# Proposed AD FAA-2012-1109: The Boeing Company Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2013-10-02
- Products: Boeing
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: October 29, 2012, 77 FR 65506
- Comments due: December 13, 2012
- Became: [AD 2013-10-02](https://openairdocs.org/ad/2013-10-02)
- Docket: FAA-2012-1109 (https://www.regulations.gov/docket/FAA-2012-1109, where comments are filed)
- Project: 2011-NM-172-AD
- FR document: 2012-26477
- Official PDF: https://openairdocs.org/files/sha256/9e/4a/9e4aecd1270c7941c2cfcce1349f2fff5ce650b45132b8236cb66216b1323e8a (from https://www.govinfo.gov/content/pkg/FR-2012-10-29/pdf/2012-26477.pdf)
- Federal Register: https://www.federalregister.gov/documents/2012/10/29/2012-26477/airworthiness-directives-the-boeing-company-airplanes
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/6D0782F81042E6CB86257AA6004C2851.0001
- Page: https://openairdocs.org/proposed/FAA-2012-1109

## Summary

We propose to supersede an existing airworthiness directive (AD) that applies to certain The Boeing Company Model 757-200 and - 200PF series airplanes. The existing AD currently requires modification of the nacelle strut and wing structure, and repair of any damage found during the modification. Since we issued that AD, a compliance time error involving the optional threshold formula was discovered, which could allow an airplane to exceed the acceptable compliance time for addressing the unsafe condition. This proposed AD would specify a maximum compliance time limit that overrides the optional threshold formula results. We are proposing this AD to prevent fatigue cracking in primary strut structure and consequent reduced structural integrity of the strut.

## Notices in this docket

- Oct 29, 2012: Notice of proposed rulemaking (NPRM). (first notice), FR document 2012-26477, comments due Dec 13, 2012 (https://www.federalregister.gov/documents/2012/10/29/2012-26477/airworthiness-directives-the-boeing-company-airplanes)

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