# Infrastructure Past, Present, and Future Casebook/Air Traffic Control System
## Introduction

This WikiBook is a case study on the Air Traffic Control System written by Marshall Petit, Roberto Polverino, and Zach Dietz for the Infrastructure: Past, Present, and Future GOVT 490-007/CEIE 499-001 Spring 2022 course at George Mason University's Schar School of Policy and Government and the Volgenau School of Engineering Sid and Reva Dewberry Department of Civil, Environmental, and Infrastructure Engineering.
Before we start it's important to know what Air Traffic Control is and its role in flight transportation. Air traffic control includes equipment and ground-based personnel that monitor and control air traffic in specific areas. There are three sections that air traffic control can be split into including: tower control, approach and departure, and en route control.
With the number of air passengers expected to double in the next 20 years, according to the International Air Transportation Association [7], air traffic control will have to continue evolving and adapt to the increasing amount of flight passengers and the changing environment around Air Traffic Control infrastructure. This being infrastructure that may be vulnerable to the different technology and conditions the world is experiencing, much like what is being seen with the 5g rollout and the compatibility issues that may hold.
DISCLAIMER: The information presented in this wikibook is for academic purposes only and has no particular goal beyond presenting what has been learned. Any views presented in this wikibook are the views of their respective writers and do not necessarily reflect the views of our professor, Dr. Gifford, or that of our institution, George Mason University.

## Summary

Air Traffic Control (ATC) is a critical portion of aerospace infrastructure that manages the logistics and safety of air travel in a nation’s airspace. In the United States, the ATC system is operated by a government agency called the Federal Aviation Administration (FAA) that works within the Department of Transportation (DOT). The act of improving and managing air travel was a concept that members of the aerospace community knew needed to be addressed as early as World War I. The federal government took responsibility for regulating US airspace in 1926 with the Air Commerce Act and created the first organization to manage ATC in the US, the Civil Aeronautics Authority (CAA), in 1938.
ATC is most commonly recognized as a safety measure for air travel, but it also organizes the airspace of a nation and allows aircraft to safely travel along established pathways, or routes, across an open environment. The current method of organization, along with the tools and strategies it utilizes, has been a stable part of air transportation for about 80 years. It has, however, offered stability that has given its users the ability to maintain its operation and efficiency without the need to evaluate and/or upgrade major portions of its system often. Technological advancement is an issue the FAA faces on two different accounts. First, growing technology in other industries, such as 5G communications, can affect the technology used in ATC. Second, after many years of relying on the same systems since WWII, the need to update the FAA’s own technology to create a safer and more efficient method of organizing air travel has become a cumbersome and costly task that needs to be carried out quickly, but also carefully to recognize the effects that implementation and the new technology have on American communities and the aerospace industry. There are also critics who push to not only overhaul the current system, but to also take responsibility and management out of the federal government’s hands and privatize ATC.

## Actors

Public Sector:
* The Federal Aviation Administration (FAA): A sub-agency of the United States Department of Transportation; it manages the regulation of US airspace.
* The Air Traffic Organization (ATO): A branch division of the FAA directly charged with managing the operation of ATC.
* The US Department of Transportation (DOT): The cabinet department of the federal government that the FAA and ATO operate within.
* Airport Authorities: The groups, individuals, and organizations charged with maintaining the operation of their respective airports across the country. The executives are usually appointed by local government officials.
Private Sector:
* Airline Corporations: The primary providers of commercial air transportation across the world. While there are four major companies in the United States (United, Delta, Southwest, and American), there are smaller American businesses as well as international airlines that carry passengers and goods through US Airspace.

