Federal Register #20260706

FAA Mandates Inspections and Part Replacements for Pratt & Whitney Engines

The Federal Aviation Administration (FAA) is mandating new safety inspections and part replacements for specific Pratt & Whitney engine models to address risks of turbine disk failure. - Government Buyer: - Federal Aviation Administration (FAA), Aircraft Certification Service - OEMs and Vendors: - Pratt & Whitney (primary OEM for affected engines) - International Aero Engines, LLC (referenced in incident prompting directive) - Collins Aerospace (referenced for service bulletin compliance) - Products/Services Requested: - Repetitive angled ultrasonic inspections (AUSIs) of high-pressure turbine (HPT) 1st-stage disks (part numbers: 1B7801, 1B3601, 1B3601001) - Repetitive AUSIs of turbine hubs (part numbers: 1B4902, 1B6602, 1B8002) - Removal and replacement of HPT lenticular seal assemblies (part number: 1B8575; quantity: 14 identified by serial number) - Unique or Notable Requirements: - Inspections and removals are required at the next piece-part exposure and at every subsequent exposure - HPT lenticular seal assemblies must be removed before reaching 2,750 cycles since new or at next exposure, whichever comes first - Compliance with Collins Aerospace Alert Service Bulletin SB 9613005 is required - Optional terminating action includes updating the airworthiness limitations section (ALS) of engine manuals - Actions are driven by inspection results and affected engine models, not by fixed quantities - Purpose is to prevent uncontained disk failure and enhance operational safety

Description

The FAA is adopting a new airworthiness directive (AD) for certain Pratt & Whitney Model F117-PW-100, PW2037, PW2037D, PW2037M, PW2040, and PW2040D engines. This AD was prompted by an updated analysis of an event involving an International Aero Engines Model PW1127GA-JM engine that experienced a high-pressure compressor 7th-stage integrally bladed rotor separation resulting in engine shutdown and aborted takeoff. The directive requires repetitive angled ultrasonic inspections of certain high-pressure turbine 1st-stage disks and turbine hubs for crack indications, removal and replacement if necessary, and removal of certain high-pressure turbine lenticular seal assemblies. The AD aims to address the unsafe condition on these engines to prevent engine failure.

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