A Needle In A Haystack
Current ELT systems can make life difficult for search and rescue
Sometime in 2009, the COSPAS-SARSAT satellite system will no longer be receiving distress signals on today’s common distress frequencies, 121.5 MHz and 243.0 MHz. Instead, the satellites will monitor only 406 MHz, a frequency that’s being phased in for civilian use. COSPAS-SARSAT is the satellite distress alerting system designed to pick up emergency locator transmitter (ELT) signals and relay activation alerts to the National Oceanic and Atmospheric Administration (NOAA), the U.S. Air Force Rescue Coordination Center and the U.S. Coast Guard Rescue Coordination Center.
The new 406 MHz ELTs encode information digitally and can transmit an aircraft’s identification number as well as its position derived from GPS information. Each 406 MHz ELT will have to be registered with NOAA. The promise of the updated satellite system is to reduce the time it takes to recognize an ELT alert, reduce the number of false alerts and locate the source of the distress signal within a mile or two, versus the 10 or 20 miles common with the old system.
Difficulties encountered by search-and-rescue agencies trying to pinpoint current ELTs were portrayed in the NTSB’s investigation of an accident that occurred in the Berkshire Mountains of Massachusetts on March 2, 2003. A Piper PA-32-300 Cherokee Six was on a flight from Lakeland, Fla., to Keene, N.H., with a family of seven on board. The airplane stopped at a small airport in Great Barrington, Mass., before continuing to Keene. Shortly after takeoff, the airplane crashed on a snow-covered mountain. Four members of the family survived the initial crash. One of them later died in a hospital. The survivors had spent about 18 hours in freezing temperatures before being rescued.
At 9:39 p.m., the Air Force Rescue Coordination Center (AFRCC) received an ELT signal from the COSPAS-SARSAT satellite system. The location was near the town of Sheffield, Mass., just over 11 miles southwest of the accident site. At 10:00, the Burlington (BTV) Automated Flight Service Station received a call from a relative of those on the flight. The individual reported speaking with the pilot via cell phone at 5:38, when the airplane was near Wilkes-Barre, Penn. He hadn’t been able to reach the pilot again despite repeated calls. BTV began contacting other FAA facilities requesting information about the airplane. About 10:22, Boston Air Traffic Control received a phone call from AFRCC opening an “incident” for the ELT signal near Sheffield.