Federal Aviation Administration April 12, 2023 – Federal Register Recent Federal Regulation Documents

The FAA proposes to supersede Airworthiness Directive 2021-23- 13, which applies to all helicopters equipped with a radio (also known as radar) altimeter. AD 2021-23-13 requires revising the limitations section of the existing rotorcraft flight manual (RFM) for your helicopter to incorporate limitations prohibiting certain operations requiring radio altimeter data when in the presence of 5G C-Band interference in areas as identified by Notices to Air Missions (NOTAMs). Since the FAA issued AD 2021-23-13, the FAA determined that additional limitations are needed due to the continued deployment of new 5G C-Band base stations whose signals are expected to cover most of the contiguous United States at transmission frequencies between 3.7- 3.98 GHz. This proposed AD would require revising the limitations section of the existing RFM to incorporate limitations prohibiting certain operations requiring radio altimeter data, due to the presence of 5G C-Band interference. The FAA is proposing this AD to address the unsafe condition on these products.