One thing we should have learned during our primary training is to always have an “out” or backup plan for when things don’t go according to plan. On any given flight, I typically have a smart phone with various aviation apps, an iPad with even more, a mounted Garmin 396 and a handheld radio. I would say most pilots have at least one, if not several of the above. Most of the time, everything in the panel works well and I can fumble my way to the destination without too much assistance from the portable devices surrounding me.But every now and then, we need a little “help.” The need can stem from a failed vacuum/pressure system and unreliable gyros, a total or partial electrical failure or simply a single instrument giving erroneous indications. Without going into too many specifics about hardware, brands and apps, let’s step through what it takes for an appropriate portable or handheld device to be a functional backup in your time of need, something I call “gadget flight rules,” or GFR.