FAA finalizes directive to address powder metals’ iron contamination on GE90s powering Boeing 777s

The Federal Aviation Administration (FAA) has finalized an airworthiness directive (AD) to address issues related to specific GE Aerospace GE90 engines’ high-pressure turbine (HPT) stage 1 and stage 2 disks, which were manufactured from powder metal suspected to contain iron inclusion.

In an AD that was published on January 2, 2026, the FAA said that it finalized the directive to address a potentially unsafe condition related to the HPT stage 1 and stage 2 disks of the GE90-90B, GE90-94B, GE90-110B1, and GE90-115B engines.

The engines power such aircraft as the Boeing 777-200ER, 777-200LR, 777F, and 777-300ER.

According to the United States regulator, an investigation by the manufacturer revealed that certain HPT stage 1 and stage 2 disks “were manufactured from powder metal material suspected to contain iron inclusion.”

The FAA detailed that further analysis showed that “the iron inclusion is attributed to deficiencies in the manufacturing process and may cause reduced material properties and a lower fatigue life capability, which may result in premature fracture and uncontained failure.”

“The manufacturer also informed the FAA that additional risk assessments revealed that there were no incidents of premature fracture and uncontained failure associated with the discovery of this iron inclusion material on these engines, but concluded that replacement of the affected HPT stage 1 and HPT stage 2 disks is necessary to prevent any future failure events.”

In comparison, when the FAA issued its NPRM to address the “increased risk of powder metal anomalies” in Pratt & Whitney PW1100G engines in December 2023, which is one of the engine options for Airbus A320neo family aircraft, the regulator pointed out that the initial directive, published in October 2022, was released followed “an analysis of an event involving an International Aero Engines AG [IAE] V2533-A5 model turbofan engine, which experienced an uncontained failure of an HPT 1st-stage disk that resulted in high-energy debris penetrating the engine cowling.”

The IAE V2500s are one of the options for the A320ceo family aircraft. The accelerated removals and inspections have plagued A320neo family aircraft operators to this day, with many airlines across the world having to deal with groundings of their aircraft due to the powder metal issue.

Nevertheless, in July 2025, when the FAA issued the notice of proposed rulemaking (NPRM) to address the iron inclusion on GE90s’ HPT stage 1 and stage 2 disks, it received comments from the Air Line Pilots Association, International (ALPA), Boeing, FedEx, and GE Aerospace. 

ALPA, Boeing, and FedEx supported the directive without change, while GE Aerospace requested the regulator to correct part numbers (P/Ns) of certain HPT disks.

Much like in July 2025, the FAA estimated that a single engine installed on a US-registered aircraft has a HPT stage 1 disk that needs to be replaced, as well as a single engine with a non-compliant HPT stage 2 disk. The US regulator has not provided an estimate on how many HPT disks would have to be replaced on aircraft registered outside of the US, which is not unusual.

According to the FAA’s estimates, the replacement of a HPT stage 1 and stage 2 disk should cost US operators $932,816 and $187,086 per engine, respectively. The estimated expenses include labor and part-related costs.

In the US, the only airlines with active specific subtype GE-90-powered passenger 777-200ER, 777-200LR, or 777-300ER aircraft are American Airlines and United Airlines.

The affected HPT stage 1 and stage 2 disks have to be replaced before further flight. Any disks that do not have the affected P/Ns have to be replaced at the next piece-part exposure or before exceeding 4,650 cycles since new (CSN, stage 1 disks) or 11,300 CSN (stage 2 disks).