Well, I had no problem using the same IPAD and same configuration setting with the GNS 5870 MFI version.
The IPAD is just the WiFi version (No 3G/4G Sim Card included) and there is no WiFi reception at the airport apron.
This is really strange behavior though. Anyway, I'll stick to the GNS 5870 for now until I find a workaround for this issue.
WP