News release

Complex mountain flying conditions caused an unrecoverable aerodynamic stall in July 2011 crash in Harrison Lake, British Columbia

Richmond, British Columbia, 6 November 2013 – The Transportation Safety Board of Canada (TSB) today released its investigation report (A11P0106) into the July 2011 collision with terrain of a Cessna 152 near Harrison Lake, British Columbia.

On 5 July 2011, a Pacific Flying Club Cessna 152, with a flight instructor and student pilot on board, departed Boundary Bay, British Columbia, for a mountain training flight. An hour and a half after departure, the aircraft collided with terrain about 10 nautical miles west of Harrison Lake. The aircraft was destroyed by impact forces, and both occupants of the aircraft died.

The investigation found that the accident was likely caused by an aerodynamic stall while attempting a turn at an altitude from which the pilots could not recover before colliding with the mountain. Without proper training in mountain flying techniques, pilots and passengers are exposed to increased risk of collision with terrain due to the complex nature of mountain flying.

Following the occurrence, Pacific Flying Club implemented safety actions. Among them are:

  • The creation of a formal, regimented Mountain Flying Training Syllabus, and training for all instructors that includes defined procedures for canyon turns, minimum altitudes, mandatory routing, and standard operating procedures.
  • Modifications to the Mountain Flying Program, including a ground school prior to flight, prescribed new routing, and the use of flight training devices to enhance pilot awareness of hazards.


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.

For more information, contact:
Transportation Safety Board of Canada
Media Relations
Telephone: 819-994-8053
Email: media@tsb.gc.ca