Angier,

You are incorrect about about the iPad WiFi + 3G. It does have a GPS chip, that chip has the additional functionality that Assisted GPS offers. Below is the manufacturer information about the GPS chip that is in an iPad WiFi + 3G.

http://www.broadcom.com/products/GPS/GPS-Silicon-Solutions/BCM4750

Don

On Nov 27, 2010, at 2:43 PM, Greenbacks, UnLtd. wrote:

Hi John,

If you have a need to be online at 20k feet, then the iPad with Wi-Fi and G3 could be one way to go. It has an AGPS chip which allows it to derive position through communication with cell towers only. The G3 model has no dedicated GPS receiver and so is incapable of talking to space vehicles. An iPad with a dedicated external GPS receiver such as http://bad-elf.com/products/gps/ provides considerably greater accuracy and unlike communicating with ground cell towers, is less likely to lose contact with a satellite.
So my math looks like this 499.00 for the least expensive Wi-Fi iPad plus 99.00 for the Bad Elf GPS receiver (I have one), and you're good to go.
The least expensive G3 model is 629.00 plus your monthly connection charges. How much extra do you pay to connect for 12 months?
Either way, just having every approach plate in the entire country on your iPad for the 75.00 annual cost of a Foreflight subscription makes it all worthwhile.

Angier Ames
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