The agency in charge of investigating a plane crash that killed two men last year says hypoxia, or in-flight oxygen deprivation, likely resulted in the incident.
A Piper PA-31 aircraft was conducting survey activities in the Kananaskis region for about two hours on August 1, 2018.
The pilot was beginning to return to the Springbank Airport when the right engine suddenly began running at a lower power than the left engine. About a minute and a half later, the aircraft lost control and crashed into the summit of Mount Rae.
The bodies of the two men were recovered from the scene. Their identities have not been released.
The Transportation Safety Board released its final report on Thursday and determined both occupants likely passed out mid-flight because of a lack of oxygen in the cabin.
Officials say an investigation discovered that while the plane possessed a portable oxygen system, the pilot was not continuously using oxygen despite the regulation to do so while the aircraft was above 15,000 feet.
As a result, both the pilot and passenger would have experienced performance degradations that were likely imperceptible to either one of the individuals. The symptoms would also be very difficult to identify if flight crews lack practical hypoxia training.
The TSB also says the plane did not possess an in-flight data recorder or cockpit voice recorder but those instruments were not required for that type of aircraft. It did, however, possess a flight data monitoring system, including a camera, that provided officials with critical information about the incident.
Full details of the TSB investigation can be found online.
