Infrastructure Past, Present, and Future Casebook/Automatic Dependent Surveillance-Broadcast (ADS-B)

ADS-B System Communication

This casebook is a case study on Automatic Dependent Surveillance-Broadcast (ADS-B) by Vinny Gaskin and Ian Bednarek as part of the Infrastructure Past, Present and Future: GOVT 490-003 (Synthesis Seminar for Policy & Government) / CEIE 499-002 (Special Topics in Civil Engineering) Spring 2023 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. Modeled after the Shinkansen High Speed Rail Casebook. Under the instruction of Professor Jonathan Gifford.

Summary

Automatic Dependent Surveillance-Broadcast (ADS-B) is an advanced piece of technology that combines an aircraft's positioning source, aircraft avionics, and a ground infrastructure to create an accurate surveillance interface between the aircraft and air traffic control (ATC). ADS-B allows for air-to-air and air-to-ground communication, which enables a one-way contact between pilots and ATC, as well as pilot to pilot. ADS-B is a performance-based surveillance technology that is more precise than radar and consists of two different services: ADS-B Out and ADS-B In. ADS-B Out allows for aircrafts to relay information such as their identification, current altitude, positioning, and velocity, to other vehicles and air traffic control centers. ADS-B In provides aircraft with the ability to receive this information.

ADS-B is 'automatic' because it doesn't require input from any pilot or other external interrogation. It is 'dependent' because it relies on the accuracy of an aircraft's navigation system with factors of positioning and velocity data. The 'surveillance' of ADS-B is aircraft position, altitude, velocity, and other data that is provided to the facilities that require this data. Lastly, the 'broadcast' part of the name refers to the information being broadcasted, every half-second at 1090MHz, to be monitored appropriately by the designated ATC ground stations and other aircraft.

As of April 2023, ADS-B is required when flying in Class B and C airspaces in the United States. There are five different classes of airspaces in aviation, these classes are separated by their elevation and proximity to prominent airports. Class A airspaces refer to anywhere between 18,000 and 60,000 feet above sea level. Class B airspaces go from sea level to 10,000 feet high when in the vicinity of an airport with heavy traffic. Class C airspaces are similar to Class B, but they only extend from sea level to 4,000 feet above the surface when close to a busy airport. Class D airspaces surround less crowded, smaller airports from sea level to 2,500 feet above ground. Class E airspaces are controlled and are around federal airways or other important approach paths. A pilot would need prior permission from Air Traffic Control Towers before operating in Class A and B airspaces. In Class C and D airspaces they would need an established two-way communication with the Air Traffic Control Towers.

Timeline of Events

1990 - The Aircraft Owners and Pilots Association (AOPA) embraced "Global Positioning System" (GPS) technology.

March 2003 - A presentation of ADS-B's abilities was delivered to the Civil Air Patrol (CAP) by the AOPA. These demonstrations were done to inspire a possible integration of the technology into CAP activities.

2006 - Sweden began installing its nationwide ADS-B network using 12 ground stations. Finished installations in 2007.

2007 - The Federal Aviation Administration (FAA) started to implement ADS-B infrastructure and mandatory aircraft equipage.

December 2008 - The FAA administrator granted permission for the installation of the first fully functional ADS-B system in the United States. The installation happened at a location in southern Florida.

2009 - Canada joins other countries in the advancement of aviation technology by commissioning operational use of ADS-B to provide coverage of the areas that formerly lacked it.

May 2010 - The FAA published a rule that by January 1, 2020, all aircraft owners must equip their vehicles with ADS-B Out systems when flying in Class A, B, C airspaces and in Class E airspaces when flying higher than 2500 feet above ground level. This mandate became effective on August 2010.

June 2012 - Chevron Corporation and FreeFlight Systems were awarded a Supplemental Type Certificate (STC) by the FAA for equipping a Gulf of Mexico (GOMEX) helicopter with ADS-B. This is special as the Gulf of Mexico is a crowded area with intense traffic as thousands of flights taking place every day.

September/October 2019 - The FAA successfully reached its final milestone in ADS-B implementation. The final two airports, both located in Ohio, received ADS-B and became functional during September 2019. This was monumental as all airports were equipped with ADS-B and it became operation all across the country before the due date of January 1st, 2020 all while staying within budget.

April 2023/Present Day - In the United States, ADS-B is currently required in all aircrafts when flying over the 48 connected states when operating above Flight Level (FL) 100, or 10,000 feet above the ground. When flying at FL 100 or below this altitude ADS-B is still required only when operating in class B or C airspace, or when flying within 12 miles (nautical miles) of the coastline of the Gulf of Mexico while flying over 3000 feet above sea level. These requirements change for Alaska, Hawaii, Puerto Rico, and the other United States territories, as they have their own unique regulations.

