Delta Flight 014 from Atlanta to Frankfurt turned back shortly after takeoff Friday night because of a mechanical issue with one of the plane’s engines, the airline said in a statement. “The aircraft landed safely and was met by firetrucks, which sprayed down the aircraft’s brakes due to the heavier than normal landing weight,” Delta said.

Passengers on board a Delta flight on Monday were forced to evacuate via emergency slides after smoke or haze consumed the plane's inside, according to the U.S. Federal Aviation Administration and airline officials.