An unusual mission is currently being monitored, as a USAF Boeing WC-135R ‘Constant Phoenix‘ (reg. 64-14836 – c/s JAKE21) has been flying over the Ionian Sea for almost an hour. The aircraft departed from RAF Mildenhall at approximately 7:00 CEST and arrived over the Ionian Sea at around 10:00. The nature of its mission is not known, but this particular aircraft is typically used for non-routine purposes.
The primary purpose of the Constant Phoenix is to collect atmospheric samples for the detection and identification of nuclear explosions. The Constant Phoenix is equipped with specialized modifications, primarily related to its atmospheric collection suite, which enables the crew to detect radioactive debris “clouds” in real-time. The aircraft has external flow-through devices that collect particulates on filter paper, as well as a compressor system for capturing whole air samples in high-pressure holding spheres. Although the C- and W-models have different designations, both carry the same mission equipment, with a front-end avionics suite similar to that of the RC-135V and W aircraft.
The interior of the Constant Phoenix can accommodate up to 33 individuals, including cockpit crew, maintenance personnel, and special equipment operators from the Air Force Technical Applications Center. During operational sorties, the crew is typically reduced to just pilots, navigator, and special equipment operators, in order to minimize radiation exposure to mission-essential personnel only.
UPDATE 14:00 CEST
The aircraft has now headed south, off the coast of Libya, where it is operating at an altitude of 5,000 ft
UPDATE 16:00 CEST
The aircraft continues to fly eastward at the altitude of 6,500 ft