## Timeline

Wright Brothers (December 17th, 1903)
The first powered flight from the Wright Brothers proved that airplanes could be made and work, but it would not be until 1927 when planes could be used to carry passengers commercially.
World War 1 (1914 – 1918)
Trench Warfare in WW1 made reconnaissance difficult, and aviation was the only means of informing allies of enemy whereabouts and plans beyond their trench lines. The use of reconnaissance aviation in WW1 actually sped the development process of planes and aviation technology. People also started to understand the importance of controlling aircraft and how there was a necessity in directing planes so that crashes could be avoided. Cars are a great comparison to what went on with aviation during this time. When automobile technology was first being used there was no means of trying to control and manage traffic in any way until the use of cars became more common.
Transcontinental airmail service (1920)
The transcontinental airmail service was established in 1920. Mail was being flown across the country which expanded aviation to other practical uses that benefit people’s everyday lives. Flight was not possible during the night at this stage and mail had to be placed on trains that then finished off the mailing route. Nighttime travel was then tested on February 22, 1921 when the U.S. Postal Service attempted an experiment to fly mail out at night using bonfires to guide the planes. This experiment consisted of multiple planes, with one that crashed soon after take off resulting in the death of the pilot. This leads us to our first form of air traffic control infrastructure being rotating beacons that ended up replacing the use of bonfires.
Air Commerce Act of 1926
Federal involvement began with the Air Commerce Act of 1926 due to the recognition of increased air traffic and the need of having standards set in order to make flight safer and more controlled. The Air Commerce Act consisted of regulations that involved aircraft inspections, air traffic rules, aircraft requiring certification, and pilots requiring licenses. Airways and navigation aids also came from the Air Commerce Act of 1926.
Civil Aeronautics Authority (1938)
In 1938, Congress created the Civil Aeronautics Authority (CAA), which centralized regulation and execution of air traffic control. This was responsible for concentrating all regulation coming from the federal government into a single agency.
Radar technology (1952)
Radar technology was a primary tool in most flights involving arrival and departure by this time. This was seen as a revolutionary form of technology for air traffic control. The way it worked was through transmission involving beams of radio waves that are electromagnetic. These beams are sent out and reflected by objects. The receiver accepts the energy from the radio waves that return and the time elapsed since that initial transmission began is measured.
Federal Aviation Act (1958)
This created what is today known as the Federal Aviation Administration but back then called the Federal Aviation Agency. This allowed the agency to control and oversee safety in aviation for the industry both on the military and civilian side for the United States.
Contract ATC Towers are Introduced (1982)
In 1981, over 12,000 members of a union called the Professional Air Traffic Controllers Organization (PATCO) began a nationwide strike in retaliation to the FAA. The two parties had failed to reach a collective bargaining agreement that met PATCO’s demands, such as pay raises and reduced work hours, and acknowledged their concerns about the pressure associated with their work. President Ronald Reagan subsequently fired every member of the ATC union that continued to participate after being ordered to return to work in an effort to show that the federal government would not tolerate a strike. The mass release of the FAA’s workforce left the agency with significantly fewer employees and in need of labor from a new source. In 1982, the FAA began a new program to help alleviate its labor issue. The agency transferred its own employees out of ATC towers that regulated very little airspace activity and began hiring contract workers to manage everyday operations in an effort to allocate resources. This policy continues to be carried out by the FAA Contract Tower Program (FCT).
Workforce (Today)
Controllers are on duty for 24hrs and work at more than 350 locations spread out across the United States. There is no room for mistakes in this job since people's lives are in controllers hands. The strain, both mental and physical, is high and new air traffic controllers being hired cannot be older than 31 and are required to retire by the age 56. The FAA hires these controllers directly and once hired they attend training that lasts multiple years. These controllers learn a wide array of skill sets including: communication, equipment functionality, team work, and weather phenomena.

