Boeing said it recommended suspending the use of 777 jets with the same type of engine that shed debris over Denver at the weekend after U.S. regulators announced extra inspections and Japan suspended their use while considering further action.
"Boeing is actively monitoring recent events related to United Airlines Flight 328. While the NTSB investigation is ongoing, 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 supports the decision by the Japan Civil Aviation Bureau, and the FAA’s action to suspend operations of 777 aircraft powered by Pratt & Whitney 4000-112 engines. We are working with these regulators as they take actions while these planes are on the ground and further inspections are conducted by Pratt & Whitney," Boing said
Shortly after the National Transportation Safety Board was notified of the event, a senior NTSB investigator who lives in the Denver area began working with local law enforcement officials to coordinate the recovery of the components that separated from the engine, many of which landed in residential areas. Three other investigators from the NTSB's Denver regional office are assisting.
The NTSB investigator-in-charge for this event along with a powerplant specialist traveled from Washington to Denver Sunday morning.
The initial examination of the airplane indicated most of the damage was confined to the number 2 engine; the airplane sustained minor damage. The examination and documentation of the airplane is ongoing.
The initial examination of the Pratt & Whitney PW4077 engine revealed:
• The inlet and cowling separated from the engine
• Two fan blades were fractured
• One fan blade was fractured near the root
• An adjacent fan blade was fractured about mid-span
• A portion of one blade was imbedded in the containment ring
The remainder of the fan blades exhibited damage to the tips and leading edges
Investigators continue to examine the engine, airplane and the photographs and video taken by passengers aboard United flight 328.
The cockpit voice recorder and flight data recorder were transported to the NTSB laboratory in Washington where each will be downloaded and analyzed.
The following initial investigative groups have been established by the investigator-in-charge: structures, powerplants, operations factors, maintenance records,
flight data recorder and cockpit voice recorder.
Parties to the investigation include the Federal Aviation Administration, United Airlines, Boeing, Pratt & Whitney, the Air Line Pilots Association, and the Independent Brotherhood of Teamsters.
Analysis of this event, along with conclusions and a determination of probable cause, will come at a later date when the final report on the investigation is completed. ■