A rare United States Air Force aircraft, designed to detect nuclear explosions, is patrolling the Baltic Sea today, close to the airspaces of Estonia, Latvia and Lithuania.
The Boeing WC-135 Constant Phoenix – known as the “nuclear sniffer” – departed RAF Mildenhall in the UK at 8:01 AM and has since been tracked flying racetrack patterns over the Baltic at an altitude of 17,500 feet. Operating under the callsign JAKE27, it is currently moving westwards at a speed of about 320 knots, according to flight data.
The Constant Phoenix is one of the most specialised reconnaissance aircraft in service. Operated by the 45th Reconnaissance Squadron at Offutt Air Force Base in Nebraska, it carries equipment capable of collecting and analysing airborne particulates and gases that would confirm a nuclear detonation. Its systems include whole-air collection tanks, particulate samplers and directional gamma radiation sensors that allow operators to trace radioactive plumes in real time.
First commissioned by president Dwight D. Eisenhower in 1947, the aircraft has been central to nuclear monitoring ever since, from tracking the fallout of Chernobyl in 1986 to monitoring North Korean weapons tests and radiation from Japan’s Fukushima accident in 2011. Only a handful of Constant Phoenix aircraft exist, with the ageing WC-135C/W models now being replaced by upgraded WC-135Rs, such as the aircraft over the Baltic today.
Its patrol comes amid the continuing war in Ukraine and Moscow’s nuclear threats. Russia has stationed tactical nuclear weapons in Belarus, held exercises around Kaliningrad and used nuclear rhetoric to unsettle its neighbours. For the Baltic states – small NATO members sharing borders with Russia – the flight is a reminder of both their vulnerability and the alliance’s vigilance.
While NATO’s battlegroups and air policing missions provide visible deterrence, the WC-135 highlights another layer of monitoring: detecting the invisible signs of nuclear activity. Its appearance in European skies is rare – and certain to be noted in Tallinn, Riga and Vilnius.
A US Air Force spokesperson has been contacted by Estonian World for comment.