## Delivery and Technology

The Federal Aviation Administration runs the ATC network through 22 Air Route Traffic Control Centers (ARTCC) across the United States that handle their own respective region. They are generally headquartered in major cities that are located near the coast (Los Angeles, Oakland), are the biggest metropolises in their given regions (Houston, Chicago), are major travel hub centers through airports (Albuquerque, Cleveland), and/or are near a major military installation (Ft. Worth, Jacksonville).
Radar
The radar dish sends out radio waves, which bounce off of objects back to the radar dish, creating “images” of objects and/or weather phenomena in the air. Different radar dishes operate at different frequencies, or “bands”, allowing them to travel at different distances with different degrees of accuracy; the longer the distance, the lower the accuracy. Ex: E-band is long range, K-band is short range. E-band could be used to detect high-altitude aircraft, while K-band could be used to view the location of aircraft and vehicles near the runway during poor weather conditions. Multiple radar bands are used simultaneously to get a full idea of air traffic conditions.
Radio
ATC centers and pilots use two-way radios to contact one another. A two-way radio is a radio that can both send and receive transmissions.
In order to communicate by radio
* Both radios must be on the same channel
* Both radios must be on the same frequency
* Both radios must be on the same of either plain text or cipher text
** Plain text is unencrypted, meaning the data being transmitted is unchanged
** Ciphertext is encrypted, meaning the data is scrambled.
*** If using ciphertext, each radio must be loaded with the same encryption key, otherwise they will be unable to unscramble communications.
* Line of sight between radios must be achieved. This can either be direct line of sight, where the ATC operator’s and pilot’s radios can directly see one another, or through a “webbed” line of sight, where communications bounce from radio to radio until they reach their destination. The latter could be required during adverse weather conditions, such as when a stormcloud blocks direct line of sight between an ATC tower and a plane.
Most radios will be of the analog variety, or the typical radio you would imagine since World War II. The further the signal goes, the less clear it is, and only one person can communicate on any given frequency at a time. At the same time, these radios are easy to use, reliable, and cheap to manufacture. Newer radios are digital radios, which change your voice into binary (the computer language of 1s and 0s). Binary is simpler than audio data, and as such can be transmitted over further distances more efficiently and with less loss. As such, digital radios tend to have clearer audio. Digital radios are a newer technology, so they are not as widespread. They are also much more expensive than analog radios, and the extra cost is often not worth the increased benefits when analog radios are still capable of doing the job well.

## Finances of Air Traffic Control

As with most divisions of the federal government, the FAA’s annual budget is requested by the Presidency as part of the Department of Transportation’s overall budget and determined and allocated by Congress. The budget process is an intricate and cumbersome procedure that begins with the President sending a detailed budget request to Congress by the first Monday February. Congress then sends the request to budget committees in the House and the Senate, who create a resolution that sets amounts for mandatory and discretionary spending and must be passed with a majority vote by April 15th. Once passed, Congress will send the resolution to be reviewed by each chambers’ appropriation committees, who will each then send the resolution to twelve subcommittees, each overseeing the budget for a particular agency and/or field of government. These subcommittees will debate amongst themselves and consult experts and agency officials to determine how much spending will be allocated to each agency of the government and what it will be used for. The subcommittees then write their decisions into appropriations bills for the chambers to vote on. All appropriations bills must be passed by the start of the federal fiscal year on October 1st or the government will shut down.
In the 2021 fiscal year, the FAA has been granted a total budget of nearly $18 billion, about $14.6 billion of which is regarded as discretionary funds, meaning the FAA can choose what to dedicate most of its money towards (DOT, page Budget Summary Tables 2). More than $8.2 billion has been dedicated to operations of the Air Traffic Organization, roughly $5.9 billion covering salaries and expenses while more than $2.3 billion will pay for actual program costs (DOT, page Operations- Air Traffic Organization 1). Roughly $993 million is dedicated towards the implementation of NextGen, with roughly $794 million funding the facilities and equipment costs, such as weather programs, implementation portfolios, and new systems for unmanned aircraft (DOT, page Budget Summary Tables 12).

