Excerpt from U.S. Coast Guard “Proceedings of the Marine Safety & Security Council” magazine by LT Myles Greenway, Chief, Investigations Division, U.S. Coast Guard Sector Charleston.
The Coast Guard received disturbing news following the rescue of the captain of the F/V Still Crazy V, which sank off the coast of South Carolina in 1999. The captain reported that although he held his emergency position-indicating radio beacon (EPIRB) and saw Coast Guard helicopters, they couldn’t locate him.
Troubled by what the master told him, Greg Johnson, Sector Charleston’s commercial fishing vessel safety examiner, promised to look into the matter.
Following this incident, Johnson analyzed data from EPIRB activations and aircraft sorties and identified more than 100 instances in which Coast Guard aircraft detected an EPIRB’s 121.5-MHz homing signal, but were not equipped to detect the stronger 406-MHz signal.
Testing EPIRBs and Coast Guard Equipment
In 2001, the Seventh Coast Guard District forwarded Johnson’s findings to USCG headquarters. Personnel tested 406-MHz EPIRBs and the current Coast Guard aircraft direction-finding equipment.
Testing indicated that signal strength could be affected when the device is held close to a mariner’s body. Additional testing indicated that, under ideal weather conditions, a Coast Guard HH-65 helicopter equipped with the existing direction-finding equipment could locate an unencumbered EPIRB 20 nautical miles away at an elevation of 3,000 feet.
Meanwhile, Back at Sector Charleston
While testing continued, Johnson consulted with Coast Guard aviators and foreign exchange pilots and learned that the Canadian Air Force had begun installing new direction-finding equipment on their C-130s. He also discovered that the Coast Guard Aviation Logistics Center was considering the same equipment that provided 360-degree scanning capability and minimized false bearing indications.
Johnson shared his research with the Aviation Logistics Center. Buoyed by his data, the center installed the prototype aboard a Coast Guard C-130, tail number 1504, and tested off the coast of Charleston. The flight data proved the new equipment performed as designed—it locked onto an EPIRB’s 406-MHz signal at nearly twice the distance as compared to the existing equipment for the 121.5-MHz frequency.
On June 10, 2005, the sport fisher Extractor capsized while evading tropical storm Arlene. Coast Guard aircraft searched more than 13,000 square miles of ocean for the two crewmembers with negative results. Before running out of daylight, District Seven requested Coast Guard C-130, tail number 1504.
While transiting to the search area, the prototype unit locked onto the EPIRB’s 406-MHz signal from more than 90 nautical miles away at an elevation of 17,000 feet. C-130 personnel successfully vectored a Coast Guard helicopter to the crew, who had been hanging onto the capsized vessel for more than 26 hours.
As of March 2009, the Coast Guard equipped all of its fixed-wing aircraft with the new direction finders. More significantly, the equipment has assisted Coast Guard in the successful rescue of more than 50 mariners to date.
Pictured: Greg Johnson receives the DHS Secretary’s Award for Excellence for his research.
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Full article is available at http://www.uscg.mil/proceedings/winter2009.
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