May 17, 2012 - The Department of Transportation’s Office of Inspector General (OIG) plans to initiate an audit of the Federal Aviation Administration’s (FAA) progress in implementing the Automatic Dependent Surveillance Broadcast (ADS-B) program.

ADS-B will supplement radar by leveraging satellite-based technology, aircraft avionics, and ground-based systems to provide information on the position of aircraft to pilots and air traffic controllers in all phases of flight.

Automatic Dependent Surveillance-Broadcast (ADS-B) is a surveillance technology for tracking aircraft as part of the Next Generation Air Transportation System (NextGen). The United States will require the majority of aircraft operating within its airspace to be equipped with some form of ADS-B Out by January 1, 2020. 

ADS-B is a cornerstone of efforts to modernize air traffic control from its present state into the Next Generation Air Transportation System. OIG will be conducting this review at the request of the Chairman and Ranking Minority Member of the House Committee on Appropriations, Subcommittee on Transportation, Housing and Urban Development, and Related Agencies.   

OIG audit will also address requirements in the FAA Modernization and Reform Act of 2012 to conduct an annual review of the ADS-B program. Their audit objective is to assess FAA’s progress with mitigating risks and addressing challenges associated with implementation of ADS-B.  

The ADS-B program will supplement radar by leveraging satellite-based technology, aircraft avionics, and ground-based systems to provide information on the position of aircraft to pilots and air traffic controllers in all phases of flight.  

The successful implementation of ADS-B is critical to realize the benefits of FAA’s plans to increase the safety and overall efficiency of the National Airspace System. FAA has spent almost $900 million on ADS-B since 2007 and plans to spend an additional $1 billion between fiscal years 2012 and 2016. 

OIG’s previous work on the ADS-B program identified risks in several key areas that will directly impact the cost, schedule, and expected benefits of ADS-B: aircraft equipage, controller/pilot procedures, impact of more aircraft using an already crowded radio frequency, integration with automation systems controllers rely on to manage air traffic, and potential security vulnerabilities.  

ADS-B, which consists of two different services ADS–B Out and ADS–B In, will be replacing radar as the primary surveillance method for controlling aircraft worldwide. In the United States, ADS-B is an integral component of the NextGen National Airspace strategy for upgrading/enhancing aviation infrastructure and operations.  

The ADS-B system can also provide traffic and government generated graphical weather information through TIS-B and FIS-B applications. ADS-B enhances safety by making an aircraft visible, realtime, to ATC and to other appropriately equipped ADS-B aircraft with position and velocity data transmitted every second. ADS-B data can be recorded and downloaded for post flight analysis. ADS-B also provides the data infrastructure for inexpensive flight tracking, planning and dispatch.

The system relies on two avionics components—a high-integrity GPS navigation source and a datalink (ADS-B unit). There are several types of certified ADS-B data links, but the most common ones operate at 1090 MHz, essentially a modified Mode S transponder, or at 978 MHz (USA only).