Anything that can go wrong, will, and at the worst possible moment-so states Finagles corollary to Murphys Law. This notion is drilled into pilots from the beginning, so that it becomes second nature to have a plan to handle all sorts of potential failures that could be experienced in flight. Engine failure: check. Instrument and system malfunction: got it covered. Communication failure: no problem. GPS failure... Uhhh, what? Hang on a minute.