While flying in a 310R, if the fuel transfer pump(s) fail (these are the pumps that transfer fuel from the front of the tank to the center of the tank while in a steep descent), how would I know other than the engine(s) quitting ?
Part of a required item of pre-flight is to make sure they’re rattling away with just the battery on. They should both have about the same sound / frequency of pumping sound. If one is distinctly slower than the other, that’s usually a pretty good indication of pending failure.