US NTSB cites inadequate inspections in 2021 United engine failure

The National Transportation Safety Board said Friday the February 2021 engine failure on a United Airlines Boeing 777 in Colorado was due to a crack in a fan blade and cited inadequate inspections as a contributing cause.

In February 2021, the Federal Aviation Administration ordered immediate inspections of 777 aircraft with Pratt & Whitney 4000 engines before further flights following the incident, which led to the planes' grounding for more than a year.

The NTSB cited "the inadequate inspection of the blades, which failed to identify low-level indications of cracking, and the insufficient frequency of the manufacturer’s inspection intervals." Pratt & Whitney is a unit of RTX.