Airworthiness Directives; MHI RJ Aviation ULC (Type Certificate Previously Held by Bombardier, Inc.) Airplanes

Built by the Tribune's code from the Federal Register. No AI wrote this page. Published in the Federal Register March 6, 2026. Document 2026-04465. Updated Nov. 14, 2026.

What it does

The FAA is superseding Airworthiness Directive (AD) 2023-23- 02, which applied to all MHI RJ Aviation ULC Model CL-600-2B19 (Regional Jet Series 100 & 440), CL-600-2C10 (Regional Jet Series 700, 701 & 702), CL-600-2C11 (Regional Jet Series 550), CL-600-2D15 (Regional Jet Series 705), CL-600-2D24 (Regional Jet Series 900), and CL-600-2E25 (Regional Jet Series 1000) airplanes. AD 2023-23-02 required, for certain airplanes, revising the existing maintenance or inspection program, as applicable, to incorporate new or more restrictive airworthiness limitations; and accomplishing certain aircraft maintenance manual (AMM) tasks and corrective actions following short-term or long-term storage. Since the FAA issued AD 2023-23-02, additional power control unit (PCU) disconnect findings show that the task intervals must be reduced to allow earlier detection of potential single PCU disconnect cases. This AD continues to require certain actions in AD 2023-23-02 and requires repetitive operational checks of the rudder PCUs and repetitive operational tests of the elevator PCUs. 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 489 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

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

Since then:

What happens next and when

This AD is effective March 23, 2026.

The agency's dates, word for word.

Check it yourself

The record as published

Document number	2026-04465
Action	Final rule; request for comments.
Agencies	Transportation Department; Federal Aviation Administration
Published	March 6, 2026
Effective date	March 23, 2026
Comments close	April 20, 2026
Regulation identifier (RIN)	2120-AA64
Docket	FAA-2026-2285

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