# Airworthiness Directives; Transport and Commuter Category Airplanes
> **Rule** · Final rule; request for comments. · Published 2026-06-30 · Effective 2026-07-01 · 91 FR 39399
## Document
- **Document number:** 2026-13162
- **Category:** airworthiness
- **Manufacturer:** Transport and Commuter Category
- **Type:** Rule
- **Action:** Final rule; request for comments.
- **Citation:** 91 FR 39399
- **Publication date:** 2026-06-30
- **Effective date:** 2026-07-01
- **FAA docket:** Docket No. FAA-2026-4659
## Abstract

The FAA is adopting a new airworthiness directive (AD) for all transport and commuter category airplanes equipped with a radio (also known as radar) altimeter. This AD was prompted by the determination that radio altimeters cannot be relied upon to perform their intended function if they experience interference from wireless broadband operations in the 3.7-3.98 GHz frequency band (5G Lower C-Band) while operating in Canadian airspace. This AD requires revising the existing airplane flight manual (AFM) to incorporate limitations prohibiting certain operations requiring radio altimeter data when operating within the Canadian airspace. The FAA is issuing this AD to address the unsafe condition on these products.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2026/06/30/2026-13162/airworthiness-directives-transport-and-commuter-category-airplanes)
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