# Proposed AD FAA-2026-4668: The Boeing Company Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Comment period closed
- Products: Boeing 747-400 Series
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: June 30, 2026, 91 FR 39573
- Comments due: August 14, 2026
- Docket: FAA-2026-4668 (https://www.regulations.gov/docket/FAA-2026-4668, where comments are filed)
- Project: AD-2025-01680-T
- FR document: 2026-13129
- Official PDF: https://openairdocs.org/files/sha256/f7/50/f7508695aedc6e407571197edac0406a550d513d96e890826eb8b1cd03a7db5e (from https://www.govinfo.gov/content/pkg/FR-2026-06-30/pdf/2026-13129.pdf)
- Federal Register: https://www.federalregister.gov/documents/2026/06/30/2026-13129/airworthiness-directives-the-boeing-company-airplanes
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/FR-ADNPRM-2026-13129-00000000000.0001
- Page: https://openairdocs.org/proposed/FAA-2026-4668

## Summary

The FAA proposes to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 747-400 series airplanes. This proposed AD was prompted by reports of potable water leaking into the electrical equipment bay cooling air inlet. This proposed AD would require performing repetitive inspections of potential water sources from the upper deck and the main deck, including potable water and waste water lines, for any water leaks and clogs, and applicable on- condition actions. The FAA is proposing this AD to address the unsafe condition on these products.

## Notices in this docket

- Jun 30, 2026: Notice of proposed rulemaking (NPRM). (first notice), FR document 2026-13129, comments due Aug 14, 2026 (https://www.federalregister.gov/documents/2026/06/30/2026-13129/airworthiness-directives-the-boeing-company-airplanes)

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