Despite suffering hydraulic failure, the WC-135 ‘Constant Phoenix’ landed safely at RAF Mildenhall in the UK after a patrol over the Baltic Sea yesterday evening.
You can listen to the emergency declaration recorded by Twitter user @EHEH_Spotter by clicking the video below. I recommend you follow them for more.
— ''The Lazy 🌴 Garden 🌴'' Eindhoven Spotter 🇳🇱 (@EHEH_Spotter) February 22, 2022
The aircraft arrived in the UK recently and has been operating out of RAF Mildenhall.
🚨 NEWS | An American aircraft designed to 'sniff' radioactivity associated with nuclear material, a WC-135 'Constant Phoenix', declared an emergency whilst returning to the UK after a patrol over the Baltic Sea yesterday evening. pic.twitter.com/JK68KtfpMn
— George Allison (@geoallison) February 23, 2022
Previously, air sampling missions were routinely conducted over the Far East, Indian Ocean, Bay of Bengal, Mediterranean Sea, the Polar regions, and off the coasts of South America and Africa. The aircraft doesn’t usually stay in a region for too long before heading back to the United States.
More notably, back in 2017 an aircraft was deployed to RAF Mildenhall to conduct missions over Europe after air quality stations across the continent detected traces of radioactive Iodine-131.
The aircraft has been sued previously to trace radioactivity from Russian submarines.
Historically, the WC-135W fleet played a major role in tracking radioactive debris from the Soviet Union’s Chernobyl nuclear plant disaster.
What is the WC-135W?
The WC-135 ‘Constant Phoenix’ is U.S. Air Force a special-purpose aircraft derived from the Boeing C-135 Stratolifter (as also with the RC-135 ‘Rivet Joint’ signals intelligence aircraft used by the Royal Air Force).
According to the U.S. Air Force, its mission is to collect samples from the atmosphere for the purpose of detecting and identifying nuclear explosions.
According to military.com here, the Constant Phoenix has an on-board atmospheric collection suite, which allows the mission crew to detect radioactive “clouds” in real time. The aircraft is equipped with external flow-through devices to collect particulates on filter paper and a compressor system for whole air samples collected in holding spheres.