iFly GPS Forum

If, like me, you have an iFly 740 (or 740b) installed in your airplane, then you may have wished to update it while you're on a trip. I've found that a dual-plug flash drive and a cellphone take care of that problem nicely.

I use a 32 GB SanDisk iXpand Drive and my iPhone. I plug the drive into the phone and use Safari to select and download the update (I get a Custom Update Package). Safari allows me to save the .zip file to the iXpand Drive. When that's done I move the iXpand to the 740 and update from the USB drive. It works just fine.

I haven't tried it in flight, but that ought to work well for a WX update if you have a cell connection, don't mind the 740 not helping with navigation for a few minutes, and have nothing else to do during that time. Updating maps in flight might take longer than you'd want to go without a GPS. But if you have a cell connection, you can use the cellphone as a hotspot, so the 740 can connect to it via wifi. That won't interrupt the GPS display.

I think the 740 will accept USB drives up to 64 GB, but mine won't accept anything larger than that.

No, it's prohibited by the FCC, though I've never heard of anyone being punished for doing it.

The reason the FCC prohibits it is because terrestrial cell networks expect phones to only be in contact with a few towers at a time, and the network can manage those few multiple connections effectively.  In the air, though, a phone might be in contact with dozens or hundreds of towers, which the network is not designed to handle.

If large numbers of phones were constantly doing this, it could compromise the performance of the network.  One or two phones in a small plane won't be a significant issue, though.

Those phones in the small plane might have a hard time maintaining a data connection due to the network confusion, though.