EASA AD US-2021-26-04
Engine - Fan Hub Assembly - Inspection / Replacement
Summary
The Federal Aviation Administration's Airworthiness Directive 2021-26-04 addresses Engine Alliance GP7270 and GP7277 model turbofan engines. This directive mandates inspections and potential replacement of the engine fan hub assembly to prevent uncontained engine failures. It applies specifically to engine fan hub assemblies with part numbers 5760221, 5760321, or 5760001.
What Changed
AD 2021-26-04 supersedes AD 2019-18-08 by lowering the repetitive eddy current inspection (ECI) intervals and adding ultrasonic test (UT) inspections of the fan hub rim area. It also requires independent inspections during disassembly and reassembly of the engine fan hub blade lock assembly and mandates replacement of the fan hub assembly if damage exceeds serviceable limits.
Why It Matters
This directive is critical for aviation professionals to detect cracks and damage in engine fan hub assemblies that could lead to uncontained engine failures. Compliance ensures continued airworthiness and safety of aircraft powered by Engine Alliance GP7270 and GP7277 engines. Maintenance, repair, and overhaul (MRO) teams must adjust inspection schedules and procedures accordingly to meet updated safety standards.
What To Do
Operators and maintenance personnel must perform initial and repetitive eddy current and ultrasonic inspections of the engine fan hub assembly as specified. Independent visual inspections are required during the next disassembly and reassembly of the fan hub blade lock assembly. If damage is found beyond allowable limits, the engine fan hub assembly must be replaced with a serviceable part. Compliance with these requirements is effective January 12, 2022, and comments on the directive are accepted until February 11, 2022.
AI-generated summary from official EASA source document. Always verify against the original.