A preliminary report by the Transportation Safety Board says a damaged tail rotor is likely what caused a Hydro One helicopter to crash near Tweed last week, killing four people.
During its initial investigation the TSB says it found evidence that an equipment bag, being transported on a platform attached to the chopper, came loose and hit the tail rotor, while the pilot was carrying three linemen from a hydro tower, to a staging area a short way away.
When the pilot attempted to land, he lost control and all three workers were thrown from the helicopter, which crashed nearby.
The report says weather was not a factor and that two of three passengers’ seatbelts were found to be unfastened.
The chopper was not equipped with a cockpit voice recorder or flight data recorder, but did have a GPS unit, which investigators are using to find out more about the crash.
The TSB is now reminding helicopter operators to secure all cargo and all passengers to wear seatbelts.