A Nova Scotia judge has ruled Transport Canada will remain a defendant in a class-action lawsuit filed on behalf of passengers aboard an Air Canada flight that crashed at the Halifax airport last year.

Nova Scotia Supreme Court Justice Denise Boudreau made her decision Tuesday as she certified the lawsuit, meaning it can go ahead.

Other defendants in the case said they would not oppose the certification. They include Air Canada, the Halifax International Airport Authority, NavCanada and Airbus SAS, the French company that builds the Airbus line of jets.

But lawyers for Transport Canada argued the department should be exempt from the lawsuit because it had no direct relationship with the passengers.

Lawyer Ray Wagner, who represents the plaintiffs, argued that as a regulator devoted to passenger safety, Transport Canada owed a duty of care to passengers because it was responsible for reviewing and enforcing safety regulations through the Aeronautics Act.

He said that Transport Canada, as the former owner and operator of the airport, had failed to install an instrument landing system on Runway 05, where the plane crashed.

Plane landed short of the runway

Air Canada Flight 624 crashed in the early hours of March 29, 2015, as it attempted to land at Halifax Stanfield International Airport in poor weather conditions. The Airbus 320 was travelling from Toronto to Halifax, with 133 passengers and five crew members on board.

The plane landed 225 metres short of the airport's main runway. It smashed through an antenna array, bounced on the ground and slid another 570 metres down the runway before coming to a halt.

More than two dozen people were injured. Almost all passengers had to spend about 50 minutes on the tarmac, huddled against a blizzard, before they were taken to an unheated hangar, the lawsuit alleges.

The plane landed 225 metres short of the runway in poor weather. (Reuters)

Boudreau said Tuesday the class action meets the standard of having a reasonable prospect of success.

Transport Canada has no duty of care to Canadian air travellers in general, she ruled. But Boudreau said a claim against Transport Canada as landlord for the airport authority is potentially valid, especially around the installation of an instrument landing system on Runway 05, and this point deserves to be argued in court.

Plaintiffs

Halifax resident Doug Tamlyn was travelling with his wife on the flight. He said he suffered a concussion in the crash and has ongoing dental issues and a shoulder injury.

He also said he and his wife used to fly seven or eight times a year before the accident, but have managed to fly only once since. "There was a lot of anxiety in the landing and taking off. Heart palpitations and this sort of thing. We're not comfortable flying at this point."

Another Halifax resident and passenger, Asher Hodara, said he suffered a mild traumatic brain injury and dental damage.

Malanga Georges Libboy, of Church Point, N.S., said the crash left him with profound psychological stress and pain in his knee, neck and mouth.

Kathleen Carroll-Byrne, of Halifax, said she continues to suffer from anxiety, a loss of concentration and a fear of flying.

None of the allegations in the class action have been proven in court.

Among other things, the plaintiffs allege Air Canada was negligent because the airline did not provide adequate training for its flight crew, particularly when it came to landing in harsh weather.