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.
At 10:31, BTV received a call from AFRCC to begin investigating an ELT incident, which prompted FAA personnel to link the ELT incident with the PA-32-300 airplane. At 11:04, Boston ATC learned from the New York TRACON that a controller had “worked” the PA-32-300 and that the pilot had cancelled his IFR flight plan and changed his destination to Barnes Municipal Airport (BAF), Westfield, Mass., due to icing. Also about 11:04, specialists at BTV notified the Massachusetts State Police and Great Barrington Police Department of the reported ELT signal.
In the meantime, Boston controllers received a notification from the Bradley, Conn., (BDL) TRACON that an airplane had received a strong ELT signal in the vicinity of the “MOBBS” intersection. Boston reported this finding to AFRCC at 11:16, relaying that the PA-32-300 was overdue, but may have landed at BAF. At 11:23, Boston completed a National Track Analysis Program (NTAP) and reported to AFRCC that the last known position of the airplane was about three miles south-southeast of Canaan, Conn.
At 11:26, Boston notified BTV that the pilot had cancelled his IFR flight plan with the New York TRACON controller, continued VFR and may have diverted to BAF. The controller added that “the last hit coincides with where they’re getting those ELT reports.” Ten minutes later, Boston received a call from the police reporting that they didn’t find the airplane. Boston then called AFRCC and asked if a search had been initiated at the last NTAP coordinates. AFRCC then called the Massachusetts Civil Air Patrol (CAP) to open the ELT incident with them at 11:43.
At 11:48, Boston controllers contacted the Connecticut State Police and notified them about a possible airplane accident in the Canaan/Sheffield area. Several minutes later, Boston controllers confirmed with AFRCC that the last radar hits were just south of Canaan, at 2,200 feet, at 6:50:59. At 12:06 a.m., BTV notified the Massachusetts State Police of the ELT signal near Sheffield. The Massachusetts State Police immediately notified the Sheffield Police Department, who contacted BTV seeking additional information.
Between 12:06 and 1:45, search-and-rescue operations intensified. At 1:53, AFRCC called the Air Force 84th Radar Valuation Squadron (84th RADES) and requested data recorded from Air Force radar, which might show the PA-32-300. At 2:30, Massachusetts State Police reported that their helicopters were unable to fly due to the extreme weather conditions (25 mph winds with gusts to 40 mph expected). At 2:50, the Massachusetts CAP reported to AFRCC that four ground teams had launched and another airplane was preparing to launch.
Between 3:00 and approximately 4:30 a.m., the Sheffield Police and Fire Departments and the Connecticut CAP ground team searched the ELT coordinates near Sheffield with negative results. At 3:49, 84th RADES contacted AFRCC and reported the last known position of the airplane to be just north of Sharon, Conn., at 6:47, at an altitude of 3,300 feet. These coordinates were based on data obtained from the Riverhead, N.Y., radar facility. The 84th RADES, however, didn’t access radar data from another radar facility, which showed the airplane continuing to a position near Ashley Falls, Mass., and changing its transponder code from 3377
At 6:16 a.m., a Massachusetts CAP airplane reported a strong 121.5 MHz signal in the vicinity of Chester, Mass. At least one ground team responded to that location. The Massachusetts State Police notified the New York State Police Air Wing of the ongoing search and requested helicopters to search the areas of Sharon and Sheffield. At approximately 8:00, two New York State Police helicopters launched.
At 8:42, a Massachusetts CAP airplane reported another strong ELT signal in the area of Chester, and a Connecticut CAP ground team again responded to the coordinates with negative results. At 9:48, a Massachusetts CAP airplane reported another strong ELT signal. The Connecticut CAP ground team met up with a Massachusetts CAP ground team and drove to the area of those coordinates.
While these two ground teams were en route to the latest coordinates, Boston controllers called AFRCC and provided a new last-known position based on a second NTAP data extraction. When Boston controllers performed the original data extraction, they didn’t realize that the program switched to a subsequent recording tape during a small gap in the radar returns. After reviewing the data the next morning, the error became apparent. AFRCC provided the new last-known position to the Massachusetts CAP at 10:43. In the meantime, the two New York State Police helicopters refueled at Great Barrington Airport. During refueling, the pilots received new search coordinates. At 10:57, the Connecticut and Massachusetts CAP ground teams reached a road intersection, near coordinates provided by the Massachusetts CAP airplane. The ground teams were led into the woods by the search airplane at 11:00. At 12:15, one of the New York State Police helicopters arrived at the new coordinates, which were approximately three miles west of the crash site. After a short search, the wreckage of the airplane was located at 12:26 p.m. The fuselage was almost intact. The aircraft’s wings had been ripped off. One of the survivors put an arm outside of the cabin, waving to rescuers. One of the children was found alive about 40 feet from the cabin.
The weather observation taken at Pittsfield, Mass., about 15 miles north of the accident site, at about the time of the accident included wind from 300 degrees at 16 knots, gusting to 22 knots; visibility eight miles; few clouds at 900 feet, broken ceiling at 1,300 feet, overcast at 1,800 feet; temperature one degree C; dew point minus-two degrees C.
The NTSB determined that the probable cause of this accident was the pilot’s improper decision to attempt a VFR flight in marginal VFR weather conditions over mountainous terrain, which resulted in an in-flight collision with trees. Factors in this accident were clouds and night-light conditions.
Peter Katz is editor and publisher of NTSB Reporter, an independent monthly update on aircraft accident investigations and other news concerning the National Transportation Safety Board. To subscribe, write to: NTSB Reporter, Subscription Dept., P.O. Box 831, White Plains, NY 10602-0831.