# Proposed AD FAA-2011-0996: The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER Series Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2011-26-09
- Products: Boeing
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: October 5, 2011, 76 FR 61643
- Comments due: November 21, 2011
- Became: [AD 2011-26-09](https://openairdocs.org/ad/2011-26-09)
- Docket: FAA-2011-0996 (https://www.regulations.gov/docket/FAA-2011-0996, where comments are filed)
- Project: 2011-NM-068-AD
- FR document: 2011-25579
- Official PDF: https://openairdocs.org/files/sha256/fc/bd/fcbd0cbc6ab05c55f765f619ecd718f89bffe007c9fcecdefb519f2e53173f48 (from https://www.govinfo.gov/content/pkg/FR-2011-10-05/pdf/2011-25579.pdf)
- Federal Register: https://www.federalregister.gov/documents/2011/10/05/2011-25579/airworthiness-directives-the-boeing-company-model-737-600--700--700c--800--900-and--900er-series
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/673095E650FF6F5686257920004E2C32.0001
- Page: https://openairdocs.org/proposed/FAA-2011-0996

## Summary

We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD would require replacement of the thumbnail fairing edge seals on both sides of the engines with Nitronic 60 stainless steel alloy seals. This proposed AD was prompted by reports of excessive in-service wear damage of the thumbnail fairing edge seal and the fan cowl panel rub strip and fan cowl skin assembly. We are proposing this AD to prevent failure of the fire seal, which could allow a fire in the fan compartment to spread beyond the firewall and reach the flammable fluid leakage zones, resulting in an uncontrolled fire.

## Notices in this docket

- Oct 5, 2011: Notice of proposed rulemaking (NPRM). (first notice), FR document 2011-25579, comments due Nov 21, 2011 (https://www.federalregister.gov/documents/2011/10/05/2011-25579/airworthiness-directives-the-boeing-company-model-737-600--700--700c--800--900-and--900er-series)

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