After the engine failure that United Airlines flight 328 experienced over Denver in the weekend airlines in Japan and the US have grounded dozens of Boeing 777 aircraft. Info from the ongoing investigation say two fan blades on the plane’s number 2 engine had developed fractures in the incident. Investigators noted that the inlet, a duct which is required to ensure smooth airflow into the engine, and a cowling, the removable metal covering that houses the engine, were separated from the engine. In addition, two fan blades were fractured while the remainder of the blades exhibited damage to their tips and leading edges. Blades are unique to this model of engine, used solely on Boeing 777 airplanes.
The Federal Aviation Administration issued an emergency airworthiness directive that requires “immediate or stepped-up inspections of Boeing 777 airplanes equipped with certain Pratt & Whitney PW4000 engines.” Boeing has also told airlines to stop flying planes equipped with the engine. No-one was injured on United flight 328, which was bound for Honolulu but safely returned to Denver. According to the most recent registry data, airlines in only three countries operate airplanes with the affected engines: the United States, Japan, and South Korea. In addition to its 24 active aircrafts, United has 28 additional Boeing 777s in storage.