During the Cold War, the SR-71 performed reconnaissance missions over the Baltic Sea, known as the "Baltic Express." The Swedish Saab JA-37 Viggen managed to lock onto an SR-71, a rare feat due to the Blackbird's superior speed.
Swedish pilots flying the Saab J37 escorted an American Lockheed SR-71 "Blackbird" safely back to Germany after the speedy spy pilot developed engine trouble.