The iphone and the 3G iPad have proper gps chips in them. Assisted gps uses your location based on cell sites and wifi to accelerate the lock time when the almanac is out of date. For the gps to work the device can't be in flight mode. I am sat at stanstead typing this on an iPad and can't remember the name of the gps chip set but something is in the back of my mind that it may be infineon.