Boeing C-135FR

5 aircraft

The WC-135 Constant Phoenix, a specialized atmospheric sampling aircraft, serves as the United States Air Force's primary platform for nuclear treaty verification and weather reconnaissance missions. First converted from existing Boeing C-135 airframes in 1965, it is a four-engine turbofan aircraft capable of flying through radioactive clouds to collect atmospheric samples and meteorological data. With a maximum takeoff weight of 300,500 pounds and powered by Pratt & Whitney TF33 or General Electric F108 engines, the aircraft operates with a crew of four or more personnel. The WC-135 was manufactured through conversions by Boeing from their C-135 Stratolifter and KC-135 Stratotanker platforms.