FAA Finalises Airworthiness Directive for GE90 Engines Following Powder Metal Contamination Discovery

WASHINGTON, D.C. – The Federal Aviation Administration (FAA) has officially finalised a high-priority airworthiness directive (AD) targeting General Electric GE90 engines, the primary power plants for the Boeing 777 fleet. The ruling, published on January 2, 2026, addresses a critical manufacturing defect involving iron contamination in powder metal components that could lead to uncontained engine failures.

The directive follows a multi-year investigation by GE Aerospace, which revealed that specific high-pressure turbine (HPT) disks were manufactured using powder metal material suspected to contain "iron inclusion." This impurity can significantly reduce the fatigue life of engine components, potentially causing them to fracture prematurely.

The Technical Breakdown

The "iron inclusion" issue stems from deficiencies in the powder metal manufacturing process. In the high-stress, high-temperature environment of a jet engine, these microscopic contaminants act as stress concentrators, leading to the rapid development of cracks.

If a turbine disk fractures at cruising speed, it can result in an uncontained failure, where debris is ejected through the engine casing at high velocity, posing a direct threat to the aircraft's wings, fuel tanks, and fuselage.

"While there have been no reported incidents of premature fracture associated with this specific discovery on GE90 engines, the risk assessment concluded that the affected disks must be removed to ensure continued airworthiness," the FAA stated in its final rule.

Scope and Compliance Requirements

The AD, designated as AD 2025-25-07, becomes effective on February 6, 2026. It applies to GE90-90B, GE90-94B, GE90-110B1, and GE90-115B models. The mandate requires operators to replace affected HPT Stage 1 and Stage 2 disks based on specific usage thresholds:

Note: Any disks identified with high-risk serial numbers must be replaced before further flight.

Industry Impact and Operator Response

The FAA estimates that while the global impact involves dozens of aircraft, only a small number of engines on the U.S. registry are currently fitted with the specific non-compliant parts. Major operators of GE90-powered Boeing 777s, including American Airlines, United Airlines, and FedEx Express, have been working closely with GE Aerospace to phase out the affected hardware.

During the public comment period, Boeing, FedEx, and the Air Line Pilots Association (ALPA) expressed full support for the directive. GE Aerospace also proactively issued Service Bulletins (specifically SB 72-0926) to guide airlines through the inspection and replacement process.

The Broader Context

This directive is part of a larger industry-wide scrutiny of powder metal integrity. Similar contamination issues have plagued other major engine programs recently, most notably the Pratt & Whitney GTF (PW1100G) engines, which saw hundreds of Airbus A320neos grounded for inspections in 2024 and 2025.

By finalising this AD, the FAA aims to prevent the GE90 fleet from experiencing similar large-scale operational disruptions by mandating replacements before fatigue-related cracks can manifest.

Flight Safety Summary: FAA AD 2025-25-07