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Data / Federal rules / 2026-04921

Airworthiness Directives; Airbus Helicopters Deutschland GmbH (AHD) Helicopters

The Federal Aviation Administration published this final rule in the Federal Register on March 13, 2026. It took effect on April 17, 2026.

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What the agency says

The FAA is adopting a new airworthiness directive (AD) for all Airbus Helicopters Deutschland GmbH (AHD) Model MBB-BK 117 A-1, MBB-BK 117 A-3, MBB-BK 117 A-4, MBB-BK 117 B-1, MBB-BK 117 B-2, and MBB-BK 117 C-1 helicopters. This AD was prompted by a report of a main rotor head (MRH) having the same part number (P/N) and serial number (S/N) as another MRH due to incorrect modification instructions where the modified part S/N was not re-identified and the MRH can be operated with the wrong associated log card if accidently interchanged. This AD requires performing a one-time consistency check of the P/N and S/N of the MRH, performing corrective actions if applicable, determining if the MRH has been modified, and re-identifying the modified MRH. This AD also allows replacing the MRH as an optional action and prohibits the installation of an affected MRH on any helicopter. The FAA is issuing this AD to address the unsafe condition on these products.

Key facts

Document number
2026-04921
Type
Final rule
Action
Final rule
Agency
Transportation Department; Federal Aviation Administration
Published
March 13, 2026
Takes effect
April 17, 2026
Dates
This AD is effective April 17, 2026.
Docket
Docket No. FAA-2025-5393; Project Identifier MCAI-2025-00157-R; Amendment 39-23277; AD 2026-05-04
Regulation ID (RIN)
2120-AA64
Code of Federal Regulations
14 CFR 39
Topics
Air transportation; Aircraft; Aviation safety; Incorporation by reference; Safety
Pages
3

The document on federalregister.gov PDF

Other documents from the Federal Aviation Administration

Everything from the Federal Aviation Administration · Rules on air transportation · Rules on aircraft · Rules on aviation safety · Published in March 2026

Read from the Federal Register API, last updated 2026-10-23. The document on federalregister.gov is the official record; dates and dockets can change through later corrections. Free to reuse with credit to SpecStream under CC BY 4.0.