On the morning of 23 August 2015, a Beaver floatplane, carrying a pilot and five passengers, took off from the waters of Lac Long, near Tadoussac, Quebec, to conduct a sightseeing flight. At the end of the flight, the pilot made a low-altitude turn, likely to give the passengers a better view of some wildlife. The aircraft stalled in a steep turn, descended vertically and struck the ground. The aircraft was destroyed, and the six occupants were fatally injured.
The investigation determined that while the pilot was making a low-altitude turn, an aerodynamic stall occurred, causing the aircraft to enter a spin. An aerodynamic stall occurs when the wings of an aircraft fail to generate enough lift, and—if one wing stalls before the other—a spin ensues. In a spin, the aircraft is rotating and descending vertically. A spin in itself does not necessarily result in an accident, if it happens at sufficient altitude for the pilot to be able to regain control of the aircraft. In this case, although the pilot managed to stop the spin, there was insufficient altitude to prevent the aircraft from hitting the ground.
"In this accident, the aircraft had no stall warning system. Despite the pilot's considerable experience, and even though he was an instructor on this aircraft type, he did not perceive that a stall was imminent when he made the turn," said Kathy Fox, Chair of the TSB. "That is why today the TSB is issuing a recommendation intended to prevent accidents like this one from happening again. We are calling on Transport Canada to require that all commercially operated Beavers be equipped with a stall warning system to alert pilots before their aircraft stalls." There are currently 382 DHC-2s registered in Canada, 223 of which are used in commercial operations. "A stall warning system on board all commercially operated de Havilland DHC-2 aircraft will give pilots and passengers a last defence against this type of loss of control," emphasized Chair Fox.
The investigation also found that the pilot had been regularly performing low-altitude manoeuvres during his sightseeing flights. However, such manoeuvres are not necessary for this type of flight. Given that the aircraft was not equipped with a flight data recorder, the company was not aware of these practices. In 2013, the Board recommended that Transport Canada facilitate the installation of lightweight flight data recorders to help companies monitor how their aircraft are being flown. In addition, following an accident, access to this data would give investigators a better understanding of what happened.
Following the occurrence, the operator, Air Saguenay, has increased oversight of its sightseeing flights and made adjustments to its training.
See the investigation page for more information.