Don Norris wrote: When I buy the skyGuard TWX and connect it to the iFly 720, and maybe even the iPad mini, which WAAS GPS source will be used for which function? Will the SkyGuard functionally replace the iFly receiver...?
Will I still need to use my external iFly GPS antenna for receiving the GPS signals reliably?
Yes, the SkyGuard will essentially replace the iFly GPS receiver (it will also replace the built-in receiver for tablets, phones, etc.). Thus, you will not *need* to use the external iFly GPS antenna...but you may still want to as a backup. My SkyGuard is in the back of the plane, and I just installed a new power point (cig lighter) in the back for it. Unfortunately, I've learned the hard way that that power point is just a little too close to the tow bar fixtures for comfort; I've managed to jiggle the plug loose a few times and not notice it until I was airborne.
If the iFly loses the signal from an external receiver for any reason (maybe the SkyGuard GPS puck antenna is mounted in a poor location, or it slips out of position during flight and you can't reach to adjust it), it will revert to the internal GPS source. Thus, you may wish to keep that external antenna attached, or at least handy, just in case.