Update, January 19: On the evening of January 18, 2022, information about the safety impacts of the 5G rollout finally hit aviation operators. The most affected aircraft is the workhorse of international travel, the B777.
In the midnight hour, before the rollout on January 19, the Federal Aviation Administration (FAA) issued a temporary fix — an addendum to its recent Airworthiness Directives (AD) — to allow certain aircraft to fly into the 50 selected airports, called an Alternative Method of Compliance (AMOC).
Flight crews are scrambling to read the new rules and instructions regarding what to do when there is interference with the radio altimeter, the important navigation system that may be affected.
AT&T and Verizon have agreed to delay flipping the switch to full power at the 50 designated airports. However, the guidance from the FAA about the AD’s will remain active.
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I sat patiently listening to the flight attendant giving instructions on how to access the Wi-Fi system on the jet while sitting in seat 21A. I gazed down at my iPhone 7+, traveling to my next flying assignment, and thought to myself, “My phone is old, very old, like 5 years old.” I contemplated whether my old iPhone 7+ is going to work on this new 5G system that is about to roll out, or if I need to plunk down a grand on a new phone…
What Is 5G?
5G is the fifth generation telecommunication technology standard for broadband cellular networks. It is new, broad, fast, and replaces 4G broadband. 5G is so powerful it is designed to connect virtually everyone and everything together, including machines, objects, and devices at incredible speed. Initially planned to roll out December 5, 2021, but pushed back to January 5, 2022, due to a major roadblock, 5G is now scheduled for January 19, 2022.
So Who Is Blocking The Rollout Date?
Verizon and AT&T both agreed to delay their planned rollout date due to the FAA’s concern about potential interference with major aircraft cockpit safety systems. As in life, both sides have claimed that their position is true and that the other side is making nonsensical arguments. The Federal Aviation Administration’s (FAA) focus is always from a position of safety for the flying public. The telecom networks have invested billions of dollars into this new system and scoff at the concerns of the FAA. Policymakers are skeptical of the FAA’s data. Currently, they are trying to find a solution to coexist together safely.
Problem, What Problem?
As with any new technology, 5G comes new, unforeseen problems. The big fly in the ointment is the bandwidth of 5G. Current critical electronic systems on passenger aircraft and 5G bandwidths interfere (overlap) with each other. The Federal Communication Commission (FCC) says there isn’t any substantial proof of issues, yet the FAA and multiple pilot groups say there are considerable concerns for aircraft safety. Again, differences arise based on what agency you believe. Luckily, safety groups are acknowledging potential safety issues regarding aircraft and have implemented temporary roadblocks.
What Is A Bandwidth?
In this instance, it isn’t the size of your favorite rock band; it is the range of the cellular network’s radio frequencies that transmit data over a connection within a specific amount of time. 5G is going to come in basically three bandwidths: A, B, and C. Each does something special but allows people to transmit a lot of data lickety-split. Bandwidth is represented in the number of bits, kilobits, megabits, or gigabits that can be transmitted in 1 second. The 4G bandwidth has run its course and is limited to operate in a much smaller bandwidth; hence, the amount of data that it can transmit is less.
Is There Going To Be A Battle?
The battle brewing between the aviation and the communication communities is based on the embedded interference within the range of the 5G bandwidth and a precision system on aircraft called the radio altimeter. The RA operates in a specific bandwidth of frequencies and hasn’t had to share its frequency with anyone. Along comes 5G, and the range the RA operates in lies right in the middle of the 5G spectrum. Let’s keep this simple. I visualize bandwidth like looking at a clothes rack. To the far left you have a section of clothes that starts at XS (extra small), then S (small), then M (medium), and on and on until you reach XL (extra large). 5G broadband uses the range between XS and L. RA’s in aircraft use a sliver of the range from Medium to Large. This “shared” frequency range creates interference. The major concern is what will this do to the information the radio altimeter is communicating to the aircraft.
What Is A Radio Altimeter?
The radio altimeter is one of the most critical components of aircraft operations. It is the only sensor on the aircraft that provides an absolute measure of the aircraft’s altitude over the ground. It operates below 2,500 feet above the ground. This system is most critical when it comes to many automated landing and collision avoidance systems. Any undetected failures of this system can lead to catastrophic results, and false alarms have the potential to undermine the trust in the avionics systems. The RA is critical when it comes to low-visibility landings. If the RA isn’t working, pilots can’t land in reduced visibility. In other words, when the fog rolls in like pea soup in San Francisco and the RA is unreliable, you won’t be landing there! In addition to low-visibility landings, the RA works with onboard computers and a laundry list of important systems such as ground proximity warnings, auto-land and flight control laws, auto-throttle/stall function, and many more. Each one is critically important to the operation of the flight.
What Is Going To Happen?
There is a bit of uncertainty about what is going to happen in the future with the rollout of 5G. At this time, the FAA is in a head-to-head battle with the current administration and the FCC. The position of the FAA is to protect the flying public with safety at the forefront. The FAA has initiated Airworthiness Directives for airliners and helicopters equipped with radio altimeters. (AD 2021-23-12 and AD 2021-23-13). In a nutshell, these ADs state that RAs using the bandwidth which is part of the 5G C-Band spectrum may have unreliable, missing, or erroneous indications. If there is a disturbance, the pilot might not recognize the interference in time to maintain and continue safe flight and/or a landing. At this time, pilots won’t have a warning that there is interference with an unreliable RA while flying.
So Now What?
Armed with this new information, the FAA has issued Notices to Air Missions (NOTAMS). This is a current bandaid to the system to notify pilots and operators of the potential problem areas. NOTAMS will now be issued where 5G wireless broadband networks in the C-Band are expected to begin on January 19, 2022, and are limited to approximately 50 predetermined areas. The temporary plan is to implement a system similar to how France is handling this problem. The selected towers will be downgraded to a lower wattage and angled lower in an attempt to mitigate the frequency interference for 6 months. Meanwhile, in the U.S., these NOTAMS will now greatly affect aircrafts’ ability to fly in low visibility and to land. The irony is that accidents over the last 50 years have inspired technology and instruments to aid in safer flight. These very systems are now handicapped when the weather visibility gets low. Two perfect examples are Boeing’s 787 and 737 MAX. Both will have their calculated landing distances increased if the runways are wet. Operators typically reduce their payload and passenger count to reduce the weight to allow the aircraft to stop with the newly calculated landing distance. The FAA’s new rules will result in flight cancellations and delays at major airports when the weather deteriorates. Pilots will expect to be notified by a NOTAM about specific airports within the presence of 5G C-Band interference that their RA is now unusable and dispatch is jeopardized. Most of the NOTAMS will state that SA CAT1, CAT 2, and CAT 3 approaches can not be executed. The mighty 777 will no longer be allowed to fly an auto-landing with only 300 feet of visibility. It will raise the visibility limits to a CAT 1, or 2400 feet.
Didn’t See This Coming?
The real-world ramifications of this will be major inconveniences for passengers, crews, and ground staff when the weather minimums get low. I see one of the greatest travesties may be to medical flights (Medivac) when it comes to transporting critical patients and live organ transplants.
What Does This Mean For You?
Until this problem is resolved, if you are flying on a commercial flight to a destination within the specified area within the U.S., depending on the weather, your flight might not get dispatched or may be delayed or canceled due to the FAA’s 5G C-Band restrictions. It will be very interesting to watch and see how these powerful agencies work together to mitigate this technological storm that is brewing.