The Ongoing Saga of 5G and US Aviation

The stuttering US deployment of 5G wireless telecommunications – more powerful than elsewhere in the world and using frequencies with less buffer from those used by commercial aircraft altimeters, has created consternation among airlines. Robert W. Moorman explores the issue, the current truce, and training implications.

One would have to live in the “deepest jungles of Peru” (to quote Paddington Bear) to not be aware of the planned but contentious US rollout of 5G (fifth generation) broadband wireless technology by the telecommunication industry. Airlines, pilot unions, safety organizations and others have raised concerns that 5G signals could interfere with aircraft avionics systems, particularly the radar altimeters found on commercial airliners, business aircraft and helicopters. The radar altimeter, which measures distance from the aircraft to the ground in real time, is linked with terrain avoidance and warning systems.

Modern aircraft use the radar altimeter to change “aircraft handling qualities and prepare systems, such as ground spoilers and thrust reversers for deployment prior to touchdown,” according to the US-based Air Line Pilots Association (ALPA), a major pilot’s union. “This is in addition to radio altimeter use for autoland and in Category (CAT) II/III and Required Navigation Performance (RNP) AR approaches.”

5G is up to 100 times faster than 4G, hence the telecoms’ interest to hasten implementation for business and consumer applications, among them training/education. 5G’s extremely low latency rate means data transfer in 1 millisecond instead of 200 milliseconds for 4G. More reliable, more flexible, more interactive, more immersive, more personalized – all desired trends in simulation-driven learning.

Both 5G and the radar altimeter operate within the C-Band, which ranges from 3.7-4.2 gigahertz (Ghz). Radar altimeters operate within 4.2-4.4 Ghz. AT&T and Verizon, which own most of the C-Band, operate within the 3.7-3.98 Ghz frequency range.

In February 2021, the US Federal Communications Commission (FCC) auctioned off the C-band for $81 billion.

Adding to the concern is that the power levels of 5G signals in the US are higher than anywhere else in the world where the signal has been deployed.

“We were not aware that the power of the antennas in the United States has been doubled compared to what’s going on elsewhere. We were not aware that the antenna themselves have been put into a vertical position rather than a slight slanting position,” Emirates President Tim Clark stated when suspending the airline’s flights into US airports. He called the US inaction “one of the most delinquent, utterly irresponsible” situations he’s seen in his aviation career.

With international airlines such as Emirates, Lufthansa and British Airways cancelling flights to the States, the players in the 5G drama began to take notice.

Rollout of 5G, initially scheduled for December 5, 2021, was delayed until January 19, 2022. In advance of the rollout, the FAA issued flight restrictions around certain airports to safeguard against potential interference with aircraft systems. The FAA published a list of 50 airports where 5G wireless buffer zones would be in place for six months to reduce the risk of interference with aircraft systems.

“Even with the temporary buffer around 50 airports, 5G deployment will increase the risk of disruption during low visibility,” including “flight cancellations, diverted flights and delays,” the FAA stated.

Buffer or exclusion zones have been implemented in France and proposed for Canada. In France, the height of a 5G antenna and the power of its signal determine how close it is allowed to a runway and the flight path of an aircraft, according to a technical note from France’s ANFR (L’Agence Nationale des Fréquences). Antennas around 17 major French airports are also required to be tilted away from flight paths to minimize the risk of interference.

The delayed 5G deployment around US airports is a temporary fix; a permanent solution to the issue still hasn’t been determined.

“While I wish it happened earlier, the good news is we now have everyone engaged, the FAA and DOT at the highest levels, the ... aircraft manufacturers, airlines and the telecoms,” said Scott Kirby, United CEO. “While we don’t have a final resolution quite yet, I’m confident we’ll get there.”

Less assuaged, AT&T spokesperson Megan Ketterer stated: “We are frustrated by the FAA’s inability to do what nearly 40 countries have done, which is to safely deploy 5G technology without disrupting aviation services, and we urge it do so in a timely manner.”

There are still frustrations for regional airlines that fly smaller planes. Faye Malarkey Black, President of the Regional Airline Association said, “Manufacturers for regional aircraft have submitted those same plans to the FAA. They have not heard word back.”

On January 20, the FAA issued new approvals that allow an estimated 78% of the US commercial fleet to perform low-visibility landings at 5G airports, including some regional jets.

Airplane models with one of the 13 cleared altimeters include all Boeing 717, 737, 747, 757, 767, 777, 787, MD-10/-11; all Airbus A300, A310, A319, A320, A330, A340, A350 and A380 models; and some Embraer 170 and 190 regional jets. Notably, Bombardier jets, which are frequently flown by regional carriers, haven’t yet been green-lighted.

In a statement, the FAA said the agency “is working diligently to determine which altimeters are reliable and accurate where 5G is deployed in the United States. We anticipate some altimeters will be too susceptible to 5G interference. To preserve safety, aircraft with those altimeters will be prohibited from performing low-visibility landings where 5G is deployed because the altimeter could provide inaccurate information.”

