Japan ordered a halt to all flights of Boeing Co. 777s equipped with the type of engine that failed Saturday over Denver as U.S. aviation regulators ordered emergency inspections of the model’s fan blades.
Japan’s transport ministry on Sunday ordered ANA Holdings Inc. and Japan Airlines Co. to ground Boeing 777 planes they operate following an engine failure that rained debris over a Denver suburb but injured no one.
The airlines had already taken the planes out of service — 13 operated by JAL and 19 by ANA — before the Ministry of Land, Infrastructure, Transport and Tourism issued the order.
A PW4000 engine made by Raytheon Technologies Corp.’s Pratt & Whitney division powering a Boeing 777-200 bound for Honolulu failed on takeoff Saturday, scattering debris over a residential area near Denver. The plane was able to return to Denver airport and land safely.
The grounding of the 32 planes caused a cancellation of one JAL flight from Okinawa Prefecture's Naha to Tokyo's Haneda on Sunday. JAL and ANA said they are substituting other aircraft and there will be no flight cancellations from Monday onward.
On Dec. 4, an engine on a JAL plane operating a Naha to Haneda service experienced trouble, forcing the aircraft to make an emergency landing. It was the same Pratt & Whitney engine and the ministry had since instructed JAL and ANA to inspect aircraft using the engine more frequently than usual.
The ministry said it is investigating whether additional measures are required to ensure the safety of the engines.
JAL and the ministry concluded that the incident in December was caused by fan blade damage.
United Airlines is the only U.S. operator of the planes, according to the U.S. Federal Aviation Administration. The other airlines using them are in Japan and South Korea, the agency said.
An official at South Korea's transport ministry said it was waiting for formal action by the FAA before giving a directive to its airlines. The U.S. agency said it would soon issue an emergency airworthiness directive.
Korean Air Lines Co., which has 16 of the planes, 10 of them stored, said on Monday it grounded the remaining six it had in operation of its own volition.
Asiana Airlines Inc., which has nine 777s with Pratt & Whitney engines, said it is in discussion with Boeing and the relevant authorities on what measure to take.
The FAA ordered inspections after examining the hollow fan blade that failed, the agency said in an emailed statement Sunday evening. The inspections apply to Boeing 777s equipped with PW4000 engines.
FAA Administrator Steven Dickson said the aggressive inspections "will likely mean that some airplanes will be removed from service.”
The scare comes at an extremely sensitive time for the global aviation industry, which has been plunged into crisis by the coronavirus pandemic and its impact on travel. Boeing is only just dusting itself off from the nearly two-year grounding of its best-selling 737 Max following fatal crashes in Ethiopia and Indonesia, while Pratt has faced separate issues with its geared turbofan engines on Airbus SE A320neo jets, particularly in India.
United Airlines said it will voluntarily halt operations of 24 of its planes while the Federal Aviation Administration order is carried out.
"After consulting with my team of aviation safety experts about yesterday’s engine failure aboard a Boeing 777 airplane in Denver, 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,” Dickson said in an emailed statement.
While the incident doesn’t suggest broader problems with the 777, it adds another urgent issue to Boeing’s to-do list only just after the 737 Max was cleared to fly again in markets including the U.S. and Europe. The company has halted deliveries of its 787 Dreamliners to check for manufacturing flaws.
"We recommended suspending operations of the 69 in-service and 59 in-storage 777s powered by Pratt & Whitney 4000-112 engines until the FAA identifies the appropriate inspection protocol,” Boeing said in a statement, adding that it supports decisions by the FAA and Japan’s Civil Aviation Bureau to temporarily ground aircraft powered by the engines.
Only 60 Pratt-powered 777-200 and -300 models are still flying globally, according to analysis of Cirium data by George Ferguson at Bloomberg Intelligence. Another 67 of the jets are sitting in storage, although they haven’t officially been retired.
The latest inspections could hasten the end of the earliest 777 models if the repairs turn out to be costly, Ferguson said. "They are already out of favor because of their size and the pandemic.”
The 777 is distinctive for its hulking turbofans that are about as wide as a 737 jetliner cabin. The PW4000-112 debuted with the first of the 777s to fly in 1995, and was also available to customers of the later -200ER and -300 models. In 1999, Boeing awarded General Electric Co. an exclusive contract to power newer, longer-ranger versions of the 777 with its GE90 engines and eventually phased out the Pratt offering.
"Pratt has not had any market share in this space for a long time,” Ferguson said. "It’s all GE.”
The crack that led the fan blade to break on the United flight was similar to one that occurred on a 2018 United flight, said a person familiar with the preliminary investigation results who wasn’t authorized to discuss them.
In the latest failure, one fan blade cracked and broke off near where it attached to a rotating hub, according to the person. A second blade was also broken, apparently after it was struck by the first blade.
The fan blades on this type of PW4000 are hollow and made of titanium. The cracks appear to start from within the surface, making them hard to detect. Airlines can use technologies such as ultrasound to find cracks beneath the surface. The blades are only used on some 777 planes, said the FAA, which is stepping up the frequency of inspections.
Representatives for Pratt had no immediate comment.
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