Airworthiness Directives; Airbus Helicopters Deutschland GmbH (AHD) Helicopters

Built by the Tribune's code from the Federal Register. No AI wrote this page. Published in the Federal Register March 13, 2026. Document 2026-04921. Updated Nov. 13, 2026.

What it does

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.

The Federal Aviation Administration's summary, as published in the Federal Register.

What changed in the regulation

1 part of Title 14 of the Code of Federal Regulations:

14 CFR 39

Wording on eCFR: the day before it took effect and from the day it took effect (first part listed).

Compared with

The Federal Aviation Administration has published 488 final rules in 2026 so far, compared with 518 in all of 2025.

Counted by the Tribune from Federal Register records since Jan. 1, 2025.

Before this

692 earlier Federal Register documents under regulation identifier 2120-AA64 since Jan. 1, 2025.

March 13, 2026 Notice of proposed rulemaking (NPRM). Airworthiness Directives; The Boeing Company Airplanes
March 13, 2026 Final rule. Airworthiness Directives; Airbus Helicopters
March 13, 2026 Notice of proposed rulemaking (NPRM). Airworthiness Directives; Various Helicopters
March 13, 2026 Final rule. Airworthiness Directives; Airbus Helicopters
March 12, 2026 Final rule. Airworthiness Directives; The Boeing Company Airplanes
March 12, 2026 Final rule. Airworthiness Directives; The Boeing Company Airplanes
March 12, 2026 Final rule; request for comments. Airworthiness Directives; Airbus SAS Airplanes
March 12, 2026 Final rule. Airworthiness Directives; The Boeing Company Airplanes

Since then:

What happens next and when

This AD is effective April 17, 2026.

The agency's dates, word for word.

Check it yourself

The record as published

Document number	2026-04921
Action	Final rule.
Agencies	Transportation Department; Federal Aviation Administration
Published	March 13, 2026
Effective date	April 17, 2026
Regulation identifier (RIN)	2120-AA64
Docket	FAA-2025-5393

Source: the Federal Register (public domain). The document in the Federal Register