Accident Overview
On a pleasure flight under visual flight rules (VFR), a de Havilland DHC-2 Mk. 1 skiplane, registration C-FIVA and serial number 515, departed from the frozen surface of Lake Adonis, Quebec, with a pilot and five passengers on board. The route was not predetermined, and the flight was expected to last approximately 20 minutes. When the aircraft failed to return, search and rescue (SAR) services were notified. The wreckage was located on a mountainside in a wooded area less than five kilometers from the departure point. The pilot and two passengers suffered fatal injuries. The other three passengers sustained serious injuries and hypothermia. The aircraft was destroyed by the impact but did not catch fire. The five passengers, all from the same family, were originally from Marseille, France.
Investigation Findings
The investigation determined that the pilot was certified and qualified for the flight. Autopsy and toxicological tests found no indication that physiological factors affected the pilot's performance. The aircraft was certified, equipped, and maintained in accordance with existing regulations and approved procedures. Its weight and center of gravity were within the limits specified in the aircraft flight manual. There was no indication of an emergency or mechanical problems prior to impact. Weather conditions were suitable for visual flight.
However, several contributing factors were identified. The pre-flight safety briefing did not inform passengers about the location of survival equipment, preventing them from using sleeping bags to delay hypothermia. Rescue efforts were delayed because the mostly white aircraft blended into the snowy terrain, making it difficult to locate, and the emergency locator transmitter (ELT) antenna was broken, reducing signal range. This increased the survivors' exposure time. Additionally, the ready-to-use weight and balance calculation form was not consistent with the standard; Transport Canada had reported this irregularity in 1992, but no change was made.
Probable Cause
The official probable cause includes the following contributing factors: (1) The aircraft probably stalled with insufficient altitude for the pilot to recover. (2) Conditions were conducive to optical illusions during low-altitude flight over rising terrain. (3) The aircraft was not equipped with a stall warning system, nor was one required by regulation. (4) The pilot's decision to fly at low altitude and likely use cutback power for the climb did not allow for safe obstacle clearance. (5) The inadequate pre-flight safety briefing prevented passengers from accessing survival equipment. (6) Rescue was delayed due to the white aircraft blending into the snow and a broken ELT antenna.