The WC-135R Constant Phoenix was deployed to the Middle East for atmospheric testing, and, in a rare move, the U.S. Air Force publicly acknowledged the mission.
Photos released by U.S. Air Force Central through the DVIDS network, confirm that the WC-135R 64-14831 was recently deployed to the Middle East for what the captions call an atmospheric testing. The presence of the Constant Phoenix platform in the region had been revealed by means of ADS-B, as the aircraft carried out its missions out of Al Udeid, Qatar, and Diego Garcia, in the Indian Ocean.
***Repost***
Constant Phoenix 64-14831 as Atom-31 on a return flight to Diego Garcia. It relocated to Al Udeid Nov 28th and flew one sampling mission over the Persian Gulf and Gulf of Oman on Dec 1st.
I had Guam on the brain this morning, wrong side of the world is all…..🤦♂️ pic.twitter.com/qkJI3FzYkn
— MeNMyRC (@MeNMyRC1) December 2, 2024
Finally some tracking on the Constant Phoenix at Diego Garcia. 64-84131 as Panda-22 is Northbound toward the Western Coast of India. First noted flight since it returned from a couple days at Al Udeid on Dec 2nd. pic.twitter.com/rO6tKtCSqx
— MeNMyRC (@MeNMyRC1) December 11, 2024
However, plenty of images of the WC-135R operating from an “undisclosed location” in the U.S. CENTCOM area of operations, confirm the deployment. Interestingly, the aircraft was monitored on its way back home on Dec. 16, as it flew back from Diego Garcia to its homebase at Offutt Air Force Base, Nebraska, via Andersen AFB, Guam.
Constant Phoenix 64-14831 outbound from Guam as Atom-31 and headed for Offutt. ~831 wrapped up its deployment to Diego Garcia yesterday stopping at Guam for Fuel early this morning. We should expect a stop for fuel and crew rest at Hawaii. pic.twitter.com/T4f0bHRchk
— MeNMyRC (@MeNMyRC1) December 16, 2024
The WC-135R is the only aircraft in the U.S. Air Force inventory capable of conducting air sampling operations. Operated and maintained by the 55th Wing’s 45th Reconnaissance Squadron, in collaboration with Air Force Technical Applications Center (AFTAC)’s 21st Surveillance Squadron, Detachment 1, the WC fleet specializes in atmospheric collection missions. Among its roles, the Constant Phoenix is equipped to sample gaseous debris in the atmosphere to detect radioactivity, supporting the Limited Nuclear Test Ban Treaty of 1963. This treaty prohibits above-ground nuclear weapons testing. Because of this unique mission, the WC-135 has earned the nickname “Nuke Sniffer.”
The WC-135 fleet plays a vital role in national security, conducting global atmospheric sampling missions: the aircraft is equipped with external devices that help collect airborne particles on filter paper and use a compressor system to gather whole air samples. The system works like an old Wurlitzer jukebox, where an arm grabs the filter paper from a slot and moves it outside the aircraft to collect samples. After exposure, the paper is returned to the magazine, and a new one is selected.
Effluent gasses are gathered by scoops on the sides of the fuselage, which trap fallout particles on filters. The mission crews have the ability to analyze the fallout residue in real-time, helping to confirm the presence of nuclear fallout and possibly determine the characteristics of the warhead involved.
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The addition of a third aircraft allows the 45th Reconnaissance Squadron to better respond to urgent calls from combatant commanders while maintaining a rigorous training schedule.
The Constant Phoenix fleet is currently made of three upgraded WC-135R aircraft: 64-14836, 64-14831 and 64-14829.
The “new” WC-135Rs are actually converted KC-135R refueling planes. Their switch from Stratotankers to nuclear sniffers started back in 2019 at the 645th Aeronautical Systems Group, a maintenance depot known as “Big Safari.” The first aircraft, tail 4836, arrived in July 2022, with the second one, tail 4831, following in May 2023. The third and final one, tail 4829, delivered to the Air Force in 1964 and flying with the Arizona Air National Guard before getting its upgrade, was delivered on Dec. 4, 2023.
These jets replaced the two WC-135C/W airframes (out of a total of 10 originally in service) which were retired in November 2020 and September 2022. Compared to their predecessors, the upgraded WC-135R aircraft come with a new cockpit and CFM-56 turbofan engines, which also address issues the older WC-135W fleet had, where outdated engines were prone to failure, creating safety concerns.
“Having three aircraft in the fleet changes the game,” said Col. Mark Howard, 55th Wing commander when the final R model was delivered last year. “We can handle simultaneous missions without compromising training or operational readiness.”
To carry out their critically important atmospheric sampling mission, the three WC-135Rs are regularly deployed worldwide. Their presence at bases outside the Continental U.S. (CONUS) is often revealed by aircraft spotters who capture photos of the “Nuke Sniffers” taking off or landing, or through OSINT (Open Sources Intelligence), using flight tracking websites or monitoring the aircraft’s radio communications. In fact, the U.S. Air Force rarely acknowledges the deployment of the Constant Phoenix.
One notable exception (before today’s photos about the deployment to the Persian Gulf area), occurred in 2017, when the WC-135W 62-3582 completed a “tour” in Europe, arriving on Feb. 17, 2017 and conducting several missions both in the Barents Sea area and in the Mediterranean Sea until mid March. The pretty rare deployment to RAF Mildenhall, UK, amid raising concern for an alleged spike in Iodine levels around Norway, fueled speculations that the U.S. had sent the detection aircraft to investigate the reasons behind the radioactive levels detected in northern Europe at the beginning of January. The U.S. Air Force denied the aircraft was deployed for that purpose instead stating it just conducting a “pre-planned rotational deployment scheduled in advance,” as Air Force spokeswoman Erika Yepsen explained.
