# Proposed AD FAA-2024-2539: Pratt & Whitney Canada Corp. Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2025-05-13
- Products: Pratt & Whitney Canada
- Product type: Engine
- Action: Notice of proposed rulemaking (NPRM).
- Published: November 26, 2024, 89 FR 93225
- Comments due: January 10, 2025
- Became: [AD 2025-05-13](https://openairdocs.org/ad/2025-05-13)
- Docket: FAA-2024-2539 (https://www.regulations.gov/docket/FAA-2024-2539, where comments are filed)
- Project: MCAI-2023-00971-E
- FR document: 2024-27659
- Official PDF: https://openairdocs.org/files/sha256/66/7c/667c4f1daf0ab8db4cbb11f7de2f5a3f91ccb73dfb375039b4eca3bfce752364 (from https://www.govinfo.gov/content/pkg/FR-2024-11-26/pdf/2024-27659.pdf)
- Federal Register: https://www.federalregister.gov/documents/2024/11/26/2024-27659/airworthiness-directives-pratt-and-whitney-canada-corp-engines
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/FR-ADNPRM-2024-27659-00000000000.0001
- Page: https://openairdocs.org/proposed/FAA-2024-2539

## Summary

The FAA proposes to adopt a new airworthiness directive (AD) for certain Pratt & Whitney Canada Corp. (P&WC) Model PW535E and PW535E1 engines. This proposed AD was prompted by a manufacturer design review that indicated certain flange bolts securing the gas generator case and turbine support case are susceptible to cracking at their current low-cycle fatigue (LCF) life. This proposed AD would require repetitive borescope inspections (BSI) of the gas generator case to turbine support case retaining bolts for evidence of bolt cracks, bolt fracture, missing bolts, or loose bolts and replacement, if necessary, as specified in a Transport Canada AD, which is incorporated by reference. The FAA is proposing this AD to address the unsafe condition on these products.

## Notices in this docket

- Nov 26, 2024: Notice of proposed rulemaking (NPRM). (first notice), FR document 2024-27659, comments due Jan 10, 2025 (https://www.federalregister.gov/documents/2024/11/26/2024-27659/airworthiness-directives-pratt-and-whitney-canada-corp-engines)

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