Accident
On July 31, 2007, at approximately 1125 eastern daylight time, a Cessna U206F floatplane (registration C-FMGP, serial number U20602839) operated by Aviation Mauricie departed from Pasteur Lake, Quebec, on a visual flight rules flight with one pilot, one student pilot, and one passenger aboard. After takeoff, the aircraft flew at low altitude over the water for a few seconds. At about 30 feet above the lake surface, it made a 90° left turn and headed directly toward the departure wharf where the owners were. At approximately 100 feet above the wharf, the aircraft was seen in a nose-up attitude and appeared unstable. Shortly after, the right wing pointed toward the ground, and the aircraft pitched nose down and crashed into trees about 300 feet farther south.
A witness rushed to the crash site and saw smoke coming from the wreckage. Several minutes later, flames appeared at the right wing root. The fire could not be controlled with a fire extinguisher and spread to the cabin and the rest of the aircraft. The three occupants sustained fatal injuries.
Flight History
Earlier that morning, at approximately 0940, the floatplane had taken off from Tortue Lake, Quebec, Aviation Mauricie's main base. The planned flight was a return trip with stops at Pasteur Lake and Taureau Reservoir. At 1020, the aircraft docked at a wharf on the eastern shore of Pasteur Lake, where the occupants spent time with the owner of the premises, a friend of the pilot.
Investigation
Examination of the wreckage revealed no deficiencies, engine failure, or aircraft system failure. There was no indication of any emergency situation or aircraft problems before impact. The wreckage damage was consistent with a loss of control following a stall. The aircraft stalled at about 100 feet above the ground, an altitude insufficient for recovery.
There was no evidence that incapacitation affected the pilot's or passenger's performance. An autopsy on the front seat passenger revealed coronary heart disease but no recent indications of thrombosis or infarction.
The takeoff flight path chosen was shorter than the usual path used by local pilots, resulting in the aircraft being not as high over obstacles as expected. The investigation could not determine why the pilot did not follow the suggested takeoff path.
After becoming airborne, the aircraft should have made a 60° left turn toward a saddle at the south end of the lake to continue the turn over the lowest terrain. Instead, it continued turning until facing the departure wharf, over which it flew shortly after. The investigation considered it reasonable that the pilot flying performed this maneuver to fly over the wharf.
The left turn put the aircraft in tailwind conditions at low altitude, heading toward higher terrain. This may have caused the pilot flying to increase the aircraft's attitude, inadvertently decreasing speed. The stall could be due to a combination of factors reducing the margin between aircraft speed and stall speed, in conditions conducive to optical illusions from drift and flying toward rising terrain.
After turning into the tailwind, ground speed increased, reducing climb angle and extending the climb path. The floatplane flew over the wharf at a height insufficient to clear the terrain. It is possible that lack of familiarity with the area led to underestimating distances and wind effects.
It could not be determined who was at the controls. Possibilities included the student pilot (since it was a training flight and the student sat in the usual pilot's seat) or the pilot-in-command (since the aircraft flew toward the wharf where his friends were). If the student was at the controls, he might have decided to fly over the wharf without the pilot's consent, and the pilot might not have reacted in time. As the pilot was not an instructor, he was less likely to rapidly recognize unsafe practices.
The collision with trees caused a fuel leak in the right tank and damaged the electrical system. The first flames at the right wing root suggested ignition of fuel in that tank. Several minutes were needed to create a flammable gas mixture.
Probable Cause
The aircraft stalled in conditions conducive to optical illusions created by drift and resulting from flying towards rising terrain; there was insufficient altitude available to effect a recovery.