Washington, March 10 (BNA) The US Federal Aviation Administration (FAA) said on Wednesday that it is finalizing three safety directives for some Boeing 777 aircraft that have been grounded with Pratt & Whitney 4000 engines that will allow them to return to service.
The new final airworthiness guidance covers Boeing 777 aircraft such as the United Airlines 777 that failed shortly after take-off from Denver in February 2021, sending debris falling over nearby cities. No one was injured, and the plane returned safely to the airport, Reuters reported.
The Federal Aviation Administration said the new guidance, which was proposed in December after three propeller malfunctions reported in-flight, requires improved inspections and modifications that will allow Boeing 777-200 and -300 aircraft equipped with Pratt & Whitney engines to resume flights after they were completed. Grounded for over a year.
One directive requires the installation of debris guards on the inner wall to reverse thrust, inspection of fan cover doors for moisture ingress and frequent checks of hydraulic pump shut-off valves. The other requires modification of the motor inlet to withstand the events of fan blade failure. The third requires specific corrective actions based on the results of the examination.
The directives will go into effect in mid-April.
In February 2021, the agency ordered immediate inspections of 777 aircraft with PW 4000 engines before more flights, after the National Transportation Safety Board found a cracked propeller blade in the United engine.
United, which is the only US operator of the 777 with the PW4000 engine and has 52 of these aircraft, said the move “is a good and safe outcome for our industry and our united customers.”
The airline said that “several of the affected engines have already undergone these proposed modifications. We expect these aircraft to resume flying customers again soon.”
Boeing must now develop a service bulletin outlining the steps airlines must take to meet the requirements. This notice must be approved by the FAA before the aircraft can return to service.
Boeing did not immediately comment.
In April, Japan Airlines said it had withdrawn its fleet of 13 Boeing 777 aircraft with PW4000 engines a year earlier than planned, after suspending operations in February.
The Japanese carrier had an accident of its own with its PW4000 engines in December, when a malfunction forced a JAL 777 bound for Tokyo to return to Okinawa’s Naha Airport.
The engines power only a small number of older 777 aircraft operated by JAL, United, ANA Holdings, Korean Air Lines, Asiana Airlines and Jin Air.