Abstract: A system and method for providing two-way in-flight radio telecommunications on board an aircraft is disclosed. The radio telecommunication system includes a Gateway Mobile Switching Center (G-MSC), an Aircraft In-flight System Controller (AISC) located on board a subscriber's aircraft, a Ground In-flight System Controller (GISC), a satellite to relay messages and calls from the GISC and AISC, and a Home Location Register (HLR) which provides routing and location information for use by the GISC and the G-MSC. In an alternate embodiment of the invention, a system and method for using a mobile phone on an aircraft is disclosed. A mobile phone is connected to a seat terminal located on an aircraft by a co-ax cable. The radio frequency (RF) signals produced by a mobile phone pass through a coax cable to an Airborne Radio Base Station (A-RBS).