London, United Kingdom: United Airlines Flight UA939, a Boeing 777-200ER operating from London Heathrow to San Francisco, was forced to return to its departure airport on Sunday evening due to a technical issue with its right-hand engine. The flight, scheduled to last roughly ten hours, declared an emergency shortly after takeoff to ensure passenger safety.
The aircraft departed London Heathrow at 16:21 BST but less than an hour into its journey the crew identified a mechanical problem. Following standard safety protocols, the pilots decided to hold the aircraft at 31,000 feet while preparing for a safe return to London.
Fuel was dumped to make landing safer to reduce landing weight, a routine procedure in such emergencies. By 17:50 BST, the aircraft had completed the fuel-dumping process and began its descent back to Heathrow. No injuries have been reported. The flight UA939 was delayed by approximately 2 hours and 53 minutes.
Earlier this year, on July 25, 2025, United Airlines Flight 108, a Boeing 787-8 Dreamliner, experienced a left engine failure shortly after departing Washington Dulles International Airport en route to Munich. At approximately 5,000 feet, the crew declared a Mayday emergency and initiated a return to the airport.
Due to the aircraft’s heavy fuel load for the transatlantic flight, the pilots entered a holding pattern to burn fuel and reduce weight before landing safely back at Dulles after about 30 minutes in the air. All passengers and crew members disembarked without incident.
