Airworthiness Directives; Various Helicopters
Key claim: The FAA would require helicopter operators to update flight manuals so that certain radio-altimeter-dependent operations are prohibited in Canadian airspace, because 5G C-band wireless signals there can make those altimeters unreliable.
Abstract
(Proposed Rule · Transportation Department, Federal Aviation Administration) The FAA proposes to adopt a new airworthiness directive (AD) for all helicopters equipped with a radio (also known as radar) altimeter. This proposed 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 to 3.98 GHz frequency band (5G Lower C-Band) while operating in Canadian airspace. This proposed AD would require revising the existing rotorcraft flight manual (RFM) for the helicopter to incorporate limitations prohibiting certain operations requiring radio altimeter data when operating within Canadian airspace. The FAA is proposing this AD to address the unsafe condition on these products.
Why this matters
The proposed AD extends the FAA’s 5G C-band radio-altimeter interference regime from a U.S.-airspace concern into cross-border operations, acknowledging that Canadian wireless deployments create the same altimeter-reliability risk for helicopters. It shows that until codified interference-tolerance performance standards take full effect later this decade, the FAA continues to manage altimeter-5G coexistence through flight-manual prohibitions on specific operations. The scope is narrow — certain helicopter operations in Canadian airspace — but it fills a geographic gap in an otherwise U.S.-focused mitigation framework.