A U.S. reconnaissance aircraft specializing in signals intelligence collection has arrived in Europe, part of an annual transatlantic mission to assess enemy radars, Paralel.Az reports citing Newsweek.

Data captured on August 20 by the aircraft tracking service Flightradar24 showed the U.S. Air Force's RC-135U, known as the Combat Sent, had already conducted an hourslong flight in the Baltic region bordering Russia and neighboring Belarus.

The Combat Sent—one of only two in the Air Force's inventory—landed at the U.K.'s Mildenhall air base in eastern England on Sunday, having departed its home at Nebraska's Offutt Air Force Base and stopped in Delaware on its way across the Atlantic Ocean, according to the GPS data.