Narrative

In 2012 a researcher made the claim that ADS-B technology had no defense mechanism against “spoofing” or the sending of faulty messages by identifying , this risk was due to the fact that ADS-B’s data was neither authenticated or encrypted. The lack of encryption throughout the messages delivered by ADS-B makes them able to be read by anybody, which poses a security risk.

The FAA responded to these concerns by stating that they were currently being dealt with but could not disclose the methods of how these issues were being dealt with as the methods they were employing were classified.

Aircraft that are equipped with only a transponder, or with no transponder at all will not appear on the radar of ADS-B. This means that pilots who become overconfident or over-reliant in the capabilities of ADS-B may not be able to identify aircraft that lack the technology to appear on their radars, which is a great safety to both pilots and aircraft involved.

Another system that is frequently used by aircrafts in the United States and other countries across the world is FLARM. FLARM is a combination of the words flight and alarm and is used on most glider aircraft, which poses a problem as FLARM technology is not compatible with ADS-B.

There was also controversy regarding the ADS-B mandate which required implementation of ADS-B on all aircraft by January 1, 2020. Many pilots were outraged as they were forced to equip their vehicles with technology as expensive as ADS-B is. Many pilots anticipated that the FAA would rescind the mandate in hopes that they would not be forced to outfit their own vehicles with ADS-B. This mandate made some pilots claim that ADS-B was an unnecessary addition that drive many casual pilots away from the aviation industry.

Key Organizations and Institutions

Key organizations and institutions involved with the development of ADS-B technology include:

Seal of the United States Federal Aviation Administration

Federal Aviation Administration (FAA):

Transportation agency in the United States that became a part of the Department of Transportation in 1967. The FAA regulates U.S. commercial space transportation, and all civil aviation within the United States and surrounding waters to promote safety. The FAA also develop and operate air traffic control and navigation systems for civil and military aircraft.

National Business Aviation Association (NBAA):

Leading organization for companies that rely on general aviation aircraft to help make their businesses more efficient, productive and successful. The NBAA supports efforts to modernize the United States' airspace, such as the equipage of satellite-based ADS-B capabilities for monitoring aircraft in the skies and on the ground.

American Owners and Pilots Association (AOPA):

The American Owners and Pilots Association, incorporated in 1939, is a not-for-profit organization that is dedicated to general aviation. The AOPA supports the concept of ADS-B and knows the importance of near-universal participation. However, the AOPA has contributed its input on the FAA's implementation strategy. The AOPA suggested different technical changes that can make the ADS-B systems more affordable, and has also suggested that aircraft should be allowed to remove their transponders due to the transitions from radar and transponders to ADS-B.

Cargo Airline Association (CAA):

The Cargo Airline Association, originally founded as the Air Freight Forwarders Association, is an organization that represents air freight forwarders (indirect air carriers) and five all-cargo airline members of the cargo industry. When word got out that the FAA may delay oceanic Air Traffic Control operations of space-based ADS-B by 6 to 7 years (from 2022 to 2028/2029), the CAA joined the interested aviation stakeholders in a letter to FAA Administrator, Steve Dickson. Contents of this letter presented the stakeholders' urge for the leadership to ensure that every necessary step to implement the space-based ADS-B in the United States oceanic airspace was taken, in order to meet the original start date as close as possible.

Embry-Riddle Aeronautical University (ERAU):

Embry-Riddle Aeronautical University is the world's largest, fully accredited university specializing in aviation and aerospace. In May of 2003 Embry-Riddle Aeronautical University began using ADS-B on its main two campuses, in Arizona and Florida, as safety reassurance. In 2006 ERAU became the first aircraft to combine ADS-B with a glass cockpit.

University of North Dakota:

The University of North Dakota is one of the most comprehensive aerospace universities in the world. In 2006 an aerospace researcher from the John D. Odegard School of Aerospace Sciences at UND received a $300,000 grant from the FAA to research ADS-B technology. The university's aircrafts have since been equipped with ADS-B packages.

Funding & Financing

It is difficult to pinpoint the exact cost on how expensive it is to install ADS-B in the present day, as there are many variables that go into this cost. Some of the variables that determine the price of ADS-B include, type of equipment being installed, the certification process, and the cost of labor that it would take to install it. A group of pilots from a 2019 thread claim that the cost that they paid to install ADS-B into their own aircrafts ranges anywhere from $1000 to $7000.

The lead funding agency for ADS-B is the FAA. ADS-B is purchased either in bulk by organizations such as the FAA or by individual pilots for their own personal usage.

In April 2011, an equipping fund for general aviation aircraft was permitted through US federal legislation via House Bill for FAA reauthorization

A 2016 article claims that to meet the FAA's requirements the minimum cost for ADS-B installation would cost pilots around $4000 to $6000 and more complex systems will be even more pricey.

