BRENDAN SOBIE / BETHEL, ALASKA
Capstone GPS-based system will begin phase two tests this year with plans to extend technologies for phase three
The US Federal Aviation Administration is to extend its Capstone free-flight technology trials to south-east Alaska and begin testing the global positioning system-based wide-area augmentation system (WAAS).
Free-flight co-ordinator Gary Childers says phase two of Capstone will begin later this year, aimed at bringing instrument flight rules (IFR) flying to the Juneau region using WAAS. Most airports in south-east Alaska have to be closed in IFR conditions because the mountainous terrain precludes traditional instrument approaches. Regulations only permit IFR approaches using ground-based navigation aids, but Childers says the Capstone office is seeking an exemption to use WAAS as a stand-alone IFR navigation tool.
Capstone avionics will be fitted on a Juneau-based FAA aircraft by 1 October, and on a helicopter by November. Government-funded installations on independently owned general aviation (GA) and air taxi aircraft in the region should begin in February and be completed in early 2004. Subsequent tests will run for three to five years.
The FAA envisages Capstone being the first user of WAAS, which is scheduled to be operational next year, allowing instrument approaches down to 300ft (90m). WAAS-based airways will also be mapped out and new communication equipment installed on mountainsides to eliminate areas where controllers have no radio contact with pilots. Two technologies - multilateration and traffic information service-broadcast - will also be tested as part of the $40 million phase two project.
The FAA has installed Capstone avionics, manufactured by UPS Aviation Technologies, on 177 aircraft based in western Alaska as part of phase one, which has been extended for two more years. Capstone features automatic dependent surveillance-broadcast (ADS-B) traffic displays that allow controllers and dispatchers to monitor flights, and pilots to spot other traffic. The Capstone cockpit display also provides terrain and weather data.
A third ADS-B ground station was installed in western Alaska in August and ADS-B displays were installed in the Bethel VFR-only control tower in July. The Capstone office also aims to improve the accuracy of ADS-B as a radar-like surveillance service. Childers says this upgrade should allow Anchorage-based controllers to cut the separation between ADS-B equipped aircraft in non-radar areas from 5nm (9km) to 3nm.
The Juneau region was originally selected as the Capstone test site, but the FAA decided it would be safer to test the technology first in the flat Yukon-Kuskokwim Delta of western Alaska. The FAA has earmarked northern Alaska for the third phase of the programme, but there are plans to extend some of the technologies to continental USA and, potentially, to larger operators.
The FAA plans to install a ground station in Arizona to support 85 GA aircraft as part of a trial overseen by Embry-Riddle Aeronautical University. The agency has also awarded Boeing a contract to test Capstone technologies, initially on helicopters but possibly later on commercial aircraft, in the Gulf of Mexico.
Source: Flight International
