EASA AD US-2023-18-04
Forward Outer Seals, High Pressure Turbine Rotor Stage 1 Discs and Rotating Seals - Replacement
Summary
The Federal Aviation Administration's Airworthiness Directive 2023-18-04 mandates replacement of certain forward outer seals, high-pressure turbine rotor (HPTR) stage 1 disks, and rotating seals on General Electric Company Model CF6-80E1A2, CF6-80E1A3, CF6-80E1A4, and CF6-80E1A4/B engines. This directive addresses parts suspected to contain iron inclusion, which could reduce material strength and fatigue life. The directive aims to prevent uncontained engine failures and potential damage to aircraft.
What Changed
This new airworthiness directive requires removal and replacement of specific forward outer seals, HPTR stage 1 disks, and rotating seals identified by part and serial numbers due to suspected material defects. It introduces mandatory compliance times, including immediate removal of affected HPTR stage 1 disks before further flight and removal of other parts at the next piece-part exposure or before reaching specified cycle limits. The directive also clarifies that removed parts are not eligible for reinstallation.
Why It Matters
This directive is critical for aviation professionals to prevent engine failures caused by material defects in key turbine components. Operators and maintenance organizations must ensure timely identification and replacement of affected parts to maintain engine airworthiness and avoid uncontained failures. Compliance reduces safety risks and potential costly damage to aircraft and engines.
What To Do
Operators of affected GE CF6-80E1 engine models must remove and replace the specified forward outer seals before 5,400 cycles since new or at the next piece-part exposure, rotating seals before 5,200 cycles since new or at the next piece-part exposure, and HPTR stage 1 disks immediately before further flight after October 19, 2023. Parts removed must not be reinstalled. Stakeholders should review engine records for affected part numbers and serial numbers and coordinate replacements accordingly.
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