Anchorage, AK — Under contract to the Federal Aviation Administration's (FAA's) Capstone Program Office in Anchorage, Alaska, General Dynamics Decision Systems, a business unit of General Dynamics, successfully demonstrated a direct small aircraft-to-satellite navigation communications data link capability during a round trip test flight.
Using a University of Alaska Cessna 180, General Dynamics conducted its proof-of-concept demonstration using a Motorola hand held satellite telephone to transmit a live stream of aircraft position data, via the Iridium satellite system, to the Air Route Traffic Control Center (ARTCC) in Anchorage. The test flight departed Merrill Field, proceeded along the Knik Arm of Cook Inlet, past Pioneer Peak, and continued deep into the Knik Glacier valley.
"This successful testing of the integration of the Capstone's navigation and surveillance elements with the General Dynamics innovative satellite communications technique shows tremendous promise for enhanced navigation, safety, and security for Capstone equipped aircraft in Alaska, and realistic potential for many areas in the entire National Airspace System," said Ellis McElroy, FAA's Capstone Business Manager.
"We essentially were able to bring the benefits of satellite technology to smaller aircraft like those flown by pilots in Alaska," said Michel Gelinas, a program manager with General Dynamics. "Previously, these flight safety services were only available to large commercial and military aircraft."
Capstone is the name given to an avionics suite installed in over 150 small aircraft that greatly enhances the pilot's situational awareness, navigation, and surveillance abilities. Capstone's avionics suite includes a satellite Global Positioning System receiver, a data link transceiver, a multifunction display showing aircraft position, course, speed, altitude, projected flight path, weather, as well as aerial positions of other Capstone equipped aircraft. All the integrated flight information data (packets) are broadcast once per second to other nearby Capstone aircraft and to Ground Based Transceivers (GBT) stations then, in turn, to the FAA Air Route Traffic Control Center that can track the aircraft in spite of high terrain blocking normal radar.
"A significant element of this successful test is that Capstone equipped aircraft will be able to utilize a space-based backup data link system in extremely remote areas of Alaska where GBT stations may not be practical to install," said McElroy. "Besides enhancing safety, the use of General Dynamics unique and innovative system could save thousands of dollars in the high cost of building, operating, and maintaining numerous GBTs otherwise required in extremely remote areas."
During the test flight, a computer at the ARTCC in Anchorage plotted two independent flight tracks of the aircraft's position using both the Capstone GBTs and satellite telephone transmissions. Observing the tracks were representatives from the FAA, Alaska Department of Transportation, the Aircraft Owners' and Pilots Association, Alaska Airmen's Association, the U.S. Army, and the U.S. Air Force.
"As expected, the two independent flight tracks correlated extremely well. When the Cessna passed Pioneer peak and lost sight of the Site Summit GBT, the Capstone ADS-B aircraft position reports ceased. As this occurred, the Iridium aircraft tracking messages continued to be received and displayed seamlessly," said Sky Tudor, FAA's Capstone System Specialist.
In the future, Capstone avionics suites may be configured to incorporate this kind of space-based data link backup system providing an automatic function of switching from one navigation communications method to the other as an aircraft enters and exists GBT coverage.
[Supplemental Background to News Release]
Space-based navigation technique integrated with FAA's Capstone
[Capstone is a multi-faceted Alaskan aviation safety initiative that utilizes Automatic Dependent Surveillance-Broadcast (ADS-B) technology to provide several services including the radar-like surveillance, or flight monitoring, of small aircraft in non-radar airspace. With the Capstone system, an on-board avionics suite determines the aircraft's current Global Positioning System location, altitude, and other information, which is inserted into a digital datalink message stream that is broadcast automatically, once-per-second, directly to other like-equipped airplanes and to ground based transceivers (GBT's) strategically located from 60- to 100-miles apart.]
General Dynamics Satellite Communications Link for Aviation Safety
[Under contract to the Federal Aviation Administration's (FAA's) Capstone Program Office in Anchorage, Alaska, General Dynamics Decision Systems, is a business unit of General Dynamics. General Dynamics is currently under contract with the Defense Information Systems Agency (DSIA) to operate and maintain the U.S. Department of Defense Iridium gateway and to develop and manufacture the security module for the Motorola Satellite Series 9505 portable telephone.]
- General Dynamics Decision System's proof-of-concept demonstration utilized the Iridium Satellite LLC communications system, a constellation of 66 operational low earth orbit satellites (LEOS) deployed in six polar orbit planes. (With a hand-held Motorola Satellite Series 9505 phone, a message can be transmitted from any point on the globe directly to an overhead satellite that relays the message via successive satellites until it is down linked to the intended hand-held telephone.)
- While the system uses a downlink data stream from the airplane for Air Traffic and flight locating purposes, it is also possible to uplink Flight Information including "real time" local weather and forecasts, pilot reports, and graphical information such as temporary airspace restrictions.
- Capstone staff configured a Motorola Iridium telephone, connecting it to a roof-mounted antenna to receive the flow of airplane position data down linked from the satellite. The developmental Capstone Communications and Control System (CCCS) computer was reprogrammed to merge the routine Capstone ADS-B position messages from Site Summit GBT with those delivered via the Iridium telephone system.
- FAA engineers estimate over 140 Ground Based Transceivers (GBT's) will be needed to deliver the desired ADS-B service volume in Alaska; a number of these will have to be situated in extremely remote locations such as frequently used mountain passes. General Dynamics Decision System's successfully demonstrated direct small aircraft-to-satellite navigation communications data link capability can be a supplement to the land-based GBT system providing a direct satellite communications link capability, thus allowing tracking coverage in very remote mountainous areas of Alaska without a GBT.
- During the test flight, the certified Capstone avionics system (while in line-of-sight) communicated enroute with FAA's GBT at Site Summit. Additionally, a hand held Motorola Series 9505 telephone was transmitting a live stream of airplane position data to a similar phone at Anchorage Air Route Traffic Control Center (ARTCC). (The airborne Iridium telephone was fitted with a special 3-inch diameter antenna and interconnected with a hand-held GPS receiver and a battery powered laptop computer that automatically assembled GPS position reports into the Capstone message packet format. The phone then up-linked the aircraft position messages directly to the Iridium satellite.)
- When the Cessna passed Pioneer peak and lost sight of the Site Summit GBT, the Capstone ADS-B aircraft position reports ceased. As this occurred, the Iridium aircraft tracking messages continued to be received and displayed seamlessly. On its homeward leg, as the aircraft passed Pioneer Peak, the Site Summit GBT reacquired the aircraft's ADS-B signal for the remainder of the flight, including landing rollout and taxi to the UAA hangar.