What happened
On a dark evening in Ontario, a Robinson R22 Alpha helicopter, registration N97CP, departed Toronto City Centre Airport for a routine 20-minute flight to a private helipad in Norval. During the flight, radar data showed the aircraft climbing to approximately 1,800 feet above sea level before entering a series of erratic maneuvers, including a tight left climbing turn followed by a rapid descent.
Shortly before 20:00 EDT, the helicopter pitched nose-down and struck a treed, swampy area near Huttonville, within the city of Brampton. The impact, which occurred at a 50-degree angle, triggered a post-crash fire that partially destroyed the aircraft. The pilot sustained one fatality.
The investigation
Investigators examined the wreckage and found no evidence of mechanical failure or system malfunction prior to the impact. However, the engine was not running at the time of the crash, and the mixture control knob was found in the idle cut-off position.
Two primary scenarios were analyzed regarding the engine shutdown. The first involved the pilot attempting to apply carburetor heat to combat potential icing, which led to the accidental movement of the mixture control. The second focused on the lack of a protective plastic guard, which is required by the manufacturer to be placed over the mixture knob to prevent such errors. The investigation also noted that the aircraft was being operated in Canada without required Canadian registration or valid liability insurance.
Findings
- The pilot likely inadvertently pulled the mixture control to the idle cut-off position while attempting to activate carburetor heat.
- The inadvertent engine shutdown was made possible because the required plastic guard had likely not been installed over the mixture control knob.
- Following the loss of engine power, the rotor RPM decayed, leading to a loss of control.
- The pilot likely experienced spatial disorientation due to the lack of visual references in the dark, misty conditions, which prevented the maintenance of controlled flight.