A Calgary man is facing charges after a bizarre attack on the STARS air ambulance.

A man drove through the security fencing at the Peter Lougheed Centre Sunday afternoon.

The vehicle he was driving came within five metres of a STARS helicopter which was preparing for takeoff.

One of the pilots jumped out of the chopper and was able to stop the man from coming any closer.

He tells CTV that his training took over to help prevent the incident from turning into a tragedy.

Hospital security held the man until police arrived.

One of the security officers was hit in the face during the altercation.The ambulance did not have any patients on-board at the time of the incident.

Police say they don't have a motive for the attack on the chopper but there are reports that someone at the hospital recognized the man and he was discovered to have prescription drugs in his possession.

Trevor Todd Reilander, 31, is facing charges of endangering the safety of an aircraft, dangerous operation of a motor vehicle and assault.

Transport Canada is also investigating the incident.

STARS has five helicopters and will be adding a sixth to the fleet this spring at a cost of more than 12 million dollars.

More than half of funding for the service comes from the STARS annual lottery.

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