## Lessons

A common theme throughout this retrospective look at air traffic control is the evolution of flight technology due to tragic mistakes that resulted from carelessness or inadequate resources. One of these examples was the collision of two planes over the grand canyon in 1956 which resulted in 128 casualties. Policy acts accordingly in response to any outrage or feedback on an event, and sadly it takes a tragic incident in order for progress to be made for many cases. Because of the incident that occurred over the grand canyon, the government responded by implementing the Federal Aviation Act of 1958 which allowed for the Federal Aviation Agency to take full, consolidated responsibility over both the military and civil air and traffic control system. Congress also used roughly $250 million to fund the improvement of radar technology because of that incident. This tragic event that occurred over the grand canyon in many ways initiated the death of flying’s freedom. What is meant by this is that the rise of mid-air collisions paved the way for a more interconnected system that used radar and communication technology to have control over the skies and not just treat it like an open area where anyone can occupy the space. The problem with the old system was that it lacked control and surveillance. The air traffic control system we have today makes sure that the skies are watched and controlled using this interconnected and complex network.
After seeing the change in air traffic control over the U.S, it is important to also recognize that evolving isn't always the correct step forward and sometimes the situation calls for other ways of dealing with a problem. Much like the complicated situation that's being seen with 5G rollout and the issues with the existing equipment.

## 5G Rollout

5G is a standard that is now replacing the familiar 4G for mobile communication and surfing the web. 5G would be the latest and fastest version, but is catching some attention for possible problems it could cause. The Federal Aviation Administration has recently come out and addressed the potential problems 5G could cause for some of the automated features pilots use when either flying the plane or landing. Wireless towers are the source of this problem since any of the towers nearby transmit these 5G signals.
The automated systems in the cockpit are extremely important for plane travel. The prevention of collisions on air and ground as well as landing in hazardous weather conditions are primary uses of this technology. Another piece of technology that is being considered in potential threats from 5G signals are radar altimeters, which are instruments that measure the distance between the ground and the aircraft above.
3.7 - 4.2 GHz is the frequency range of concern. This is optimal for 5G usage. Aviation Equipment functions under a frequency range of 4.2 - 4.4 GHz which makes for an increased chance of interference.
The problem with this issue is 5G offers a very substantial speed increase from its 4G predecessor. A delay in 5G affects the competitiveness for America in innovation and advancement. This is especially important for industries that use the high speed communication/internet capabilities and the telecom business that manages these capabilities.
Airlines such as United, are stressing their concerns to the Biden Administration here in the U.S and emphasizing the fact that other countries have taken more time into dealing with 5G rollout and implementing new policies to resolve the issue. In early December both AT & T and Verizon had planned to rollout the 5G but delayed it two different times.
So far the FAA (Federal Aviation Administration) is working with government officials to plan out a solution, one that will allow both of these things to coexist since both are indeed crucial. New statements are posted on the FAA website along with their publication dates with the most recent having been released late February. This statement addressed revisions that are being done to landing requirements for specific Boeing 737 series planes landing at airports where 5G interference could potentially occur.

## Privatization

Privatizing ATC has been an ongoing discussion to deregulate air travel and save money within the federal government. The discussion of privatization has recently been addressed in 2017. The House Transportation and Infrastructure Committee reviewed the 21st Century AIRR Act, written by Chairman Bill Shuster (R-PA) and committee member Frank LoBiondo (R-NJ), that would give a private corporate board control, management, and financial responsibilities of ATC in the United States. This would allow the board to charge for service and the decisive power to allocate funds to initiatives and facilities of their choice.
If control of ATC was taken away from the FAA, the few American-based airline companies left could have a greater say in destinations and air travel overall by choosing where to fund ATC facilities and which initiatives to support. This could affect the economic outlooks of cities that are not chosen by major companies or the airline corporations to receive funding, putting the tourism industries and accessibility of cities at risk.
The bill was passed out of committee, but privatization of ATC remained as an invigorated topic of discussion within the aerospace community. There are several countries that use a privatized ATC system, most notably Canada, which uses a non-profit corporation created by the government in 1996 called Nav Canada. While the corporation has offered a stable, hands-off alternative to the national government running ATC, it is also a smaller organization that manages airspace for a country not as vigorously traveled as the United States. Nav Canada employs 4,000 workers that operate in 100 facilities and it manages 18 million square kilometers of airspace, or less than 7 million square miles. The FAA’s workforce consists of roughly 14,000 employees working in 350 facilities that collectively regulate about 26,400,000 square miles of airspace. If the federal government decides to put responsibility of ATC in possession of the private sector, it should expect a slow transition and a need to assist in the creation of a more robust organization to handle this vital work for a growing industry in a capacity that would exceed the peak of the FAA's involvement.

