The Federal Aviation Regulator ordered United Airlines to strengthen inspections of all Boeing 777s equipped with the following engine typesOver Denver on Saturday. Manchester United said it will temporarily stop using these aircraft.
The announcement was the second day after United Airlines Flight 328 had to make an emergency landing at Denver International Airport after the right engine burst. Pratt & Whitney’s PW4000 engine casings are scattered in the suburbs.
Authorities said the plane carried 231 passengers and 10 crew members and landed safely. No one was on the plane or injured on the ground.
Federal Aviation Administration Commissioner Steve Dickson said in a statement on Sunday that based on a preliminary review of the safety data, inspectors “concluded that the uniqueness of this engine model should be increased. The inspection interval for hollow fan blades, which are only used on Boeing’s 777 aircraft.”
The National Transportation Safety Board said in a separate statement that two of the engine’s fan blades were broken and the remaining fan blades were “damaged.” The NTSB cautioned that it is too early to draw conclusions on how the incident occurred.
Boeing said it recommends that “69 in service and 59 in service Boeing 777 aircraft” worldwide be suspended with Pratt & Whitney engines until the FAA determines an appropriate inspection agreement.
Pratt & Whitney issued a statement saying that it “has sent a team to work with researchers” and “is actively coordinating with operators and regulators to support revised inspection intervals for the engines involved.”
A video posted on Twitter showed that the engine was completely engulfed in flames while the plane was flying in the air. Frames in different videos taken by passengers sitting slightly in front of the engine were frozen and posted on Twitter, showing that the fan blades in the engine were damaged.
The FAA stated that United Airlines is the only American airline in the fleet with Pratt & Whitney PW4000. Manchester United said that there are currently 24 of the 777 in service.
Manchester United said it will work closely with the Federal Aviation Administration (FAA) and NTSB to “determine any other steps to ensure that these aircraft meet our strict safety standards and can be put back into service.”
NTSB said the cockpit voice recorder and flight data recorder have been shipped to the Washington laboratory for data download and analysis. NTSB’s investigation may take as long as a year or even longer, although in major cases, the agency usually releases some investigation materials in the middle of the investigation process.
Airlines in Japan and South Korea also use Pratt & Whitney engines to run their aircraft. According to the “Nikkei Shimbun” report, Japan Airlines and All Nippon Airways have decided to stop using the engine to operate 32 aircraft at the same time.
Nikkei reported that the Japanese Ministry of Land, Infrastructure, Transport and Tourism also ordered the suspension of aircraft operations. The ministry stated that the same PW4000 family of engines suffered unspecified troubles on a JAL 777 from Naha to Haneda on December 4. In response, stricter inspections will be conducted.
Boeing stated that it “supports…the decision of the Civil Aviation Administration of Japan” and the “action of the FAA” to suspend operations of the Pratt & Whitney 777 aircraft.
Boeing added: “We are cooperating with these regulatory agencies because they will take action when these aircraft are on the ground and will be further inspected by Pratt & Whitney.”