Incident Overview
On February 20, 2021, United Airlines Flight 328, a scheduled domestic flight from Denver International Airport (DEN) to Honolulu, experienced a contained engine failure shortly after takeoff. The aircraft involved was a Boeing 777 powered by Pratt & Whitney (P&W) model PW4077 turbofan engines.
Engine Failure and Damage
The engine failure was caused by a fan blade separation due to metal fatigue. This event led to an engine fire and extensive damage to the nacelle. Although the failure was classified as contained—meaning the fan blade fragments remained inside the nacelle—large parts of the engine's cowling, inlet, and thrust reverser detached from the aircraft. These dislodged components fell over a debris field spanning more than 1 mile (1.6 km) across residential areas of Broomfield, Colorado.
Aftermath
The aircraft subsequently returned to Denver International Airport. No further details about the flight's occupants or ground impact were provided in the source.