# Proposed AD FAA-2005-20947: Learjet Model 23, 24, 24A, 24B, 24B-A, 24D, 24D-A, 24E, 24F, 25, 25A, 25B, 25C, 25D, and 25F Airplanes Modified by Supplemental Type Certificate SA1731SW, SA1669SW, or SA1670SW

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2005-23-06
- Products: Learjet
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: April 14, 2005, 70 FR 19718
- Comments due: May 31, 2005
- Became: [AD 2005-23-06](https://openairdocs.org/ad/2005-23-06)
- Docket: FAA-2005-20947 (https://www.regulations.gov/docket/FAA-2005-20947, where comments are filed)
- Project: 2004-NM-245-AD
- FR document: 05-7484
- Official PDF: https://openairdocs.org/files/sha256/bb/97/bb97f851b99e8bd7ba473c9b28f43b10a050e8c40b017f6c6d22186fad17537d (from https://www.govinfo.gov/content/pkg/FR-2005-04-14/pdf/05-7484.pdf)
- Federal Register: https://www.federalregister.gov/documents/2005/04/14/05-7484/airworthiness-directives-learjet-model-23-24-24a-24b-24b-a-24d-24d-a-24e-24f-25-25a-25b-25c-25d-and
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/2173E9A3174D1E5686256FE3005747D6.0001
- Page: https://openairdocs.org/proposed/FAA-2005-20947

## Summary

The FAA proposes to adopt a new airworthiness directive (AD) for certain Learjet Model 23, 24, 24A, 24B, 24B-A, 24D, 24D-A, 24E, 24F, 25, 25A, 25B, 25C, 25D, and 25F airplanes. This proposed AD would require removing the thrust reverser accumulator, and making the thrust reverser hydraulic system and the thrust reversers inoperable. This proposed AD is prompted by reports of the failure of two thrust reverser accumulators. We are proposing this AD to prevent failure of the thrust reverser accumulators, due to fatigue cracking on the female threads, which could result in the loss of hydraulic power and damage to the surrounding airplane structure.

## Notices in this docket

- Apr 14, 2005: Notice of proposed rulemaking (NPRM). (first notice), FR document 05-7484, comments due May 31, 2005 (https://www.federalregister.gov/documents/2005/04/14/05-7484/airworthiness-directives-learjet-model-23-24-24a-24b-24b-a-24d-24d-a-24e-24f-25-25a-25b-25c-25d-and)

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