## Implementation of NextGen

Technology, however advanced, durable, and useful, will eventually become outdated and need to be replaced, and the FAA is facing that reality with its ATC technology. ATC is currently managed through a radar system developed during World War II which, while more than serviceable in its roughly 80 years of use, is limited in its ability to create direct air routes safely and efficiently. The FAA intends to overhaul this system by replacing it with its multi-billion dollar NextGen initiative, which utilizes satellite-based navigation. This will not only allow for more direct flights, but will also give the FAA the capacity to monitor more flights at a single time and will help them to mitigate the environmental impact of air travel.
NextGen was first initiated in 2003 when Congress passed the Vision 100- Century of Aviation Reauthorization Act. The FAA, however, has experienced many delays in implementing the new system. New forms of equipment and software are needed on aircraft, in ATC towers, and in airports. The FAA also needs to train and/or hire the employees, pilots, and airport staff that will be part of using this modern program. The agency also needs to reevaluate its facilities, its users, and airports across the country to determine what changes in procedures need to be made to accommodate the new program, such as take-off and landing and in-flight navigation. All aspects of this revaluation may need to be resolved on a case-by-case basis. The deadline to fully implement NextGen was originally set for 2025, but the Coronavirus pandemic forced the agency to temporarily place integration lower on its priorities list, and speculation from within the FAA as early as 2013 stated the project was about ten years behind schedule.
While the initiative will allow for a faster, more fuel efficient industry when fully implemented, changing air routes that have been in place for decades will also cause changes in other areas of life. Communities across the country have begun to experience louder noise from flights due to redirected routes. The increase in noise pollution has been called on to be addressed by the House Committee on Transportation and Infrastructure with several of its members claiming the FAA did not seek input from communities that would experience flight rerouting or an environmental review that addressed these changes. The FAA, in response, intends to set up a complaint program online to take in new information to mitigate noise pollution and adjust flight patterns.
The ultimate goal of NextGen is not just to create faster, safer, and more efficient air travel, but to restructure the organized environment of airspace and the methods the FAA uses to control it. Unfortunately, airspace is not the only part of the US that will see changes as implementation continues. Just like renovating another capital investment/project, NextGen will noticeably affect surrounding areas as it is implemented and will alter the businesses and quality of life for communities around airports. While it is still necessary to upgrade the ATC system to satellite-based navigation, especially as other nations begin to move toward their own implementation, it will be vital for the FAA to recognize the effects of its work outside of its facilities.

## Discussion Questions

* Is the United States spending the appropriate amount of money on ATC and the FAA at large? If not, how much should be spent and towards what policies/capital/initiatives?
* How should the FAA approach the issue of 5G rollout and future issues that could emerge from technological advancements in the private sector? Should there be collaboration between the government and communication companies to resolve the current issue? If so, how much?
* How concerned should the FAA be when communities report increased noise pollution due to new air routes created by satellite navigation? What do you think it can do to help mitigate this and other effects of its changing system?
* What other issues could arise from the implementation of the NextGen program?
* Did the FAA and the federal government wait the appropriate amount of time before addressing the need to update its ATC system? If not, when should they have first addressed the issue?
* Should the responsibility of ATC be taken away from the federal government and privatized? If so, should a non-profit corporation be created to run it or should it be managed by a commission of airline companies? Why do you think?
* If privatizing ATC is not feasible but the federal government is not offering a satisfactory service, what should be done?
* What do you believe will be the next issue the federal government and the FAA will face towards the operation of ATC?

