A United Airlines flight traveling from Washington Dulles International Airport made an emergency landing last month after the pilot declared a mayday call shortly after takeoff due to engine failure.

The Boeing 787, flying from the Washington, D.C., area to Munich, had to make a hasty return to the airport "to address a mechanical issue," United said.

A newly-released audio recording has revealed the dramatic moment that a United Airlines flight with over 200 people on board suffered engine failure.