Centerlines - January 2008 - (Page 9)

POLICY CENTER ADS-B: What’s in It for Airports? AUTOMATIC DEPENDENT SURVEILLANCE– BROADCAST MODE (ADS-B) is the cornerstone of Federal Aviation Administration’s (FAA) Next Generation Air Transportation System (NextGen), promising improved safety, increased capacity and reduced delays. But how did we get to ADS-B, what does it promise and what is the reality for airports? ity, permitting reduced separations and obstacle clearance. In addition, suitably equipped aircraft can “see” nearby traffic and, eventually, are expected to be able to perform certain self-separation functions. Trials in Alaska and at the United Parcel Service hub in Louisville have confirmed some of the safety and selfseparation advantages of ADS-B. Performance Limitations FAA’s current plans are to certify that ADS-B can perform at least as well as today’s radar and will support independent instrument approaches to runways separated by 4,300 feet. While it is logical to conduct tests to assure that the new technology is at least as good as the old one, it is troubling that there is no current activity to increase ADSB performance beyond that of existing radar. In order to gain significant benefit, airports need Navigational Aid System (NAVAIDS) that will Limitations of Radar In 1956 and 1960, two tragic midair collisions over the Grand Canyon and New York City galvanized the aviation industry and led to a decision to provide nationwide radar surveillance of commercial flights. Radar, supplemented with the use of aircraft transponders, has been the core of air traffic control (ATC) surveillance ever since. However, errors ACI-NA is committed to working with FAA in the aircraft position reported by radar increase with distance and require large separations between aircraft and over obstacles. and the airlines for air traffic modernization. support independent instrument approaches to at least the 3,000foot runway spacing allowed by today’s precision runway monitor. In order to make significant advances, independent instrument approaches to runways spaced as closely as 1,000 (or even 700) feet are also needed. More troubling, the performance of basic GPS, which will provide most air carrier aircraft position information, is likely inadequate to support ADS-B surveillance for approaches closer than 4,300 feet. The primary solution being Advantages of ADS-B ADS-B is based on aircraft selfreporting its position, primarily from global positioning satellites (GPS), and the position accuracy is not only better than radar, but it also remains constant at any distance. Basically, the aircraft broadcasts its position (and other information) to ground sensors and to other suitably equipped aircraft in the vicin- discussed by FAA is the use of the Wide Area Augmentation System (WAAS) to improve GPS performance. However, air carriers are generally not equipped to utilize WAAS because they are anticipating equipping their airplanes to take advantage of the higher precision Local Area Augmentation System (LAAS). FAA’s justification for LAAS does not include these closely spaced approaches, and FAA benefit cost studies based on LAAS-enabled Category II/III approaches do not appear favorable. The only other solution being discussed for the GPS accuracy problem is the addition of more satellites, either by the Department of Defense or in the European Galileo program. Finally, the benefits being attributed to ADS-B require a level of equipage by airlines that are only planned for the later years in the deployment schedule. Unless procedures are developed to deliver benefit to air carriers, such as reduced restrictions on approaches to closely spaced parallel runways, it is uncertain whether they will invest in the needed equipment and unclear if the advertised ADS-B benefits for airports will be realized at all. ACI-NA is committed to working with FAA and the airlines for air traffic modernization. While we agree that ADS-B is an important component in the move to NextGen, we believe FAA should be realistic in describing the benefits for airports. The industry has shown it is willing to invest to enhance the safety and security of airport operations, but we must ensure those investments will yield the greatest benefit. ■ DICK MARCHI SENIOR ADVISOR, POLICY AND REGULATORY AFFAIRS ACI-NA | CENTERLINES 9

Table of Contents for the Digital Edition of Centerlines - January 2008

President’s Message
Canadian Airports
Associates’ Corner
Policy Center
Regulatory Front
On the Hill and On the Stump
One on One: Dave Barger
Revenue: The Concessions Awards
Environment: O’Hare Expansion
Passenger Focus: Houston Friendly
Safety and Security: After Comair, What Next?
Air Service Recruiting: Charleston’s Acquisition of AirTran
On Management: Performance Benchmarking at DFW
Now Underway
Grand Opening
Conference Previews and Reviews
New Members
Index of Advertisers/
Box Scores

Centerlines - January 2008