Why aviation and telecom companies like Verizon and AT&T are warring over the rollout of 5G, which opponents say can lead to flight delays and cancellations

• Airlines and aircraft manufacturers are raising concerns over the rollout of 5G communications.
• The current 5G rollout may affect an aircraft's radio altimeter, used to determine altitude above ground level in critical scenarios such as landings.

The new year is bringing new challenges for the aviation industry.

Telecommunications giants are planning the long-awaited rollout of 5G communications aimed at improving wireless connectivity in the US. But the plan is meeting strong pushback from the airlines, aircraft manufacturers, and aviation trade organizations that say 5G may adversely impact aviation safety.

One key issue is how the deployment of 3.7-3.98 GHz 5G C-Band communications will affect radar altimeters on aircraft, also known as radio altimeters.

The Radio Technical Commission for Aeronautics describes radio altimeters as "the only sensor onboard a civil aircraft which provides a direct measurement of the clearance height of the aircraft over the terrain or other obstacles."

Aircraft flying over mountainous terrain, for example, might rely on radio altimeters to gauge their distance from the surface. And aircraft may also use radio altimeters when landing to gauge their altitude above ground level compared to their altitude above mean sea level.

Opponents claim 5G communications may interfere with the altimeters during critical phases of flight. The RTCA stated that "failures of these sensors can therefore lead to incidents with catastrophic results resulting in multiple fatalities," in its report analyzing the impact of expanded 5G communications on aviation.

One such example, highlighted by the House of Representatives Committee on Transportation and Infrastructure, is the Turkish Airlines Boeing 737-800 which suffered a fatal crash in 2009 after receiving an "erroneous altitude reading" from one of its radio altimeters, as the Dutch Safety Board wrote.

The Federal Aviation Administration in early December specifically addressed potential issues raised by 5G's rollout by issuing regulations known as "airworthiness directives." Airlines and other aircraft operators, as a result, are required to limit operations that require a radio altimeter when "in the presence of 5G C-Band interference."

"This [airworthiness directive] 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)," the FAA wrote.

But airlines say that complying with the new requirements will greatly disrupt normal operations. Airlines for America, the trade organization representing some of the country's largest airlines, surveyed its member airlines and issued a scathing report on how 5G may impact flights in 2022.

"For example, if the AD were applied in arrears to A4A members' 2019 operations, approximately 345,000 passenger flights, 32 million passengers, and 5,400 cargo flights would have been impacted in the form of delayed flights, diversions, or cancellations," the organization said.

Boeing and Airbus' American division, using Airlines for America's findings, sent a letter to Transportation Secretary Pete Buttigieg asking for 5G deployment to be delayed.

"We agree that 5G interference could adversely affect the ability of aircraft to safely operate," Boeing CEO Dave Calhoun and Airbus Americas CEO Jeffrey Knittel wrote in a letter viewed by Reuters.

Verizon Communications, a 5G leader, pointed to other countries in which 5G and aviation currently co-exist as evidence against the aviation industry's concerns.

"Air safety is of paramount importance, but there is no evidence that 5G operations using C-Band spectrum pose any risk to aviation safety, as the real-world experience in dozens of countries already using this spectrum for 5G confirms," a Verizon spokesperson told Bloomberg.

Airlines for America work with the Aerospace Industries Association, a trade association representing aircraft manufacturers and suppliers, and CTIA, the trade organization representing wireless companies, on a new data-sharing partnership aimed at identifying problem areas in the 5G rollout.

"The best technical experts from across both industries will be working collectively to identify a path forward, in coordination with the FAA and FCC," the trio wrote in a statement provided to Insider. "Our belief is that by working collaboratively in good faith on a data-driven solution, we can achieve our shared goal of deploying 5G while preserving aviation safety."

Airlines for America held short of filling an emergency lawsuit on Monday to stop the January 5 rollout and instead announced an agreement with AT&T and Verizon to delay 5G implementation until January 19.

The rollout will proceed on that date but the following months would then see the DOT and FAA review the data to determine mitigation efforts for airports.

"We know aviation safety and 5G can co-exist and we are confident further collaboration and technical assessment will allay any issues," AT&T said in a statement.