In 2020, a Texas-based Aerospace company named FreeFlight Systems made the claim that they will deliver ADS-B systems that meet FAA requirements while costing no more than $2,000.

Garmin and other GPS-enabled technology companies currently have ADS-B and transponder systems for sale on their websites. The least expensive system that included both ADS-in and ADS-out came out to be around $2,500. This is a good estimate on how pricey a fully operational ADS-B system would be in today's market.

Institutional Arrangements

Exemption 12555: Navigation Accuracy Category for Position and Navigation Integrity Category Exemption

• "does not exempt the requirement for compliant ADS-B Out equipment to be installed and operational on aircraft flying in ADS-B rule airspace.
• does allow for the extended use of an older type of GPS navigation receiver already installed in some aircraft. All other ADS-B Out equipment requirements must still be met and operational.
• was granted because multi-frequency/multi-constellation GPS navigation receivers suitable for transport category aircraft that meet the ADS-B Out Rule requirements were not available for purchase or installation in sufficient quantities until closer to 2020.
• imposes certain conditions, limitations and additional pre-flight responsibilities on the operators."

ADS-B Support Pilot Program: FAA-proposed program that allows for airports to receive AIP grant money to supplement other FAA funding sources for ADS-B ground equipment.

May 2010 - the FAA issued a final rule prescribing equipage requirements and performance standards for ADS-B Out avionics on aircraft operating in certain airspace after January 1, 2020.

2019 - Operators were required to confirm that a planned route of flight would comply with the ADS-B performance requirements.

An ADS-B receiver

Lessons Learned/Takeaways

Ostrom's Infrastructure Performance Criteria:

Efficiency: ADS-B is an incredibly efficient piece of technology that has revolutionized the aviation industry for the better. ADS-B improves the flow of air traffic with more efficient spacing and optimized routing to get pilots to their destinations efficiently, no matter what environmental conditions are thrown their way. This optimized routing leads to shorter flight times which benefits the environment by reducing fuel usage and pollution as well as saving time for the pilots and passengers. ADS-B systems provide air traffic control with updated information on their whereabouts nearly every second, which is far more efficient than the average radar that updates every 5 to 12 seconds. These constant updates allow pilots to identify threats quickly and react accordingly which leads to increased safety during a flight. It is not a perfect system though as a lack of encryption and authentication can make it suspectable to being hacked quite easily by someone with bad intent.

Fiscal Equivalence: Installing ADS-B equipment can cost pilots anywhere from $1000 to $7000 depending on a few variables. There is a lot to consider when deciding if the installation of ADS-B is a fiscally equivalent process or not. It is a one-time purchase that brings great benefit to pilots and gives them access to most airspaces, but it may not be worth it for some pilots that do not fly often or only operate in unclassified airspaces.

Redistribution: ADS-B does not contribute in terms of redistributing wealth as it only affects a specific group of people. ADS-B only directly influences pilots and those who are wealthy enough to take flights frequently. The cost to install ADS-B can be quite a burden on pilots as well, this means casual aircraft fliers may be disadvantaged if they cannot afford to equip the technology required. Rather than taking from the rich and giving back to the poor, ADS-B seems to take from the middle-class citizens and give it back to the rich. In less general terms ADS-B, specifically the 2020 mandate, benefitted the FAA and ATC and it was a detriment to individual pilots.

Accountability: When potential security risks were brought up to the FAA, they responded to these concerns by stating that they were currently being dealt with but could not disclose the methods of how these issues were being dealt with as the methods they were employing were classified. This shows questionable accountability because if the public does not know how you are dealing with these security issues there is no way to know that they are being dealt with at all.

Adaptability: ADS-B is still relatively new, so it is hard to say how adaptable it truly is. The technology has not evolved or had many changes made to it since its inception, it still accomplishes the same goals it did in the early 2000s. Also, there was little substantial news about ADS-B from 2010 to the present day aside from its implementation and the regulations made detailing when ADS-B use is required.

Overall, as the 2020 mandate hit and ADS-B is now required when operating in most airspaces the technology is something that pilots all over the country have to become accustomed to. This new system propelled the United States aviation industry forward to a modern satellite-based system which comes with a multitude of benefits when flying. Optimized routing, improved safety, reduced pollution, and increased airspace capacity to name a few of the benefits. It does not come without its controversies though, such as potential security risks, anger from pilots over the 2020 mandate, and the expensive nature of ADS-B installation for casual pilots. Generally speaking, the pros seem to far outweigh the cons and ADS-B is the technological breakthrough the aviation industry needed to make the transfer over into the modern world.

Discussion Questions

Could you see ADS-B, or technology with similar features and functions, being used in other infrastructure aside from aircrafts in the future?

Do you think ADS-B implementation should be a universal requirement?

Do you agree with the FAA's decision to mandate ADS-B for all aircraft?

What is next for the aviation industry now that ADS-B has been fully implemented?