The French Air and Space Force operate the KC-135 as the C-135FR. Originally ordering 12 aircraft, the C-135F was a custom specification that was intended to be used both as a tanker and cargo transport but also as a troop transport too. Originally the aircraft was only capable of refuelling one aircraft at a time using the boom which is modified to deploy a drogue. Between 1985 to 1988 the fleet were upgraded to C-135FR standard using CFM F108 engines and the installation of wing pods allowing the aircraft to fuel three aircraft at once.