Feature Articles
Paradox Case Demonstrates Coast Guard Airborne Search and Rescue Capability
By Hunter C. Keeter
A thermal image showing the capsized SV Paradox and its crew, whose rescue
was facilitated by the DF-430 equipment aboard a CGAS Clearwater-based HC-130H.
(USCG photo)
An HC-130H from Coast Guard Air Station Clearwater, Fla., with state of the art technology, has heralded a new era of airborne search and rescue (SAR) capability. On the night of 11 April 2007, HC-130H No. 1504 added to a string of recent successes when it located the stricken sailing vessel Paradox and helped save the lives of its crew. The 1504, equipped with new direction finding equipment provided by the Integrated Deepwater System program, had accomplished the mission after other platforms and legacy SAR capabilities had been unable to do so.
“In this case we had a large catamaran, 35–40 feet long, that had completely turtled. The skipper had a battery powered saws-all and had cut an escape hole through the hull,” Lt. Cmdr. Douglas E. Williams, C-130 standardization officer, and aircraft commander during the Paradox SAR, told the Deepwater News in an interview. “They had the [Emergency Position-Indicating Radio Beacon (EPIRB)] inside the hull, transmitting straight up from that hole. We got a solid hit on the new DF-430 multi-mission direction finder and got over the top [of the rescue] quickly. … District Seven Command Center was able to vector in an HH-60J helicopter from CGAS Clearwater to complete the rescue.”
Previously, a Coast Guard HU-25 Guardian, not equipped with the new DF-430, had been unable to locate the Paradox. Williams said that in his experience, legacy EPIRB signals would be picked up by an aircraft’s direction finding equipment only about 20 percent of the time. The other 80 percent of the time, aircrews would fly laborious search patterns over the ocean, which cost precious time and fuel.
Typical EPRIB beacons use one of two signals –406MHz or 121.5MHz. The 406MHz signal emanates every 52 seconds at 5W, on a 24-hour battery and is approximately 200 times stronger than the legacy 121.5MHz transmission. The 406MHz signal may be detected from as far away as 100 nautical miles. While weaker, the legacy 121.5MHz signal has the benefit of using less power and of providing rescuers with a constant homing beacon at short range. That may be important for the end-game of a SAR, as an aircraft closes in and needs the constant beacon to locate the source of the EPIRB transmission.
In a typical SAR mission, a Coast Guard aircrew follows a needle on their direction finding equipment, pointing the way toward the source of an EPIRB’s signal. When the aircraft makes “station passage,” or passes directly over the signal source, the pilot turns around, setting up an orbit to allow the aircrew to locate the target visually. The DF-430 direction finding equipment automatically switches from the longer range 406MHz signal, to the more frequent but weaker emanations of the 121.5MHz system, at 15 nautical miles or less.
EPIRB devices transmit their signals to a constellation of four satellites maintained by the International Cospas-Sarsat Programme. The constellation includes two Russian Cospas satellites (in near-polar orbits) and two U.S. National Oceanographic and Atmospheric Administration (NOAA) meteorological satellites (also in near-polar orbits). Canada and France provide the satellites with 121.5MHz and 406MHz instrument payloads. Operational since 1979, the Cospas-Sarsat system has helped to rescue more than 20,000 people world wide, according to http://www.cospas-sarsat.org/
Significant to Deepwater’s acquisition of the DF-430 equipment, the International Cospas-Sarsat Programme plans to switch over its satellite receivers from 121.5MHz exclusively to 406MHz, by 1 February 2009. The plan has met with some scepticism from the international search and rescue operational community, including the Coast Guard. However, new equipment such as the DF-430 may prove essential to overcome potential technology gaps in search and rescue capability as the legacy satellite signal receivers are phased out.
The Deepwater program has provided $2.6 million to buy 27 DF-430 406MHz direction finders for all HC-130Hs and other Coast Guard aircraft.
The Rockwell Collins DF-430 direction finder has a frequency range of 30MHz–410MHz, and is designed to support SAR and other civil, military and naval missions. So far, the DF-430 gear has been installed aboard HC-130H No. 1504, which received the prototype system used for initial testing in fiscal year 2005. The 1504 now is based at Clearwater, where several real-world rescues have put its capabilities to the test.
A second aircraft, HC-130H, No. 1704, is in the final stages of testing and evaluation with the first permanent installation of the DF-430 equipment. Currently at US Coast Guard Aircraft Repair and Supply Center (ARSC) Elizabeth City, N.C., the aircraft is undergoing ground and flight testing. Once testing is completed, 1704 will be transferred to Sacramento, Calif.
Later in May, another six ship-sets of equipment are to be delivered to the Coast Guard, for additional HC-130H aircraft destined for duty at Clearwater; Air Station Barber’s Point, Hawaii; Air Station Kodiak, Alaska; Sacramento; and Elizabeth City.
Ultimately, the upgrade is planned for every Coast Guard aircraft in inventory, including HH-65 and HH-60 helicopters, and HC-144A maritime patrol aircraft. Additionally, the DF-430 equipment may be installed aboard the service’s Dassault Falcon jets, designated HU-25 Guardians in Coast Guard service. The Falcons are scheduled to be decommissioned between 2009–2014, but may remain in service for some time, inviting some equipment modernization, according to Coast Guard officials.
Airborne SAR, using systems like the DF-430, is one of the arrows in the Coast Guard’s quiver of search and rescue capabilities. Other team mates in the service’s multi-tiered approach to SAR include shore communication sites. According to the Coast Guard, 90 percent of SAR cases occur within 20 nautical miles of the coastline, which is the territory of the service’s $730 million Rescue 21 program.
Rescue 21 is a new command, control and communications system that is more robust, reliable and capable than the legacy National Distress and Response System (NDRS). Rescue 21 equipment includes shore based antenna towers that are able to receive marine radio transmissions, including VHF and UHF, as well as 121.5MHz EPIRB signals, and 243MHz military aircraft distress beacons. Coast Guard aviation’s DF-430 406MHz direction finding equipment complements the capabilities of Rescue 21.
On shore and in the air, the Coast Guard’s search and rescue capabilities vouchsafe marine safety every day, along more than 95,000 miles of U.S. coast line and well out to sea. As new technologies are introduced, and as legacy systems are modernized and recapitalized, the service is pushing back the limits of time and distance, saving lives in the process.
“Ultimately this is about expanding the SAR mission capability, surface assets, satellites, aviation assets,” Lt. Cmdr. Joseph E. Deer, the Integrated Deepwater System’s HC-144A platform manager, and an expert with the DF-430 equipment, said in an interview. “We want to save lives and the [DF-430] is an electronic advancement that allows us to do that. We are going to reap a number of benefits, such as savings on fuel and time. That means SAR is going to be safer for the people we are looking for, and for the air crews doing the mission.”
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