The FAA has set a firm deadline of March 2033 for Pratt & Whitney-powered Boeing 777 operators to fully comply with engine nacelle upgrade requirements designed to minimize risk following an engine fan blade failure—a five-year extension of the previous deadline.
The agency's decision, issued June 16, denied a Boeing request to push airworthiness limitations compliance—or maintenance instruction updates—out to March 2038. It also proactively gave Boeing another two years, or until March 4, 2029, to submit all design changes to the FAA.
A 2022 exemption gave Boeing until March 2027 to finalize the proposed changes, and operators an additional year to incorporate them. Pratt also developed modifications as part of the changes prompted by three in-service engine failures, in 2018, 2020 and 2021. The effort's complexity prompted Boeing to petition the FAA in May 2025 for more time than the 2022 exemption provides.
Boeing's recent petition included an update on its progress, which the FAA treated as proprietary. The agency, citing the project's "complexity," determined Boeing needed more time to complete its share of the work.
"The FAA’s review of your proprietary data submitted in support of this petition, in addition to the regular project schedule provided ... indicates that it is unlikely Boeing will submit for FAA approval all design changes needed to show full compliance by the current deadline of March 4, 2027," the agency wrote in its June 16 decision. "Therefore, the FAA has determined that it is in the public interest to extend the due date ... by two years, from March 4, 2027, to March 4, 2029."
The Pratt-powered 777 fleet was grounded in February 2021 following the third in-service incident. Pratt, Boeing and the FAA developed a return-to-service plan that included immediate inlet and thrust reverser modifications and an inspection program. Additional changes, including fan cowl and engine flange modifications being incorporated as part of the package, are subject to the 2033 deadline.
The new timeline compresses an already tight window between Boeing's deadline for finalizing the design changes and when operators must have them in place. But the real-world impact may be minimal.
United Airlines operates the most Pratt-powered 777s, but the fleet is shrinking. Aviation Week Fleet Discovery shows 40 in service and two parked. When the grounding took place in 2021, United had 52 PW4000-powered 777-200s.
The global fleet size, which numbered about 120 five years ago, is also getting smaller. Fleet Discovery shows 71 in service, including six that are parked. Another 25 show as in storage but not formally retired.
Related Content
