The Surveillance and Broadcast Services' Western Service Area (SBS WSA) office provides oversight and management of all activities in the Western Service Area, including ADS-B implementation, budgeting, and planning. The SBS WSA office is also tasked with providing Wide Area Multilateration (WAM) Services in Juneau, Alaska; and various locations in the state of Colorado. The WAM system works by using sensors that send out signals that are received and sent back by aircraft responders. The system then uses the signals received by three or more sensors to triangulate the position of the aircraft. It sends that information to Denver Center, where it is used to put a target on a controller's scope.

The map below depicts the states that fall under the FAA's Surveillance and Broadcast Services' Western Service Area.

Western Service Area

Western Service Area Faces Unique Challenges

Several of the states that fall within the WSA have unique aviation challenges. For example, Alaska relies on aviation more than any other state. Less than 10 percent of the state is accessible by road (the state capitol, Juneau, is accessible only by air or ferry), and river transport is possible only a few months of the year. As a result, aviation is the primary and, in most cases, the only means of transport for Alaska's numerous remote villages. Unfortunately, most of these villages lack the aviation infrastructure found in the "lower 48". In addition, Alaska has approximately ten percent of the nation's air transport operators. Historically, this ten percent generated approximately 35 percent of the nation's air transport accidents. The flying challenges posed by Alaska's mountainous terrain and fierce winter climate together with the higher-than-average accident rate has made the quest for improved aviation safety in Alaska a major goal for the FAA and the Alaskan aviation community.


The Capstone Project began in Southwest Alaska in FY2001. It was designed to seek aviation safety and efficiency gains by accelerating new technology in Alaska and demonstrating capabilities for use nationally. Capstone linked multiple technology initiatives under the FAA, the Alaskan community, and aviation industry. One of these new technologies was ADS-B. Under Capstone, the FAA provided ADS-B ground equipment, avionics and datalink communication suites for commercial aircraft. The FAA also deployed a ground infrastructure for weather observation, datalink communications, surveillance, and Flight Information Services to improve safety and enable eventual implementation of new procedures.

The Bethel / Y-K Delta area served as the initial test bed since it is served by approximately 25 percent of the commercial aircraft in Alaska and has a proportionate number of accidents. A 2004 study by MITRE and the University of Alaska at Anchorage found that, from 2000 through 2004, the rate of accidents for Capstone-equipped aircraft was reduced by 47 percent.

Accident rates in Southeast Alaska have decreased since Capstone Phase II began implementing avionics and broadcast services. The cumulative Part 135 accident rate in Southeast Alaska for Capstone-equipped aircraft, from FY1990-FY2008, was approximately 37 percent less than that for non-equipped aircraft. As a result, the Capstone project paved the way for a national deployment of ADS-B and demonstrated that ADS-B would improve aviation safety in Alaska.

Today the SBS WSA office is building on the success of Capstone by deploying ADS-B in its designated states, including Alaska.

WSA ADS-B Deployment

The SBS WSA is working diligently to deploy ADS-B ground stations in 82 service volumes that covers that states of Alaska, Washington, Oregon, Colorado, California, Utah, Arizona, Montana, Idaho, Nevada, Wyoming, Hawaii and Guam.

Current WSA ADS-B deployment

Contacting the SBS Western Service Area

Federal Aviation Administration
222 West 7th Avenue, #14
SBS WSA Office (AJE-6A)
Anchorage, AK 99513

For more information, call the SBS WSA office at (907) 271-5780 or send us an email.