At the eleventh hour, mobile service providers AT&T and Verizon agreed to a partial delay in activating their 5G networks following pressure from industry and government.
In the United States, 5G services are planned for launch beginning January 19 using frequencies in a radio spectrum called the C-band. These frequencies can be close to those used by radar altimeters, an important piece of safety equipment in aircraft.
Because the proposed 5G deployment involves a new combination of power levels, frequencies, proximity to flight operations, and other factors, the Federal Aviation Administration (FAA) will impose restrictions on flight operations using certain types of radar altimeter equipment close to antennas in 5G networks.
The 5G launch was originally planned for December 5 but this was pushed to January 5 to allow airlines and the FAA more time to address concerns. Airlines for America petitioned for a further delay and telecommunications carriers had previously offered to voluntarily delay nationwide 5G deployment by two weeks and restrict their own antenna operations in areas close to key airports where interference could lead to the most problematic disruptions.
The announcement on January 18 delays the launch only at a small number of locations close to some airports in a bid to reduce potential impacts on air traffic.
In a statement issued on January 18, President Biden thanked Verizon and AT&T for agreeing to delay 5G deployment around key airports and to continue working with the Department of Transportation on safe 5G deployment at this limited set of locations. “This agreement will avoid potentially devastating disruptions to passenger travel, cargo operations, and our economic recovery, while allowing more than 90 percent of wireless tower deployment to occur as scheduled,” the President said.
But 5G is coming and the FAA is working with airlines and manufacturers to assess how radar altimeters will perform in the 5G C-band environment. As tests prove that some altimeters are safe, the FAA will be able to remove some restrictions on operations of aircraft with those altimeters. Disruption risk will gradually decrease as more altimeters are tested and either deemed safe, retrofitted or replaced.
On January 7, the FAA disclosed the 50 U.S. airports that will have 5G buffer zones, including some of the largest hubs in the country. Then, on January 13, the FAA issued more than one thousand notices detailing the extent of potential impact of 5G services.
Airports Council International – North America (ACI-NA), the trade association representing commercial service airports in the United States and Canada, wrote to the FAA and the Federal Communications Commission (FCC) requesting a delay in 5G implementation to avoid widespread disruption across the U.S air transportation system.
“As a result of the Notices to Air Missions (NOTAMs) the Federal Aviation Administration (FAA) issued last night, more than 100 airports and heliports within 46 of the largest metropolitan areas of the country will have their low visibility approach procedures closed due to potential radio frequency interference between 5G transmissions and radar altimeters,” said ACI-NA President and CEO Kevin M. Burke in a January 14 letter to FAA Administrator Steve Dickson and FCC Chairwoman Jessica Rosenworcel.
“The airports affected include many of the largest and busiest commercial service airports in the United States, including airports in Boston, New York, Orlando, Dallas Fort Worth, Seattle, San Francisco, and Los Angeles just to name a few. More alarmingly, multiple Level I and II trauma hospitals will also see their low visibility approach procedures shuttered,” Burke said. “Despite promises from an eleventh-hour ‘deal’ made between the FAA and telecommunications companies, we still find ourselves facing the loss of this capability at hundreds of U.S. airports without any clear indication when it will be restored.”
Following the letter, the FAA released a notice on 5G and airworthiness. This time relating to Boeing 787 aircraft only. In line with the notice, operators of the planes will be required to take additional precautions when landing on wet or snowy runways at airports where 5G C-band service is deployed.
“Safety experts determined that 5G interference with the aircraft’s radio altimeter could prevent engine and braking systems from transitioning to landing mode, which could prevent an aircraft from stopping on the runway,” the FAA stated.
The Boeing 787 directive alone affects 137 aircraft in the United States and 1,010 worldwide.
Executives at Boeing and Airbus have warned that the technology could have “an enormous negative impact on the aviation industry.”
On January 16, the FAA cleared an estimated 45 percent of the U.S. commercial fleet to perform low-visibility landings at many of the airports where 5G C-band will be deployed on January 19.
The agency approved two radio altimeter models that are installed in a wide variety of Boeing and Airbus planes. The airplane models approved include some Boeing 737, 747, 757, 767, MD-10/-11 and Airbus A310, A319, A320, A321, A330 and A350 models. FAA expects to issue more approvals in the coming days. This combination of aircraft and altimeter approval opens up runways at more airports across the U.S. Even with these new approvals, the FAA said flights at some airports may still be affected and that passengers should check with their airlines if weather is forecast at a destination where 5G interference is possible.
Of course, 5G is not specific to the United States alone and many other countries have already rolled out the service with no risks to aviation. In the U.K. for example, the Civil Aviation Authority said in December that “conversations with other national aviation authorities have established that there have been no confirmed instances where 5G interference has resulted in aircraft system malfunction or unexpected behavior.”
And in Australia, the Civil Aviation Safety Authority has been closely monitoring the issue and stated on January 7 that it has seen no evidence 5G transmissions are currently affecting aircraft in the country. One reason for this is that Australian 5G transmissions currently do not extend into the part of the spectrum worrying the U.S. aviation industry.
So just because the likes of the U.K., Australia, Japan, France and others have not witnessed issues of interference between 5G and airworthiness, does not mean the U.S. will be the same as many factors come into play.
As House Committee on Transportation and Infrastructure Chair Peter DeFazio said: “These other countries have far fewer major airports and much less aviation activity than the U.S. To make this comparison without recognizing the critical differences that exist between the U.S. and every other country that has deployed 5G technology is disingenuous, misleading, and displays a glaring disregard for the potential safety measures needed to protect the flying public.”
DeFazio also said that nearly every other country that has deployed 5G has imposed some level of restrictions on its use to protect against harmful interference with aircraft. “These include reducing the power levels of 5G transmissions, requiring more extensive exclusion zones at airports, ensuring 5G operates at a farther distance from the aviation frequency band or limiting the directional tilt of certain 5G broadband antennas, among other things. Unfortunately, none of these restrictions are required in the U.S. and the voluntary mitigations that are in place are only temporary,” DeFazio explained.
The FAA says that U.S. airspace is “the most complex in the world”, and that deployments of 5G technology in other countries often involve different conditions than those proposed for the U.S., such as those described by DeFazio.
President Biden said on January 18 that government “has been engaging non-stop with the wireless carriers, airlines, and aviation equipment manufacturers to chart a path forward for 5G deployment and aviation to safely co-exist.” At his direction, theses efforts will continue “until we close the remaining gap and reach a permanent, workable solution around these key airports”.
Aviation of course is already stretched and suffering under the strains of operating in a pandemic. With hindsight, would it have been prudent to iron out the 5G concerns much earlier in the day? The FAA response is that it, the aviation industry, telecommunications companies, and their regulators, have been discussing and weighing these interference concerns for years. Recent dialogue has helped to establish information sharing between aviation and telecommunications sectors and newly agreed measures to reduce the risk of disruption, but the FAA says these issues are ongoing and will not be resolved overnight.
This story was updated on January 19 to include the latest cooperation from AT&T and Verizon as well as President Biden’s statement.