EASA AD US-2022-12-12
Engine - Low Pressure Turbine Stage 5 Air Seal - Replacement
Summary
The document titled "Engine - Low Pressure Turbine Stage 5 Air Seal - Replacement" is a Federal Aviation Administration (FAA) Airworthiness Directive (AD) addressing certain Pratt & Whitney PW4062 model turbofan engines. It mandates the removal and replacement of the low-pressure turbine (LPT) stage 5 air seal due to a manufacturing defect that reduces its low-cycle fatigue life. This AD aims to prevent potential engine damage and uncontained part release that could compromise aircraft safety.
What Changed
This new AD introduces a requirement to remove and replace the LPT stage 5 air seal, part number 50N324, on affected PW4062 engines with a part eligible for installation. The affected air seals have a reduced fatigue life limit from 15,000 cycles to 8,240 cycles due to insufficient cooling during manufacturing. The AD applies to specific serial numbers listed in the directive and is effective immediately with compliance required at the next piece-part exposure or before reaching 8,240 cycles since new.
Why It Matters
This AD is critical for aviation professionals as it addresses a safety risk involving premature fatigue failure of a key engine component. Operators and maintenance organizations must ensure timely replacement of the affected air seals to avoid uncontained engine failures that could lead to significant aircraft damage and safety hazards. Compliance teams need to track affected serial numbers and manage maintenance schedules accordingly to meet the directive's requirements.
What To Do
Operators of Pratt & Whitney PW4062 engines with the affected LPT stage 5 air seals must remove and replace these parts at the next piece-part exposure or before the air seal accumulates 8,240 cycles since new, whichever occurs first. Replacement parts must be those not listed as affected serial numbers. Stakeholders should also submit any comments on the AD by August 1, 2022, as invited by the FAA.
Your fleet's weekly compliance brief
AI-summarized regulatory changes, compliance deadlines, and action items — filtered to your aircraft, every Monday.
AI-generated summary from official EASA source document. Always verify against the original.