The Air Canada plane that crashed at Halifax Stanfield International Airport in March had no mechanical deficiencies, but the right-side cabin floor was "punctured from below," the Transportation Safety Board says in a preliminary report.

The preliminary report released Tuesday by the board says the right-side cabin floor in rows 31 and 33 of AC624 were punctured. As well, the floor next to the flight attendant fold-down seat near the rear of the cabin was punctured from below. No pieces of the antenna structure penetrated the cockpit.

The report reviews what investigators have done so far, and what work is still left to complete.

Transportation Safety board investigator Doug McEwen outlined how the investigation is proceeding.

"We had a look at the pilots' 72-hour history, interviewed a number of passengers, pilots, flight crews and cabin crew as well as the airport and Nav Canada," he said Tuesday.

Investigators have documentation of the aircraft wreckage and are recreating the accident. "The flight data recorder and cockpit voice recorder are downloaded, and we're in the process of developing an animation for that," McEwen said.

He said there is no clear indication so far of what caused the crash.

"We are still early in the investigation and do not have a conclusion for that yet. There is usually more than one particular contributing factor, for sure."

McEwen said the investigation does not seek to blame individuals.

"We do not use the term 'pilot error.' We do an assessment of the flight crew itself in regards to training, experience and the knowledge they have as well as what they're given for guidance from Air Canada and Airbus."

However, he did say the probe has found out that the flight was configured correctly.

Procedures followed

"Air Canada followed the procedures they had in place. We are looking at the regulations for the particular type of approach they conducted, as well as regulations associated with everything that goes along with the airport itself. The weather at the time was reported to be within the parameters of which Air Canada is allowed to land."

Pretty much everything connected with the accident that occurred is up for review, he said.

"We're looking at what's place today, and if we find a deficiency, or safety deficiency, we will make recommendations to address that."

AC624 crashed in March 2015.

The Air Canada plane that left Toronto and crashed at the Halifax airport suffered heavy damage in the accident in March. (Reuters)

The report does not provide a reason for the crash or attribute blame to the pilots, but says federal investigators will continue to evaluate the training and experience of the pilots.

The March 29 crash of the Airbus A320 caused the plane's landing gear to collapse, ripped off the plane's engine and severed the craft's nose cone after the jet began its skid 335 metres short of a snow-strewn Halifax runway.

The flight had left Toronto en route to Halifax.

Approach-and-landing issues greatest risk

There were 133 passengers and five crew members on board.

The report also said 25 people sustained injuries and were taken to local hospitals, two more than the previously reported 23 injured. No one was critically injured.​

The TSB Watchlist identifies approach-and-landing accidents as one of the issues that "poses the greatest risk to Canada's transportation system."

These accidents include:

  • Runway overruns.
  • Runway excursions.
  • Landings short of the runway.
  • Tail strikes.

The TSB has called on operators, regulators and air navigation service providers to take more action to prevent approach-and-landing accidents.