(CNN Business) – United Airlines recalled all of its Boeing 777s currently in service, powered by Pratt & Whitney 4000 engines, after the Federal Aviation Administration (FAA) ordered more intensive inspections.
The airline announced on Sunday that it would immediately recall the planes “as a precaution.” The 24 aircraft are part of the 52 Boeing 777s in United’s fleet. The remaining 28 remain stored.
The measure is voluntary and temporary, United said, and should only affect “a small number of customers.”
The announcement came after the FAA issued an emergency order saying it would intensify inspections of Boeing 777s equipped with certain Pratt & Whitney PW4000 engines.
“We reviewed all available safety data after yesterday’s incident,” said FAA Administrator Steve Dickson. He was referring to the United Airlines flight that was forced to return to Denver International Airport on Saturday after suffering an engine failure shortly after takeoff, causing debris in Denver.
What went wrong on the United Airlines flight?
“Based on the initial information, we concluded that the inspection interval should be increased for hollow blades unique to this engine model, which is only used in Boeing 777 aircraft,” said Dickson.
The National Transportation Safety Board (NTSB) said on Sunday that an initial investigation of the Pratt & Whitney PW4077 engine on United Airlines Flight 328 showed that two blades had broken and the remaining blades were damaged “in the blades.” Points and edges “.
These are preliminary findings and should not be considered conclusive as to what went wrong on Saturday, but they are still significant.
Investigators believe a blade on the Boeing 777’s engine that experienced a catastrophic failure on Saturday broke free and took another blade, a source familiar with the situation told CNN.
On Sunday evening, Boeing advised suspending all of its 777s with Pratt & Whitney 4000 engines.
“While the NTSB investigation is underway, we recommend that operations of 69 777s in service and 59 in storage, powered by Pratt & Whitney 4000-112 engines, be suspended until the FAA finds the correct inspection protocol “said Boeing’s statement.
Countries that use the Boeing 777
According to the most recent registration data, the only airlines using the affected engines are in the United States, Japan and South Korea. United is the only American operator with this type of engine in its fleet.
Japan’s Ministry of Transport said it has ordered domestic airlines to cease operations of Boeing 777 jets equipped with Pratt & Whitney PW4000 engines.
“Boeing supports yesterday’s decision by the Japanese Civil Aviation Bureau and today’s action by the FAA to suspend operations of 777 aircraft with Pratt & Whitney 4000-112 engines. We are working with these regulators to take action while these planes are on the ground and Pratt & Whitney is conducting further inspections, ”the company said in its statement on Sunday.
The NTSB said the “investigator responsible for this event along with a power plant specialist” traveled from Washington to Denver on Sunday morning to assist local NTSB investigators.
The agency said it will investigate “the engine, the aircraft, and the photos and videos taken by the passengers on board United Flight 328.” The NTSB will also assess flight data and cockpit voice recorders.