The 1968 Thule Air Base B-52 crash, Thule affair or Thule accident was an accident on January 21, 1968, involving a United States Air Force (USAF) B-52 bomber. The aircraft was carrying four hydrogen bombs on a Cold War "Chrome Dome" alert mission over Baffin Bay when a cabin fire forced the crew to abandon the aircraft before they could carry out an emergency landing at Thule Air Base.