Regulators are ordering United Airlines to step up inspections of all Boeing 777s equipped with the type of engine that suffered a catastrophic failure over Denver on Saturday.
United said it is temporarily removing those aircraft from service, as meanwhile Boeing recommended grounding aircraft with that model engine until the Federal Aviation.
The announcements come a day after United Airlines Flight 328 had to make an emergency landing at Denver International Airport after its right engine blew apart just after takeoff.
Pieces of the casing of the engine, a Pratt & Whitney PW4000, rained down on suburban neighbourhoods.
The plane with 231 passengers and 10 crew onboard landed safely, and nobody aboard or on the ground was reported hurt, authorities said.