In Europe, 5G is business as usual in Europe. “The technical data received from EU manufacturers offers no conclusive evidence for immediate safety concerns at this time,” stated the European Union Aviation Safety Agency (EASA). “At this time, EASA is not aware of any in-service incidents caused by 5G interference.” However, European 5G services use the slower 3.4 to 3.8 GHz range of C-band spectrum, meaning there is a much larger buffer between the spectrum used by radar altimeters and 5G.

In the UK, the Civil Aviation Authority issued a safety notice last week that “there have been no confirmed instances where 5G interference has resulted in aircraft system malfunction or unexpected behavior.”

Raging Rhetoric

Airlines for America (A4A), a lobbying group representing North American airlines, declined to be interviewed for this article. Nevertheless, A4A issued a strongly worded and widely dispersed letter signed by the CEOs of several US passenger airlines and cargo carriers on how 5G should be deployed. “We are writing with urgency to request that 5G be implemented everywhere in the country except within the approximate two miles of airport runways at affected airports as defined by FAA… This will allow 5G to be deployed while avoiding harmful impacts on the aviation industry, traveling public, supply chain…”

The letter warned: “Immediate intervention is needed to avoid significant operational disruption to air passengers, shippers, supply chain and delivery of needed medical supplies. The harm that will result from deployment on January 19 is substantially worse than we originally anticipated… ”

The letter went on to request that the FAA identify those base stations closest to key airport runways that need to be addressed “to ensure safety and avoid disruption…”

Not long after the letter was sent to US Transportation Secretary Pete Buttigieg, FAA Administrator Stephen M. Dickson and others, AT&T and Verizon announced that they would delay deployment of 5G within two miles of certain airports.

President Joe Biden thanked Verizon and AT&T for agreeing to delay 5G deployment at key airports. “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,” Biden said.

CITA, the trade association representing the wireless communications industry, said 5G has not had adverse effects on aviation.

Why Now?

The aviation community has known about AT&T’s and Verizon’s planned 5G rollout in the US for over a year. So why have they waited until the 11th hour to voice their safety concerns over the technology?

CAT posed this question to David Silver, Vice President for Civil Aviation for the Aerospace Industries Association (AIA). “It is not something that cropped up at the 11th hour from the aviation industry’s perspective,” he said. “AIA and its members have tried to call attention to this issue for almost four years.” In 2018, Silver raised safety concerns over 5G deployment to the FCC.

In 2020, the Radio Technical Commission for Aeronautics (RTCA) published a paper on how 5G signals could interfere with cockpit systems.

“We asked the telecom companies to participate in the RTCA study,” said Silver. “They declined.”

Dr. Hassan Shahidi, President and CEO of the Flight Safety Foundation said FSF has been working with the RTCA and other stakeholders on the dilemma of rolling out 5G safely. The Foundation believes a reasonable solution on 5G deployment will be found. “We believe that aviation and 5G will co-exist safely,” said Shahidi. “5G is an important technology that needs to be implemented in the US. We want to make sure the rollout is done safely and that it doesn’t impact the aviation sector.”

He added: “We have called for collaboration and information sharing to develop mitigating factors” on 5G rollout in the US.

Among suggestions being considered to reduce possible interference is tilting the antennae of cell phone towers below the horizon so the 5G signals don’t interfere with arriving or departing aircraft. Reducing the power output of the cell phone towers is also being considered.

“I think these proposals show promise and provide a path forward,” said Shahidi. “But, at some point, there may need to be upgrades to older altimeters.”

The concerns raised over 5G rollout in the US voiced by varying interests in the aviation community will likely result in long-term solutions. But the over-the-top comments by some officials sounded like dialogue straight out of a disaster movie. And could be more hindrance than help.

Meantime, Available Training

5G training programs have yet to develop fully, but there are developments worth noting:

Delta Air Lines, in collaboration with AT&T Business, is providing its 19,000 flight attendants with 5G-capable iPhone 12s. The new technology will help the flight attendants better assess in-cabin inventory with the help of augmented reality (AR) technology in the iPhone 12 camera. All flight attendants will undergo immersive training, which will help them perform tasks from passenger assistance to safety checks. The iPhone 12 can access AT&T’s fast 5G network directly, without the need to connect to WiFi hotspots between flights, according to the telecom company.

Embry-Riddle Aeronautical University (ERAU) offers students, engineers mostly, an avionics course that discusses 5G generally, as it relates to radio altimeter issues in-flight, said Eduardo A. Rojas-Nastrucci, PhD, Associate Professor of Electrical and Computer Engineering. Rojas said ERAU does not offer a specific course on 5G, but could in the future.

In ERAU’s Capstone Airline Procedures course, taught in a CRJ simulator, 5G is covered directly as one of the possible causes of radio altimeter failure, as outlined in the checklist.

“Along with addressing what to do, the checklist notes other warning systems that will be affected (by altimeter failure caused by 5G or any other reason – such as TCAS, GPWS and wind shear detection and guidance),” said Ken Byrnes, Chairman of ERAU’s flight training department. “Students are taught to follow the CRJ checklist, which has us increase the actual landing distance, typically by 15 percent, and has us manually deploy the Flight Spoiler Lever to max upon touchdown.”

