WASHINGTONFAA is warning that 5G emissions could interfere with radio altimeters in most Boeing 737 jets and impact airplane landings.

The Federal Aviation Administration's directive affects all Boeing 737 family jets except its 200 and 200-c series, a Federal Register notice posted online on Wednesday said.

It added that their "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)."

The FAA said in the notice, scheduled to be formally published on Thursday, that regulators had determined that "during the approach, landings, and go-arounds, as a result of this interference, certain airplane systems may not properly function".

That would result in "increased light crew workload while on approach with the flight director, autothrottle, or autopilot engaged, which could result in a reduced ability of the flight crew to maintain safe flight and landing of the airplane," it said.

A Boeing spokesman said in a statement: "We support the Airworthiness Directive, as it mandates the same guidance that Boeing provided to operators back in January".

Telecommunications networks are rolling out next-generation 5G systems that the FAA has previously warned could impact sensitive airplane electronics such as radio altimeters.

The Federal Communications Commission and the National Telecommunications and Information Administration (NTIA) have vowed to improve coordination on spectrum management after a dispute over 5G aviation.

The spectrum rolled out in January, but only after Verizon Communications and AT&T agreed to delay deploying 5G wireless towers near airports.