The Transportation Safety Board of Canada says deteriorating weather and departure under conditions of near darkness in northern Ontario, led to the crash of a helicopter owned by Wingham-based Apex Helicopters.
The crash happened on September 8, 2015 and killed two people, Ken Mielke, 41, of Kitchener and Jeremie Belanger, 24, of Kapuskasing.
After leaving a camp on Horwood Lake and bound for the Foleyet Timber Camp 100 kilometres southwest of Timmins, the helicopter struck trees on elevated terrain and was destroyed by the impact.
The helicopter was equipped with an emergency locator transmitter that activated upon impact, but the antenna had broken off during the crash, and the aircraft was not reported missing until the following day.
The TSB says the helicopter was not equipped for flying at night or in instrument conditions, and the pilot was not certified for conducting such operations.
In the TSB report released Tuesday, investigators said it is likely that the pilot was unable to determine the helicopter's height above the forest canopy or notice the rising terrain ahead before striking the trees.