Cornell University (eCornell) is offering students a 5G Strategy Certificate. The familiarization course covers the transition in wireless communication from 4G to 5G. While not aviation specific, Cornell is offering four online interactive 5G-related courses, three core and one elective: Innovating with 5G, Launching 5G Applications, Building Your Market Advantage and the elective course.

There are practical, business-related reasons why Cornell is offering the course. Revenues from 5G technologies could exceed $230 billion by 2025, the Ivy League university estimates.

Qualcomm Technologies, which has developed many of the technologies that make 5G possible, offers several training courses: 3G to 5G: An Overview for Business Professionals; Fundamentals of Cellular Communication and 5G; 5G NR for Industrial IoT Technical Training; 5G NR Multi-Access Computing - Training and other courses.

Nokia Bell Labs offers the 5G Training and Certification Programs for business leaders, students and technology professionals. Programs include the 5G Certification Associate and 5G Certification Professional programs. The Professional course consists of a series of advanced domain-specific certifications covering 5G strategy and planning. Nokia is a Finnish telecommunications and consumer electronics company.

After 5G comes 6G. Which is expected to be 100 times faster and more reliable than its predecessor, with wider network coverage. In 2019, China rolled out 6G, but to what extent is unknown. For most of the world, 5G will remain the standard for broadband cellular networks for the next several years. 5G’s long-term benefit to the air transport sector is unknown, but generally positive. In the interim, the FAA and savvy engineers will find temporary fixes to ensure that airlines and others can get on with business.

Health Concerns Persist Over 5G

As if aircraft safety concerns over 5G deployment weren’t enough, health worries regarding the wireless broadband technology have re-emerged in the debate over use of the technology.

Years ago, scientists postulated how prolonged use of cell phones exposes users to excessive amounts of radio frequency radiation (RFR). Which, they said, could cause brain and other cancers. The rollout of 5G brought the debate back to center stage.

The telecom industry faults concerned scientists for appealing to people’s fears and rushing to judgment.

Meanwhile, the FCC continues to maintain that 5G does not pose any health risks to cell phone users and sees no reason to change the 1996 exposure limits. Which are based mainly on research from the 1980s.

Scientists have called for additional study that involves 5G signals, which use millimeter waves “for the first time, in addition to microwaves that have been in use for older cellular technologies, 2G through 4G,” according to Scientific American.

The Bioinitiative Report, first issued in 2012, and updated each year between 2014-2019, deals with the relationship between the electromagnetic fields between power lines and wireless devices and health. The report concluded “that a reasonable suspicion of risk exists based on clear evidence of bioeffects at environmentally relevant levels, which, with prolonged exposures, may reasonably be presumed to result in health impacts.”

The Journal of Exposure Science & Environmental Epidemiology offered a counter view, in a review of studies published in March 2021. Thirty-one epidemiological studies were included in the review that investigated exposure to radar, which used frequencies above 6 Ghz, similar to 5G. The journal concluded: “The studies showed little evidence of health effects including cancer at different sites, effects on reproduction and other diseases. This review showed no confirmed evidence that low-level RF fields above 6 GHZ, such as those used by the 5G network, are hazardous to human health.”

Military Monitoring 5G

Like its civilian counterparts, the US Defense Department is also concerned about 5G deployment in the US on aircraft. Below are responses to questions which CAT posed to the Office of the Secretary of Defense. DoD Spokesman Russ Goemaere provided the answers.

CAT: Is the US military concerned about the pending rollout of 5G? If so, what are your specific concerns, as it relates to aircraft?

DoD: The DoD continues to work very closely with our FAA counterparts on this issue. All DoD Services issued bulletins to the field/fleet, making aircrews aware of the potential for interference and establishing a mechanism to report instances of interference. FAA NOTAMs for civil airfield also apply to military aircraft. The DoD has not issued any NOTAMS on instrument landings at military bases in 5G deployment areas.

CAT: Is the US military switching from 4G to 5G?

DoD: It is a Congressional mandate and DoD’s strategy to accelerate the adoption of 5G and NextG technologies due to the improved security and increased capabilities (capacity, volume, and latency) provided. In many military use cases, this entails adoption of new wireless connectivity and features, not just a transition from one generation (4G) to the next (5G). Therefore, the DoD switch from 4G to 5G and NextG is more than a mere transition of user equipment (handsets) and the supporting infrastructure.

CAT: Are aircraft-related personnel, pilots, air traffic controllers, and aircraft maintenance technicians being trained/educated on the benefits and concerns around 5G?

DoD: The DoD and FAA take safety of flight issues seriously and have worked closely to keep service safety organizations apprised of FAA advisories, directives, and policies with regard to 5G implementation within national airspace. All DoD Services issued bulletins to the field/fleet, making aircrews aware of the potential for interference and establishing a mechanism to report instances of interference.

CAT: Are NORAD and US Space Command switching to 5G?

DoD: The Office of the Under Secretary of Defense for Research and Engineering (OUSD(R&E)) is working with all Services and major Commands on the introduction and adoption of 5G technologies. Each represent specific requirements and technology adoption roadmaps.