Richmond, British Columbia, 25 February 2015 — In its report into a 2013 British Columbia (B.C.) float plane accident (A13P0278), the Transportation Safety Board of Canada (TSB) expressed its concern that, if multiple modifications are made without adequate documentation of the effects on aircraft handling, pilots may lose control of the aircraft due to unknown aircraft performance.
“Pilots need accurate information on how an aircraft will fly after modifications have been made to it,” said Joseph Hincke, TSB Board Member. “We are concerned that this information is not available consistently and that accidents will continue to occur as a consequence.”
On 24 October 2013, a CBE Construction Ltd. (Air Cab) Cessna C-185E float plane left Port McNeill, B.C. water aerodrome with a pilot and 2 passengers on board for a charter flight to West Cracroft Island, B.C. At 1140, while maneuvering for landing on water, the aircraft experienced an accelerated aerodynamic stall while being flown at an altitude from which recovery was not possible before it collided with the terrain on a small island in Potts Lagoon, West Cracroft Island. The aircraft was destroyed and the 3 occupants were fatally injured.
The investigation found that several approved modifications (Supplemental Type Certificates or STCs) had been made to the aircraft that resulted in undocumented performance and handling characteristics and that the pilot’s expectation of the aircraft’s performance capabilities may not have been accurate. The investigation also identified a risk if multiple modifications are installed without adequate guidance on how to evaluate and document the effects on aircraft handling and performance. Further, there is an increased risk of stall accidents if advanced stall warning systems, such as angle of attack indicators, are not incorporated on aircraft.
Air Cab has begun emphasizing an awareness of aircraft modifications and their effect on aircraft handling during pilot initial and recurrent training. It is also in the process of implementing a G switch on its aircraft tracking system as a back up to the aircraft’s electronic locator transmitter, and installing a disconnect G switch on its aircraft batteries to reduce the risk of a post-crash fire, in response to other issues identified during the investigation.
In November of 2014, the TSB announced that it would conduct a Safety Issues Investigation into Canadian air taxi operations to understand the risks that persist in this important sector of the aviation industry. The study will engage industry, the regulator and other stakeholders to gain a full understanding of the issues affecting air taxi operations. The Board may make recommendations to address any identified systemic deficiencies.
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.
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For more information:
Transportation Safety Board of Canada
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