Boeing 777s with the same engine as Denver plane which caught fire banned from UK airspace

An engine on Flight 328

Credit: Chad Schnell

The fire erupted shortly after take-off on United Airlines Flight 328 from Denver to Honolulu, on Saturday.

A total of 231 passengers and 10 crew were on board, and the flight returned safely to Denver airport after shedding debris across a residential area.

The US National Transportation and Safety Board (NTSB) said a preliminary investigation indicated two fan blades fractured on one of the engines.

An initial review concluded that the "inspection interval should be stepped up for the hollow fan blades that are unique to this model of engine.’

It emerged a similar incident happened on a Boeing 777 with a Pratt & Whitney engine on Feb 13, 2018.

That flight, also headed for Honolulu, set out from San Francisco and suffered a fractured fan blade, which similarly caused the engine to lose its cowling.

As in the incident last week, terrified passengers took pictures of the failing engine through their windows. None of the 374 passengers and crew were injured.

Both planes in the two incidents were the exact same age, having made their first flights within weeks of each other in 1994.

Parts of the debris from the United Airlines flight 328 in Broomfield, Colorado

Credit: Broomfield Police Department/HANDOUT/EPA-EFE/Shutterstock 

A report into the 2018 incident by the NTSB was released last July, and concluded inspections had failed to spot signs that a blade was weak.

The report said Pratt & Whitney did not provide a formal programme for training its inspectors who examined the fan blades.

A blade had shown signs of metal wear and tear in 2010 and 2015, but inspectors believed it was just a paint imperfection.

After that report came out seven months ago Pratt & Whitney said they had taken corrective actions.

Additionally, in response to the 2018 incident the FAA, a year later, ordered inspections of fan blades on all PW4000 engines.

On the same day as the Denver incident a Boeing 747-400 cargo plane dropped engine parts after a mid-air explosion and fire over the the Netherlands.

It was powered by a smaller version of the engine on the Denver plane.

The Denver incident was the latest setback for Boeing, which only recently resumed deliveries of the long-grounded 737 MAX following two fatal crashes of that plane.

Meanwhile, it emerged air freight costs could be driven up if problems with the type of engine were found to be widespread.

The Pratt & Whitney 4000 family of engines is widely used across cargo aircraft. Air cargo prices have already risen by more than 25 per cent since the start of the pandemic