The Federal Aviation Administration (FAA) has warned the existing fleet of Boeing 737s are still susceptible to 5G interference.
Verizon and AT&T spent billions buying C-band spectrum for their 5G networks at a recent FCC auction, only to have the FAA and airline industry raise concerns about 5G interference. Because C-band spectrum is so close to the spectrum aircraft altimeters use, there were concerns 5G could interfere with those altimeters, leading to significant dangers during flights, and especially when taking off and landing.
Despite eventually coming to terms that allowed Verizon and AT&T to continue with their deployment, the FAA has issued an Airworthiness Directive (AD), indicating that Boeing 737s are still particularly susceptible to interference.
This AD was prompted by a 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 C-Band), and a recent determination that, during approach, landings, and go-arounds, as a result of this interference, certain airplane systems may not properly function, resulting in increased flightcrew workload while on approach with the flight director, autothrottle, or autopilot engaged, which could result in reduced ability of the flightcrew to maintain safe flight and landing of the airplane.
It’s currently unclear what, if any, mitigation efforts may be taken.
