Phones on Air Force One
It is not necessary to turn off your phone during takeoff on Air Force One, as is the case on commercial aircraft. The President cannot step out of his function for 15 minutes before takeoff or for the duration of the journey.
Souce: Wikimedia
After the plane lost its Internet connectivity in July 2012, President Obama held a conference call to learn about the DOMA judgment. There are also two-way radios, fax machines, 19 televisions, and various office equipment in addition to telephones. Despite being tens of thousands of feet in the air, the President and his team can communicate with everyone on the globe.