Boeing confirmed Monday that dozens of its 777 aircraft were grounded globally after the engine of a United Airlines plane caught fire and scattered debris over a suburb of Denver, Colorado. 

It is a fresh blow for the beleaguered US aviation giant that was forced to ground another fleet of planes after a series of deadly crashes.

Boeing said Monday that 128 of its 777 planes with Pratt & Whitney engines will stop flying after the fire Saturday that forced the United Airlines plane to make an emergency landing. 

"I have just had confirmation that all the 777s equipped with this engine have been grounded," a spokeswoman for the planemaker told AFP in a text message. 

Flight UA328 had been headed from Denver to Honolulu when it experienced engine failure shortly after departure. 

A video shot from inside the plane -- which had 231 passengers and 10 crew on board -- showed the right engine ablaze and wobbling on the wing of the Boeing 777-200.

An engine on flight UA328 caught fire mid-flight.

Residents in the Denver suburb of Broomfield found large pieces of the plane scattered around their community.

Its front cowling, which landed in the front yard of a house, was entirely missing as the aircraft returned to Denver airport.

There were no injuries on the plane or on the ground, authorities said.

Stepped-up inspections 

The US Federal Aviation Administration had ordered extra inspections of some passenger jets after the incident.  

Steve Dickson, the head of the regulator, said he had consulted with experts, signalling the planes would likely be removed from the air. 

"I have directed them to issue an Emergency Airworthiness Directive that would require immediate or stepped-up inspections of Boeing 777 airplanes equipped with certain Pratt & Whitney PW4000 engines," he said in a statement.

Dickson added that a preliminary safety data review pointed to a need for additional checks of the jet engine's fan blades, which were unique to the engine model and only used on 777 planes. 

Officials from the FAA met with Pratt & Whitney and Boeing representatives on Sunday evening, he added.

The US National Transportation and Safety Board also said it is investigating the incident, while United Airlines, Asiana, Japan Airlines and All Nippon Airways grounded their planes earlier.   

Japan's transport ministry had earlier said it had ordered stricter inspections of the engine after a Japan Airlines 777 plane flying from Haneda to Naha experienced trouble with "an engine in the same family" in December.

Asiana Airlines, South Korea's second-largest carrier, had also said it would not fly any of its seven currently operational 777s. 

Fresh blow for Boeing 

The engine failure is unwelcome news for Boeing following several high-profile accidents.

The manufacturer's 737 MAX was grounded worldwide in March 2019 after 346 people died in two crashes -- the 2019 Lion Air disaster in Indonesia and an Ethiopian Airlines crash the following year.

Investigators said a main cause of both crashes was a faulty flight handling system known as the Maneuvering Characteristics Augmentation System, or MCAS.

Boeing was forced to revamp the system and implement new pilot training protocols.

This month the aircraft made its first commercial flight in Europe since the grounding, after the continent's air safety regulator EASA approved the return of the 737 MAX.

The FAA and Britain's Civil Aviation Authority have also cleared the aircraft for flying again. 

The 737 MAX was a big hit with airlines, becoming Boeing's fastest-selling aircraft until its grounding, which has now been lifted. 

After the Covid-19 crisis decimated demand, airlines cancelled hundreds of orders for the plane.