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AD 2025-03401

Published 2025-03-04 · 2 models · 101 US-registered tails affected · Federal Register

Airworthiness Directives; The Boeing Company Airplanes Federal Register ↗

Abstract

The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. This AD was prompted by two engine fan blade-out (FBO) events that resulted in the separation of engine inlet cowl and fan cowl parts from the airplane. In one event, fan cowl parts damaged the fuselage, which caused loss of pressurization and subsequent emergency descent. This AD requires replacing specified inlet cowl aft bulkhead fasteners for certain airplanes; for certain other airplanes, inspecting the inlet cowl aft bulkhead fastener and replacing the fasteners if rivets are found, and, for all airplanes, replacement of the crushable spacers used in the attachment of the inlet cowl to the engine fan case; or as an option, installing a serviceable inlet cowl. This AD also requires revising the existing maintenance or inspection program, as applicable, to incorporate new airworthiness limitations (AWLs). The FAA is issuing this AD to address the unsafe condition on these products.

Applicability · by US fleet size

Federal Register text

Verbatim; the Federal Register publication is the legally binding document. Cite: 90 FR 11103. View on Federal Register ↗

[Federal Register Volume 90, Number 41 (Tuesday, March 4, 2025)] [Rules and Regulations] [Pages 11103-11109] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 2025-03401]

[[Page 11103]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-2236; Project Identifier AD-2023-00962-T; Amendment 39-22959; AD 2025-04-01] RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. This AD was prompted by two engine fan blade-out (FBO) events that resulted in the separation of engine inlet cowl and fan cowl parts from the airplane. In one event, fan cowl parts damaged the fuselage, which caused loss of pressurization and subsequent emergency descent. This AD requires replacing specified inlet cowl aft bulkhead fasteners for certain airplanes; for certain other airplanes, inspecting the inlet cowl aft bulkhead fastener and replacing the fasteners if rivets are found, and, for all airplanes, replacement of the crushable spacers used in the attachment of the inlet cowl to the engine fan case; or as an option, installing a serviceable inlet cowl. This AD also requires revising the existing maintenance or inspection program, as applicable, to incorporate new airworthiness limitations (AWLs). The FAA is issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective April 8, 2025. The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of April 8, 2025.