© Reuters. FILE PHOTO: A Japan Airlines Boeing 777 lands at San Francisco International Airport in San Francisco
By Jamie Freed and David Shepardson
(Reuters) – Boeing (NYSE 🙂 Co recommended halting use of 777 jets powered by the same type of engine that spilled debris over Denver over the weekend after U.S. regulators announced additional inspections and Japan suspended their use while considering further action were.
The Pratt & Whitney PW4000 engine movements came after a United Airlines 777 landed safely in Denver on Saturday local time after its right engine failed.
United said the next day it would voluntarily and temporarily remove its 24 active aircraft, hours before Boeing’s announcement.
Boeing said 69 of the planes were in service and 59 in storage at a time when airlines were discontinuing planes due to a decline in demand related to the COVID-19 pandemic.
The manufacturer recommended that airlines cease operations until U.S. regulators have determined the relevant inspection protocol.
The affected 777-200 and 777-300 are older and less fuel efficient than newer models, and most operators are exhibiting them from their fleets.
Images released by police in Broomfield, Colorado showed significant aircraft debris on the ground, including a hood of a 26-year-old aircraft that was scattered outside a house.
The National Transportation Safety Board (NTSB) said its initial investigation into the aircraft found that most of the damage was confined to the correct engine and the aircraft suffered only minor damage.
It was said that the inlet, separate from the motor and two fan blades, and the case were broken, while the rest of the fan blades were damaged.
Japan’s Ministry of Transportation ordered Japan Airlines Co Ltd (JAL) and ANA Holdings Inc to suspend the use of 777s powered by PW4000 engines while considering whether to take additional action.
The ministry said that on December 4, 2020, a JAL flight from Naha Airport to Tokyo was returning to Naha due to a left engine malfunction.
The Japan Transport Safety Board announced on December 28 that two of the left engine’s fan blades were damaged, one from a fatigue fracture. The investigation is still ongoing.
According to the Federal Aviation Administration (FAA), United is the only US operator of the aircraft. The other airlines that use them are in Japan and South Korea, the US agency said.
“We checked all available safety data,” the FAA said in a statement. “Based on the initial information, we came to the conclusion that the inspection interval for the hollow fan blades, which apply only to this engine model and are only used on Boeing 777 aircraft, should be extended.”
Japan said ANA operates 19 of these and JAL operates 13 of them, although airlines said their usage had been reduced during the pandemic. JAL said its fleet should be retired by March 2022.
Pratt & Whitney, owned by Raytheon Technologies (NYSE 🙂 Corp., said it is coordinating with operators and regulators to support a revised inspection interval for the engines.
A South Korean Department of Transportation official said it was awaiting formal action from the FAA before issuing a policy to its airlines. The US agency announced that it will soon issue an airworthiness directive for emergencies.
Korean Air Lines Co Ltd said it had 16 of the aircraft, 10 of which were in storage, and it would consult with the relevant authorities.
In February 2018, a 777 of the same age, operated by United and heading to Honolulu, suffered an engine failure when a hood fell off about 30 minutes before the aircraft safely landed. The NTSB determined that the incident was due to a fracture of the full-length fan blades.
Because of that incident in 2018, Pratt & Whitney reviewed the inspection records for all previously inspected PW4000 fan blades, according to the NTSB. The FAA issued a guideline in March 2019 that requires initial and recurring inspections of the fan blades of PW4000 motors.