EASA AD CF-2021-53: NOT ELIGIBLE FOR ADOPTION - EASA POSITION ATTACHED

What to do

Affected operators must revise the Limitations Section of their Rotorcraft Flight Manual to incorporate the new restrictions against using radio altimeter data in the presence of 5G C-Band interference as identified by NOTAMs. Flight crews must be informed of these limitations and comply with them immediately. Compliance with these requirements is mandatory as of the effective date, 2022-01-04.

Summary

Canadian Airworthiness Directive CF-2021-53 addresses the risk of interference to radio altimeters on helicopters from 5G C-Band wireless broadband signals. It applies to all helicopters certified by Airbus Helicopters, Airbus Helicopters Deutschland GmbH, Bell Textron Canada Limited, Hélicoptères Guimbal, and Leonardo S.p.a. equipped with radio altimeters. The directive prohibits certain operations requiring radio altimeter data when 5G C-Band interference is present, particularly in U.S. airspace.

What changed

This new Airworthiness Directive introduces operational limitations for Canadian-registered rotorcraft to mitigate risks from 5G C-Band interference affecting radio altimeters. It mandates revising the Rotorcraft Flight Manual to include prohibitions on operations such as approaches, hover autopilot modes, and takeoffs or landings that rely on radio altimeter data when 5G interference is indicated by NOTAMs. The directive aligns Canadian requirements with FAA AD 2021-23-13 for operations in U.S. airspace.

Why it matters

This directive is critical for aviation professionals because 5G C-Band signals can cause radio altimeters to malfunction or provide misleading data, potentially compromising flight safety during low altitude operations. Operators, maintenance, and compliance teams must ensure rotorcraft are operated within the new limitations to avoid unsafe conditions. It also affects flight planning and crew training due to the need to use barometric minimums instead of radio altimeter minimums in affected areas.