Pratt & Whitney has reduced life limits on PW1500G and PW1900G geared turbofan (GTF) high-pressure compressor (HPC) front hubs after excessive corrosion was discovered during a routine overhaul, and the FAA plans to mandate the change.

The US agency, in a notice of proposed rulemaking (NPRM) published May 31, said Pratt discovered corrosion on a front hub “during a routine engine overhaul.” It was found beneath anti-corrosion coating. The issue “reduces the low-cycle fatigue capability and can occur even during engine downtime,” the agency added.

Pratt informed operators of the issue and its decision to reduce the hub life-limits in several service bulletins issued in April and May. The NPRM refers to the bulletins for details on the new life limits.

Pratt did not immediately respond to a request for comment.

The PW1500G and PW1900G engines power the Airbus A220 and Embraer E190/E195-E2 families, respectively. FAA said the directive affects 18 engines installed on US-registered aircraft.

Atlanta-based Delta Air Lines is the only US operator of either aircraft type—it operates A220s.

The life-limit reduction is likely to be adopted by other regulators around the world.

Sean Broderick, sean.broderick@aviationweek.com