Watch: U.S. inspects Boeing planes after engine fail
The latest blow for Boeing's (BA) aircraft business came this weekend after one of its 777 planes, bound for Hawaii, caught fire and showered debris across a suburb of Denver in the US. Nobody was injured.
United Airlines flight 328 to Honolulu landed safely back in Denver after parts of the plane appeared to fall away after take-off.
The incident led to both the US and Japan grounding fleets of the aircraft, as the US airline safety regulator stepped in to investigate. The UK has also temporarily banned the plane from entering UK air space.
The Federal Aviation Administration (FAA) issued an emergency airworthiness directive, calling for an inspection of the 777. There had been two separate incidents involving engine faults over the weekend.
The plane's engine, a Pratt & Whitney PW4000, is solely used on Boeing 777s. Boeing said it would suspend use of planes while the FAA looks into safety concerns. There are 69 of these planes currently in service and a further 59 in storage.
The regulator said in a statement: "We reviewed all available safety data. 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."
On the Hawaii-bound flight two fan blades in the engine were fractured, while others "exhibited damage."
A statement from the National Transportation Safety Board (NTSB) said it was too early to draw conclusions about how the incident happened.
According to Nikkei Asia, Japan has decided to stop operating a total 32 planes with the engine in question, with the country's ministry of land, infrastructure, transport and tourism ordering the planes to be taken out of service.
— michaela🦋 (@michaelagiulia) February 20, 2021
Boeing 737 MAX issues
The grounding presents a fresh challenge to the credibility of the carrier, following issues with Boeing's 737 MAX over the last two years.
The aircraft was grounded worldwide for 20 months following two fatal crashes in Indonesia and Ethiopia that killed 346 people.
US safety regulators cleared the plane to fly again in North America and Brazil in November last year.
The company’s former senior manager Ed Pierson recently said at the time he felt that the vehicle was cleared to fly too early.
The Federal Aviation Administration (FAA) said existing planes would need to be modified before going back into service, with changes to their design, while pilots would need retraining.
It said the design changes it had required had "eliminated what caused these particular accidents.”
The plane also got the green light in Europe after the head of Europe's aviation safety agency, EASA, confirmed it will got final clearance to resume flying.
However Pierson, who retired from Boeing in August 2018, claimed in a report that investigators have overlooked factors he believes may have played a direct role in the incidents.
Investigators believe the accidents were triggered by the failure of a single sensor, specifically the MCAS software, as well as the regulatory oversight failures of the FAA, and the lack of training provided to pilots.
Watch: Boeing 777's engine falls apart over Colorado neighbourhood