[Steko]

No, the ring is done by the system while it tries to connect with the target phone. If any cell phone on that plane passed in range of any cell phone tower they would have been able to pinpoint the plane's location fairly quickly.

[nextweek2]

This is an interesting user interface problem. Connecting to a mobile or IP phone can take seconds. As the network operators or phone in question you need to provide feedback that the call is in progress but not ringing at the other end.

Unfortunately there isn't a universal sound for that so you either get silence or a fake ringing. Silence makes people think its broken, whereas ringing gives false hope...