The Federal Aviation Administration (FAA) issued an emergency airworthiness directive late on Tuesday evening grounding a small number of planes that use the same type of engine that blew apart shortly after takeoff during a United Airlines flight from Denver to Honolulu.
The order only applies to U.S. operators of aircraft that use certain Pratt & Whitney PW4000 engines. The engine model is used exclusively on a small number of Boeing 777 planes. In the U.S., only United Airlines uses the PW4000 engine resulting in the temporary grounding of 24 planes.
United had already voluntarily removed the aircraft from service while it awaited advice from accident investigators. Air safety regulators around the world are likely to demand the same checks as the FAA before allowing affected planes to operate in their jurisdictions.
Some countries, including the United Kingdom and Japan have temporarily banned Boeing B777s with Pratt & Whitney 4000-112 series engines from their airspace until safety inspections are concluded.
The FAA has ordered operators to carry out inspections of the large titanium fan blades located at the front of each engine using thermal acoustic imaging technology. Thermal imaging can detect cracks on the interior surfaces of the hollow fan blades, or in areas that cannot be seen during a visual inspection according to a press release from the FAA.
The existing inspection cycle for this type of engine was once every 6,500 flight cycles but this might be amended based on the results of the thermal imaging checks. South Korea has already determined that inspections for this type of engine should be reduced to every 1,000 flight cycles following the United incident.
United Airlines confirmed it would comply with the requirements of the order following Saturday’s engine failure that resulted in debris being scattered across the Denver area. None of the 231 passengers or 10 crew onboard the plane, or anyone on the ground was injured.
The airline fears cargo deliveries could be delayed following the mass grounding and is working to reinstate aircraft currently in storage to keep up with freight demand. United has been playing a role in the delivery of COVID-19 vaccines across the United States.
