Midair stall blamed for deadly Sask. plane crash
A float plane is seen after a fatal crash along the shoreline of Buss Lake near Southend, Sask. on June 30, 2011.
Published Wednesday, July 11, 2012 2:52PM EDT
Last Updated Wednesday, July 11, 2012 3:56PM EDT
The Transportation Safety Board of Canada has ruled that a floatplane crash that killed five people last June in Saskatchewan was the result of a midair aerodynamic stall.
The TSB said in a report released Wednesday that the aerodynamic stall occurred at a low-altitude, which made it impossible for the plane to recover.
“The aircraft entered an aerodynamic stall,” said TSB Manager Peter Hildebrand. “The stall occurred at an altitude from which recovery was not possible.”
The report also indicated that the weather conditions near Buss Lake on that day may have resulted in fog patches, which could have obscured the shoreline and terrain from the pilot’s view.
The report also said estimates indicated that the aircraft was near its maximum gross weight limit.
On June 30, 2011 a pilot flying a float-equipped de Havilland DHC-2 flew from Southend, Sask. to a remote fishing cabin near Buss Lakes to pick up four passengers.
The four passengers had chartered the plane to take them to a private cabin on Buss Lakes for a fishing holiday.
Shortly after taking off from Buss Lakes, the plane crashed along the shoreline about 5 kilometres southeast of its point of departure. All four passengers plus the pilot died on impact.
The wreckage was found partially submerged in shallow water.
An aerodynamic stall occurs when the airflow over the wings decreases to the point where the wing starts to lose lift. A plane can recover from a stall by increasing airflow over the wings and adding engine power, while the plane descends.
Therefore aerodynamic stalls at low level are considered dangerous because there may be insufficient altitude for a recovery.
In their Aeronautical Information Manual, Transport Canada publishes a warning to pilots about the risk of flying at low altitudes.
“Warning—Intentional low flying is hazardous. Transport Canada advises all pilots that low flying for weather avoidance or operational requirements is a high-risk activity,” says the manual.