In a major step toward reducing reliance on a ground-based navigation infrastructure, the FAA has announced that Wide Area Augmentation System (WAAS) use is being extended from the current 250 feet above an airport’s surface to 200 feet for vertical instrument approaches.

WAAS will be available to all users equipped with the appropriate avionics. This change will enable WAAS vertical guidance procedures to achieve an operational capability similar to an instrument landing system, where suitable airport conditions exist. Those airports that do not have the appropriate conditions may require additional infrastructure and airspace upgrades.

WAAS-equipped commercial operators will gain access to Category I equivalent approach services at qualifying airports where there are no instrument landing systems. This will result in improved safety, including enhanced approach and landing operations in marginal weather.

“This is a significant milestone, moving us closer to our ultimate goal of a satellite-based airspace system,” said FAA Administrator Marion C. Blakey.

The FAA plans to expand the application of these lower minima approaches beyond current instrument landing system airports. The first procedures that allow operations down to 200 feet will be published in 2007. The FAA currently has more than 300 vertical guidance procedures and is expecting to publish 300 additional ones in 2006.

Originally commissioned in July 2003, WAAS was approved to provide vertical guidance down to 350 feet. Localizer performance with vertical guidance procedures down to 250 feet was later developed to take advantage of the increased performance provided by WAAS. Over the past two years, WAAS has provided coverage to roughly 99 percent of the continental United States and has been available 99.87 percent of the time. WAAS continually exceeds performance expectations.

WAAS is a satellite-based navigation system designed to improve the accuracy, availability and integrity of signals from Global Positioning System (GPS) satellites.

Although WAAS was designed for aviation users, it supports a wide variety of non-aviation uses including agriculture, surveying, recreation, and surface transportation, just to name a few. The WAAS signal has been available for non-safety applications since August 2000, and numerous manufacturers have developed WAAS-enabled GPS receivers for the consumer market. Today, there are millions of non-aviation WAAS-enabled GPS receivers in use. There are approximately 3,000 WAAS-equipped aviation users operating in the national airspace system.

FMI: www.faa.gov