FAA Lowers Minimums For WAAS
Use of the Wide Area Augmentation System (WAAS) will be extended to allow operations within 200 feet above touchdown zone elevation, or height above touchdown (HAT), equivalent to the standard ILS Category I HAT, the FAA said Friday, a move that will provide more precision, all-weather approaches and will increase capacity at thousands of GA airports. "WAAS moves us another step closer to a satellite-based airspace system," FAA Administrator Marion Blakey said in a news release. "Less reliance on a ground-based infrastructure will result in improved safety, including enhanced approach and landing operations in marginal weather." The FAA plans to make these vertical-guidance approaches available at airports where there are no instrument landing systems. The lower minimums may require more stringent requirements for some airfields. Those airports that do not have the appropriate conditions for vertical-guidance approaches may require additional infrastructure and airspace upgrades. WAAS will be available to all pilots whose aircraft are equipped with the appropriate avionics, both GA pilots and commercial operators, the FAA said. The first procedures that allow operations down to 200 feet will be published in 2007. The FAA currently has more than 300 instrument procedures providing vertical guidance to higher HATs and is expecting to publish 300 additional procedures in 2006.
WAAS is a satellite-based navigation system designed to improve the accuracy, availability and integrity of signals from Global Positioning System (GPS) satellites. Before WAAS, the U.S. did not have the ability to provide horizontal and vertical navigation for precision approach operations for all users at all locations. WAAS will improve capacity and safety and will eventually reduce operations costs for the FAA by enabling the removal of a portion of existing ground-based navigation infrastructure. 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.