Boeing 777’s midair malfunction puts focus on engine cover

The midair breakdown of a jet engine that spewed a trail of metal over a Colorado town is putting regulatory focus on the design and strength of engine coverings.

Four minutes into the Honolulu-bound United Airlines flight from Denver on Saturday, pilots and passengers heard a loud bang, and the plane’s right engine began vibrating, according to the National Transportation Safety Board’s preliminary analysis of the cockpit’s voice recorder. Within 20 minutes, the plane had landed on the runway back at Denver International Airport, with no injuries to anyone on the ground or aboard the plane.

However, large pieces of debris plunged from the sky, landing in yards and a soccer field. Photos and videos taken by passengers show the airplane’s right engine, stripped of its front coverings, oscillating and in flames.