no problems by switching one engine from the nearly empty aux to the nearly full main tank - and leaving the other engine on aux with a few minutes fuel remaining in the tank per the JPI, turned that engines' fuel pump on and kept my hand on the fuel selector and switched it to the main as soon as it surges. Once everything stabilizes I've turned that fuel pump off, turned the other one on, and switched the other engine back to the aux and repeated the process. Anyone care to comment?

[Kristin Winter]

I have run the tanks dry on my Twinkie from time to time. Have done it on other aircraft over the years. No problems, though it does scare the bejeezus out of passengers.

[N3322G]

Scott,

My twin has been in the family since 1970, we regularly run the aux and all but the mains dry. If done with great vigilance by observing the first big fluctuation of the fuel flow pressure, the tanks can be changed with zero engine surge. Note that we only run one tank dry at a time. With three overhauls on two sets of engines, all shops have been complimentary of the engine condition - except when they sat unused during high elder care responsibility.

Even when the engines do surge, we have found no ill effects.

Hope this helps.

[ScottB]

Thanks