" besides falling into the "state the obvious" category completely ignores the fact that air can get into the trap for a lot of reasons, not just cus someone can't tell time. If an airleak in the system, main tank clunk problem or some other malady introduces air into a trap without a bubble-eliminating sock or clunk then the "air eating/flameout-preventing" CAPACITY will be reduced a full 50% in the configuration shown above.

I guess the best money-saving tip here would be to build and maintain your fuel system in such a manner that air does in fact NOT get into the trap - when I land, I never
have more that a small "drop" of air in my hopper tank, if I should ever see that there is more than that, it's about time to go over the system again. If you have a serious
air leak, no hopper tank or UAT can save you from a flame-out for more than a few seconds...

That also goes for all other systems onboard - the air system, batteries, fuel, retracts... build it and maintain it well, and you will save the entire amount that you will loose
if you don't!! Don't accept "a small air leak" in your retract or brake system, don't fly with batteries that are old or worn, don't fly with retracts that fail every 3 or 4 times
you test them, and you will save a lot of money!![8D]

Tor