Lorne Perreault died in the crash in what the TSB investigation said was supposed to be a two-hour training flight on Aug. 6, 2013.
The Cessna 172 disappeared from radar shortly after climbing to 2,700 metres. Perreault's body and the aircraft were found the next day.
"It is possible that the pilot had begun recovery from a spiral dive and achieved a wings-level attitude, but did not have enough altitude to fully recover," said the report released Tuesday.
"During impact, the aircraft's cabin was severely compromised, making this accident unsurvivable."
When the aircraft did not return at the scheduled time, the instructor, who was supervising the flight, notified search and rescue services and two employees of TylAir Aviation started an air search in their private aircraft, the report said.
Investigators said the crash happened about an hour and a half into the flight and that the plane was not carrying an emergency locator, which resulted in a delay in finding the pilot and wreckage.
While the board noted the locator was not required because the flight was not intended to go beyond 40 nautical kilometres from Kamloops, it said the removal of the instrument should have been documented.
Lead investigator Glen Friesen said there is every reason to believe that the teen was ready to fly solo.
"He demonstrated the ability to recover from these types of manoeuvres. And pilots have to go solo at some point and the instructor being comfortable that he was at that point that he could safely handle the aircraft. So we're not exactly sure what happened or why he didn't recover." (CFJC, The Canadian Press)