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

A United Airlines pilot declared mayday late last month, suspecting possible engine failure after takeoff from Dulles International Airport near Washington, D.C. “Engine failure, left engine, United 108 declaring an emergency.

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.