Airlines in Japan and the US have grounded dozens of Boeing 777 aircraft after the dramatic engine failure that United Airlines flight 328 experienced over Denver this weekend. The National Transportation Safety Board’s ongoing investigation found two fan blades on the plane’s number 2 engine had developed fractures.

The federal Aviation Administration issued an emergency airworthiness directive that requires’immediate or stepped-up inspections of Boeing 777 airplanes equipped with certain Pratt & Whitney pw4000 engines’. The administration noted that this was likely to result in aircraft being removed from service.

Boeing has told airlines to stop flying planes equipped with the engine. Boeing has also told airlines not to stop aircraft equipped with engine.

Flight 328 @ United engine caught fire. My parents are on this flight and everyone’s okay. Flight 328 was the first engine to catch fire.

‘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’s civil aviation bureau ordered Japan Airlines and all Nippon Airways to remove their aircraft with the same engines from service. Jal operates 14 and Ana has 19, according to reports.

United flight 328 was bound for Honolulu but safely returned to Denver after experiencing the engine failure shortly after takeoff. No-One was injured on the flight’s return to Denver.