The American aerospace company Boeing has recommended suspending the use of 777 jets with the same type of engine that shed debris over Denver (in Colorado) recently due to engine failure.
Following the latest incident the US regulators have announced extra inspections while Japan suspended the flight’s use to considering further action.
The moves involving Pratt & Whitney PW4000 engines came after a flight of the major American airlines United Airlines 777 landed safely in Denver recently after its right engine failed.
United said it would voluntarily and temporarily remove its 24 active planes, hours before Boeing’s announcement. Boeing said 69 of the planes were in service and 59 were in storage, at a time when airlines have grounded planes due to a plunge in demand thanks to the COVID-19 pandemic.
The manufacturer recommended airlines suspend operations until US regulators identified the appropriate inspection protocol.
The National Transportation Safety Board (NTSB) said its initial examination of the plane indicated most of the damage was confined to the right engine, with only minor damage to the airplane. It said the inlet and casing separated from the engine and two fan blades were fractured, while the remainder of the fan blades exhibited damage.
Japan’s transport ministry ordered Japan Airlines to suspend the use of 777s with PW4000 engines while it considered whether to take additional measures. The ministry said that on December 4, 2020, a Japan Airlines flight from Naha Airport to Tokyo returned to Naha due to a malfunction in the left engine.
Japan Transport Safety Board said on December 28 that it had found two of the left engine’s fan blades were damaged, one from a fatigue fracture. The investigation is ongoing.
United is the only American operator of the planes, according to the Federal Aviation Administration (FAA). The other airlines using them are in Japan and South Korea, the US agency said.
“We reviewed all available safety data,” the FAA said in a statement. “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.” The US agency said it would soon issue an emergency airworthiness directive.
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. Korean Air Lines said it had 16 of the planes, 10 of them stored, and it would consult with the relevant authorities.