The head of the Federal Aviation Administration said on Sunday that he was requiring “immediate or stepped-up inspections” of all Boeing 777 planes equipped with a particular Pratt & Whitney engine model one day after the jet suffered a dramatic engine failure over Colorado.
Also on Sunday, United Airlines, the only American carrier affected by the F.A.A. order, said it was temporarily grounding the 24 Boeing 777 planes currently in use in its fleet with the Pratt & Whitney engines.
The F.A.A. announcement came shortly after its counterpart in Japan ordered airlines there to stop flying the plane, affecting 32 jets operated by All Nippon Airways and Japan Airways. Both the Japanese and American orders apply only to Boeing 777s equipped with Pratt & Whitney PW4000 engines.
“We reviewed all available safety data following yesterday’s incident,” the F.A.A. administrator, Steve Dickson, 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.”
The episode in Colorado, involving United Airlines Flight 328 on Saturday, resulted in no reported injuries, but the plane shed debris across three neighborhoods before landing safely in Denver.
In a statement on Sunday, United said “safety remains our highest priority — for our employees and our customers.” It continued, “That’s why our pilots and flight attendants take part in extensive training to prepare and manage incidents like United Flight 328. And we remain proud of their professionalism and steadfast dedication to safety in our day-to-day operations and when emergencies like this occur.”
Mr. Dickson said the F.A.A. was working with its counterparts around the world and said that its safety experts were meeting “into the evening” with Pratt & Whitney and Boeing to complete details of the required inspections. Only airlines in the United States, Japan and South Korea operate Boeing 777s with the affected Pratt & Whitney PW4000 engine model, according to the agency.
A spokesman for Japan Airways said the airline had already stopped using the 13 Boeing 777’s in its fleet that are equipped with the engine before the aviation authority issued its directive. Only three scheduled flights were affected. The airline last year said it planned to remove all 13 planes from its fleet by early next year.