## References

1) What is Air Traffic Control? (2018). Sofia Tokar. https://www.snhu.edu/about-us/newsroom/stem/what-is-air-traffic-control
2) Echoes in the Grand Canyon: Public Catastrophes and Technologies of Control in American Aviation. (2007). Taylor & Francis. https://www.tandfonline.com/doi/abs/10.1080/0734151042000202045
3) How Do Radars Work? (2021, October 13). Lockheed Martin. https://www.lockheedmartin.com/en-us/news/features/2021/how-do-radars-work.html#:%7E:text=%20How%20Do%20Radars%20Work%3F%20%201%20Step,measures%20the%20time%20elapsed%20since%20the. . .%20More%20
4) Butts, T. (2022, January 18). U.S. Airlines Issue Dire Warning Over This Week’s 5G Rollout. TVTechnology. https://www.tvtechnology.com/news/us-airlines-issue-dire-warning-over-this-weeks-5g-rollout
5) Tangel, A., & Ryan, T. (2021, Oct 30). FAA Plans Warnings to Pilots, Airlines Over New 5G Rollout. Wall Street Journal https://www.proquest.com/docview/2588203846
6) Access Denied. (2022). FAA. https://www.faa.gov/newsroom/faa-statements-5g
7) 2036 Forecast Reveals Air Passengers Will Nearly Double to 7.8 Billion. (2017, October 24). IATA. https://www.iata.org/en/pressroom/pr/2017-10-24-01/
8) National Air Traffic Controllers Association. (2022, April 15). Home. NATCA. https://www.natca.org/
Link to pdf going through the history of ATC from same website: https://www.natca.org/wp-content/uploads/2019/12/NATCA_ATC_History.pdf
9)The House Committee on Transportation and Infrastructure. (n.d.). Air Traffic Control Privatization. The House Committee on Transportation and Infrastructure. https://transportation.house.gov/committee-activity/air-traffic-control-privatization
10) Nav Canada. (n.d.). About Us. Nav Canada. https://www.navcanada.ca/en/corporate/about-us.aspx https://www.navcanada.ca/en/corporate/about-us.aspx
11) Federal Aviation Administration. (2022, March 18). Air Traffic by the Numbers. Federal Aviation Administration. https://www.faa.gov/air_traffic/by_the_numbers/
12) US Department of Transportation, BUDGET ESTIMATES FISCAL YEAR 2022 (2022). US Department of Transportation. https://www.faa.gov/about/budget
Link to pdf going through the budget proposal of the FAA in 2022 from same website: https://www.transportation.gov/sites/dot.gov/files/2021-05/FAA-FY-2022-Congressional-Justification.pdf</nowiki>
13) Policy basics: Introduction to the federal budget process. Center on Budget and Policy Priorities. (2020, April 2). https://www.cbpp.org/research/introduction-to-the-federal-budget-process
14) This is NextGen. Federal Aviation Administration. (2022, January 5). https://www.faa.gov/nextgen/this_is_nextgen/
15)NextGen. Federal Aviation Administration. (2022, March 8). https://www.faa.gov/nextgen/
16) Jackson, W. (2013, July 22). What's keeping FAA's NextGen Air Traffic Control on the runway? GCN. https://gcn.com/data-analytics/2013/07/whats-keeping-faas-nextgen-air-traffic-control-on-the-runway/281800/
17) Aratani, L. (2022, March 17). Lawmakers examine FAA response to aviation noise, say more public outreach is needed. The Washington Post. https://www.washingtonpost.com/transportation/2022/03/17/congress-airplane-noise-airports/
18) FAA Contract Tower Program. Federal Aviation Administration. (n.d.). https://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/mission_support/faa_contract_tower_program
19) Barera, M. (2021, September 2). The 1981 PATCO Strike. University of Texas at Arlington Libraries. https://libraries.uta.edu/news-events/blog/1981-patco-strike#:~:text=Forty%20years%20ago%2C%20in%20August,Administration%20(FAA)%20broke%20down
20) Digital vs. Analog Radios: What you need to know. TwoWayRadioGear. (n.d.). https://twowayradiogear.com/blogs/news/digital-vs-analog-radios-what-you-need-to-know
21) Kern, R. M., By, & -. (2020, January 1). Air Route Traffic Control. AVweb. https://www.avweb.com/flight-safety/faa-regs/air-route-traffic-control/
All images were used from WikiMedia Commons