[Avionics Magazine 06-27-2016] The Transportation Safety Board (TSB) of Canada is recommending new Emergency Locator Transmitter (ELT) standards after completing an investigation into an air ambulance accident that occurred in May 2013. TSB’s recommendations seek for Transport Canada (TC) to require Canadian operators to equip their aircraft with at least one ELT capable of transmitting 406 MHz signals, to bring the Canadian flying community up to previously established International Civil Aviation Organization (ICAO) ELT standards.
TSB is recommending new ELT regulation for Canadian-registered aircraft. Photo: McMurdo Group.
TSB’s recommendations come following its investigation into the crash of a Sikorsky S-76A configured as an air ambulance, operated by Canada’s largest air ambulance operator, Ontario-based Ornge. According to the TSB investigative report released June 15, the helicopter crashed into an area of dense bushes and swampy terrain shortly after making a left hand turn approximately 119 nautical miles northwest of the Moosonee Airport. Ornge’s S-76 was equipped with a satellite tracking system that reported a message after takeoff and then went inactive. Cospas-Sarsat, the international satellite-based Search and Rescue (SAR) distress alert detection and information distribution system Canada uses to locate downed aircraft, did not detect the helicopter’s ELT.
The two pilots and paramedics onboard died as a result of the crash. TSB officials discovered that the S-76A involved in the crash was manufactured in 1980, and had accumulated 15,600 flight hours and 48,400 landings prior to the fatal Ornge incident in May 2013, however the helicopter had no known deficiencies up to that point.
A review of the wreckage described by TSB in the investigative report showed that the helicopter was equipped with a Kannad 406 MHz ELT, which was severely damaged when discovered by SAR personnel. The ELT was found hanging by its wires and detached from its mounting tray, and the ELT antenna was also severely damaged.
“Testing of the ELT confirmed that it would be activated when subjected to impact forces that were within the specified ‘g’ range of the unit. This confirmation, in conjunction with the fact that the ELT’s battery pack was depleted, strongly suggests that the device did activate on impact and did transmit a signal. However, no signal was received due to the damaged antenna,” TSB said in the report. Based on this finding, TSB is recommending ELT hook and loop fasteners — the type that was featured on the Ornge S-76 — to be prohibited.
However, the report notes that the problems with the ELT go beyond the damaged antenna, and further points to a larger problem with Canadian aircraft ELT requirements.
In February 2009, Cospas-Sarsat stopped monitoring 121.5 MHz ELT signals. Last year, TC published a Notice of Proposed Amendment, seeking a Canadian airspace mandate for dual 121.5 MHz/406 MHz ELT equipage for aircraft registered in Canada. The investigation found that under the current regulations, approximately 27,000 Canadian-registered aircraft require an ELT. As of March 2016, TSB’s review of the Canadian aircraft registry found that only 10,086 Canadian-registered aircraft in TC’s Civil Aircraft Register database were equipped with at least one active 406 MHz ELT registered through the Canadian Beacon Registry.
“Of those aircraft, 5256 were private, 4604 were commercial, and the remaining 226 were state-owned. Therefore, more than half of all Canadian-registered aircraft that require an ELT are being operated with an ELT whose signal is not detectable by the Cospas-Sarsat system,” TSB wrote in its report.
The report also found “a considerable body of research now indicates that current ELT design standards do not ensure a reasonable degree of crash survivability.” Based on these findings, TSB issued recommendations to ICAO, the Radio Technical Commission for Aeronautics (RTCA), the European Organization for Civil Aviation Equipment (EUROCAE) and the Department of Transport to establish “rigorous ELT system crash survivability standards that reduce the likelihood that an ELT system will be rendered inoperative as a result of impact forces sustained during an aviation occurrence.” Additionally, TSB is seeking amendments for Cospas-Sarsat to the 406 MHz first-burst delay specifications to the “lowest possible timeframe to increase the likelihood that a distress signal will be transmitted and received by search-and-rescue agencies following an occurrence.”