Is US preparing for Iran? Rare ‘nuke sniffer’ plane lands in Britain as Trump weighs action on Tehran

A US air force plane WC-135R Constant Phoenix has landed in Britain amid growing tensions with the Iranian regime. The Constant Phoenix is a specialised United States Air Force aircraft designed to detect radioactive particles in the atmosphere and monitor nuclear activity. It is sometimes called the 'nuke sniffer' because its onboard systems collect particulate and gaseous debris that could indicate nuclear tests or fallout, supporting the Limited Nuclear Test Ban Treaty of 1963, which bans above-ground nuclear tests.

The aircraft was observed at an undisclosed airbase in the UK on Thursday where US special forces were also seen carrying out 'fast roping' training drills from a V-22 Osprey aircraft, this technique is used to deploy troops behind military lines, according to the Daily Mail report. Such deployments are uncommon, as this is only the third time in 40 years that it has been sent to a UK airbase.

The Constant Phoenix’s primary role is atmospheric sampling, gathering air samples to detect signs of nuclear explosions and incidents or radiation leaks. By analysing collected particles, the aircraft contributes to verification of international treaties that prohibit certain types of nuclear testing. The nuke sniffer is operated by the 45th Reconnaissance Squadron.

The aircraft’s arrival came as the United States increased its military presence in the region, including the deployment of the USS Abraham Lincoln and other assets near the Middle East amid rising tensions involving Iran. Reports note that such deployment patterns have, in the past, preceded periods of heightened military alert or conflict, though there has been no official confirmation linking the current movement to any specific operation. Notably, the last time the US Air Force’s WC-135 deployed from the United States to the Middle East was weeks before Israel and the US carried out a joint attack on Iran’s nuclear facilities during the 12-day war in June 2025.

The Constant Phoenix has carried out numerous missions over various regions to collect data on atmospheric radiation, including prior overflights of oceans, polar regions, and the Mediterranean. It was deployed in 1986 after the Chernobyl disaster, in 2011 after the Fukushima Nuclear Power Plant incident, during North Korean nuclear tests and at the start of the Ukraine Russian war in 2022.

The WC-135 has a range of about 4,000 nautical miles and can carry up to 1,30,000 pounds of fuel, allowing it to conduct long-duration surveillance missions. Its air-sampling role directly supports the Limited Nuclear Test Ban Treaty of 1963, which prohibits nuclear weapons testing above ground. Notably, the WC-135 fleet remains the only aircraft in the US Air Force inventory dedicated exclusively to atmospheric radioactive sampling. The Air Force’s transitioned from the legacy WC-135W fleet to the new WC-135R fleet of three aircraft by December 2023.

Official statements from US or UK authorities explaining the purpose of the WC-135R’s deployment to Britain have not been released. Defence sources quoted by media emphasised that the presence of the aircraft does not necessarily indicate immediate military action.