Based on what BigAl07 wrote about maps tiles, I ran a few tests on my Wi-Fi only Samsung Galaxy S2 Tablet. With the Wi-Fi on, I loaded my location maps without scrolling. I shut down the Fly App, turned off the Wi-Fi and then restarted the Fly App. My map tile measured only 500' east and 500' west of my location and 800' north and 800' south of my location. The Map tile was a high-resolution Satellite image, but outside of those distances, there was no satellite image and the street view was little more than streets.
I reran the test, this time I scrolled around for a couple of miles in all directions from my location then I shut down the App, turned off the Wi-Fi and restarted the App. The above rectangle remained high resolution, but for several miles out in all directions, I had a lower level satellite image, enough to distinguish houses, bushes, trees, cars, etc… Not bad, but not the greatest…
So what Big Al says is correct, I guess I'll have to carry my wife's phone as it allows Hot Spotting.
If you do not want to be disturbed by phone calls while flying, you have several options besides going into Airplane Mode which also shut down data…. In setup, turn off vibrate when ringing (I set mine up to vibrate and ring…), and in setup, select Mute, or just turn the volume down so you cannot hear the ringing…
