U.S. regulators announced extra inspections on Boeing 777 jets using the same type of engine that shed debris over Denver on Saturday, while Japan went further and suspended their use while it considers what action to take.
The regulatory moves involving Pratt & Whitney 4000 engines came after a United Airlines 777 landed safely at Denver International Airport on Saturday after its right engine failed.
United Airlines said on Sunday it would voluntarily and temporarily remove its 24 active planes of this type from its schedule.
Images posted by police in Broomfield, Colorado, showed significant plane debris on the ground, including an engine cowling scattered outside a home and what appeared to be other parts in a field.
Japan's transport ministry ordered Japan Airlines (JAL) and ANA Holdings to suspend the use of 777s with Pratt & Whitney 4000 engines while it considered whether to take additional measures.
The transport ministry said on December 4, 2020, that a JAL flight from Naha Airport to Tokyo International Airport returned to the airport because of a malfunction in the left engine about 100 kilometers north of Naha Airport.
That plane is the same age as the 26-year-old United Airlines plane involved in Saturday's incident.
United Airlines is the only U.S. operator using the planes, according to the Federal Aviation Administration (FAA). The other airlines using them are in Japan and South Korea, the U.S. agency said.
"We reviewed all available safety data following yesterday's incident," the FAA said in a statement. "Based on the initial information, we concluded that the inspection interval should be stepped up for the hollow fan blades that are unique to this model of engine, used solely on Boeing 777 airplanes."
Japan said ANA operated 19 of the type and JAL operated 13 of them.
Pratt & Whitney, owned by Raytheon Technologies Corp, was not available immediately for comment.
Boeing said its technical advisers are supporting the U.S. National Transportation Safety Board with its investigation.
