If you’re considering purchase of an Apple iPad for aviation applications, you’ve undoubtedly run into confusion about 1) whether iPad has “real” GPS, and 2) whether cellular service must be activated to use it. Here’s the scoop.
First, only the “WiFi+cellular” iPads offer internal GPS capability*. Those models indeed deliver GPS location and groundspeed in the air, georeferenced to VFR and en route IFR charts in Foreflight and similar aviation apps. I know this is true, because I use it.
Secondly, you do not need wireless access or a cellular data plan to navigate via GPS using Foreflight or other EFB applications**. Again, I know this from personal experience.
So why all the confusion about whether cellular network access is required to use iPad’s GPS? Here’s my buddy Rod Machado‘s definitive explanation:
“It turns out that the folks at the Apple store didn’t realize the ultimate capability of the iPad 3G/4G. Here’s what I deduced. It’s true that the iPad 3G/4G has the GPS chips, thus it has a working GPS engine inside. To use that GPS engine with Google Maps [included with iPad], you definitely need an Apple data plan. This is so because you need a way to access the internet to upload those Google maps. On the other hand, with Foreflight, you download 6 Gigs of data/charts that are stored in iPad memory. This allows Foreflight’s data to access the GPS chip and plot the iPad’s true and accurate location on any of Foreflight’s moving maps. So there you have it. When the maps are already stored in the iPad you don’t need any cellular or Wi-fi connection for an accurate moving map display.”
Of course to obtain weather, NOTAMs, or any other online-derived data you indeed need a wi-fi or cellular connection.
Subsequent iPad/GPS updates and user notes:
- Several pilot friends have reported iPads temporarily shutting down due to overheating. (Apple lists max. operating temperature as 95º.) Don’t cook your iPad on your cockpit dash!
- When using the internal GPS, iPad’s geo-referenced aircraft position sometimes shifts a bit on the map when zooming the screen in Foreflight. Clearly this isn’t appropriate for standalone navigation where significant accuracy is required, such as skimming restricted or Class B airspace areas. See this NASA Aviation Safety Reporting System bulletin. (Takes a moment to load.)
- Plug the tiny $99 Bad Elf GPS into your iPad or iPhone to improve GPS performance. (Also adds GPS functionality to wifi-only iPad models.) There’s also a compatible BlueTooth GPS device. See ForeFlight’s explanation.
- **WingX software recommends turning off iPad wireless and cellular service prior to use in flight. This preserves battery life, and most importantly, minimizes the possibility of avionics interference.
- First impressions are that the iPad with Bad-Elf GPS is rock-solid and quite accurate even in my high-wing airplane. No longer does the depicted aircraft position shift on the map with scale changes. Groundspeed and GPS altitude precisely agree with my panel-mounted GPS.
- Be sure to activate Foreflight in your iPad ‘s “location services” preferences or it won’t recognize internal or external GPS. (Settings>General>Location Services>Foreflight.) Mine apparently reset to “off” during the recent OS upgrade. Took a while to figure out why it wasn’t working!
- Read and watch Ian Twombly’s excellent iPad-in-the-cockpit summary. (You may need to be an AOPA member to access this.)
- See MacWorld’s explanation of how iPhone and iPad “assisted GPS” works.
- For more on this topic and much more including apps, see Ruhil’s “Romancing the Air” blog.
©2012, 2017 Gregory N. Brown