# Proposed AD FAA-2021-0258: The Boeing Company Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2021-14-10
- Products: Boeing
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: April 13, 2021, 86 FR 19160
- Comments due: May 28, 2021
- Became: [AD 2021-14-10](https://openairdocs.org/ad/2021-14-10)
- Docket: FAA-2021-0258 (https://www.regulations.gov/docket/FAA-2021-0258, where comments are filed)
- Project: AD-2020-01565-T
- FR document: 2021-07544
- Official PDF: https://openairdocs.org/files/sha256/7b/53/7b53cc8018637023060b99887e32c8ef67f63bfe4477075162d837df71674e06 (from https://www.govinfo.gov/content/pkg/FR-2021-04-13/pdf/2021-07544.pdf)
- Federal Register: https://www.federalregister.gov/documents/2021/04/13/2021-07544/airworthiness-directives-the-boeing-company-airplanes
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/796F48615E83049A862586B6007725C2.0001
- Page: https://openairdocs.org/proposed/FAA-2021-0258

## Summary

The FAA proposes to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 747-400, 747-400D, and 747-400F series airplanes. This proposed AD was prompted by reports of burned Boeing Material Specification (BMS) 8-39 urethane foam found in certain locations on the airplane; investigation revealed that the fire- retardant properties degrade with age. This proposed AD would require inspecting the insulation blankets in certain areas of the forward cargo compartment for exposed BMS 8-39 urethane foam, not encapsulated by a protective fire resistant barrier, and for seal integrity, and replacing the BMS 8-39 urethane foam and seal if necessary. The FAA is proposing this AD to address the unsafe condition on these products.

## Notices in this docket

- Apr 13, 2021: Notice of proposed rulemaking (NPRM). (first notice), FR document 2021-07544, comments due May 28, 2021 (https://www.federalregister.gov/documents/2021/04/13/2021-07544/airworthiness-directives-the-boeing-company-airplanes)

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