Marginal Weather, Cannabis Use Factors in Fatal Controlled Flight into Terrain Accident near Lutsel K'e, Northwest Territories
EDMONTON, AB, March 20, 2013 /CNW/ - The Transportation Safety Board of Canada (TSB) today released its investigation report (A11W0151) into the controlled flight into terrain (CFIT) accident on 4 October 2011 that involved a Cessna 208B Caravan operated by Air Tindi Ltd. near Lutsel K'e, Northwest Territories.
The Cessna Caravan was operating under visual flight rules (VFR), under which the pilot must maintain constant visual reference to the ground. The flight departed during daylight hours from Yellowknife to Lutsel K'e, Northwest Territories, with one pilot and three passengers aboard. When it did not arrive on time, a search was launched, and the aircraft was found 26 nautical miles west of Lutsel K'e on high terrain near the crest of Pehtei Peninsula. The pilot and one passenger were fatally injured, and the two other passengers were seriously injured. Although no emergency locator transmitter (ELT) signal had been received, it was found to be operational when the search team found the aircraft.
The aircraft was flown at low altitude into an area of low forward visibility, which prevented the pilot from seeing and avoiding terrain. Weather during the accident flight was marginal for VFR flight, and the aircraft did not have a terrain awareness and warning system (TAWS) or terrain-warning features on its GPS. The pilot, aircraft and company were all qualified to operate under instrument flight rules (IFR), under which pilots fly using cockpit instruments rather than visual references. Flying under IFR would have provided a margin of safety given the weather conditions. It could not be determined why the pilot chose to fly under VFR.
Toxicology testing revealed that concentrations of cannabinoids found in the pilot's bloodstream were sufficient to have impaired pilot performance and decision-making during the flight.
Since the accident, Air Tindi has taken measures to improve safety, such as dispatching all scheduled flights under IFR; installing cockpit imaging and flight data monitoring devices in its Cessna 208B fleet; and introducing random drug and alcohol tests for employees in safety-sensitive positions.
The ELT manufacturer made changes to its ELT designs to improve signal detection, and it also revised the instructions on how to secure ELT installations properly in aircraft. Canadian, U.S., and European regulators have taken steps to raise awareness of the need for adequate instructions to ensure that hook and loop (Velcro) fasteners securing ELTs are sufficiently tightened, and the FAA for its part has changed the design criteria for all new ELTs to exclude hook and loop fastener mounting systems.
Transport Canada enacted regulations requiring TAWS to be installed in all turbine-powered aircraft with 6 or more passenger seats by July 2014.
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The TSB is an independent agency that investigates marine, pipeline, railway and aviation transportation occurrences. Its sole aim is the advancement of transportation safety. It is not the function of the Board to assign fault or determine civil or criminal liability.
SOURCE: Transportation Safety Board of CanadaFor further information:
Transportation Safety Board of Canada