# Airworthiness Directives; The Boeing Company Airplanes
> **Rule** · Final rule. · Published 2021-07-15 · Effective 2021-08-19 · 86 FR 37224
## Document
- **Document number:** 2021-15027
- **Category:** airworthiness
- **Manufacturer:** The Boeing Company
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 86 FR 37224
- **Publication date:** 2021-07-15
- **Effective date:** 2021-08-19
- **FAA docket:** Docket No. FAA-2021-0258
## Abstract

The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 747-400, 747-400D, and 747-400F series airplanes. This 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 AD requires 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 issuing this AD to address the unsafe condition on these products.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2021/07/15/2021-15027/airworthiness-directives-the-boeing-company-airplanes)
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