@ Howard and Two......
With the FBW flight controls on these newer planes, there's a lot more than you may understand regarding backup systems and displays.
I also wanna see the report Howard mentioned regarding the F-18 saved with a wristwatch. My handy iPhone GPS app shows groundtrack and speed and such, but I am more interested in speed thru the air molecules. 'course, that iPhone navigation stuff could come in handy if it could update from cell towers of maybe a satellite.