HALIFAX -- The wreckage of an Air Canada plane including its detached engine, landing gear and a nose cone strewn on a runway of the Halifax airport is expected to be removed within a couple of days, the Transportation Safety Board said Tuesday.

Investigators have concluded their examination of the site where AC Flight 624 crashed at Halifax Stanfield International Airport, the safety board said on its Twitter account.

The board did not return an interview request but tweeted that it has authorized the removal of the plane, which has sat on the runway since it crashed Sunday at about 12:45 a.m. It said it will maintain possession of the aircraft for further examination as it investigates what happened.

The Airbus A320 was flying from Toronto when it touched down 335 metres short of the runway and skidded on its belly for another 335 metres before coming to a stop. All 133 passengers and five crew on board survived, although 25 people were sent to hospital.

One of the pilots underwent minor surgery and one passenger was still in hospital on Tuesday, Air Canada said.

The airport authority in Halifax is also trying to determine why two generators failed to provide backup power to its terminal building after the crash, leaving it without full power until about 2 a.m.

Airport authority spokesman Peter Spurway said generators that supply electricity to the terminal building came on but shut down eight minutes later. A third generator dedicated to the airfield continued running, he said.

Electrical engineers are reviewing what happened, Spurway said.

"It's obviously critical to us because if that Nova Scotia Power feed goes down, we need those generators," he said.

Sasha Irving, a spokeswoman for Nova Scotia Power, said the plane hit a power line that feeds a circuit substation servicing the airport. Damaged power lines are designed to shut down as a protective measure, she said.

The airport has been criticized by passengers about its response to the crash. Spurway said an internal review into that response is underway.

Some passengers said they waited for more than an hour for emergency responders to help them as they stood outside in a snowstorm. The airport has said passengers were waiting up to 50 minutes for help and that firefighters were on scene within 90 seconds.

Spurway said the safety of passengers was top of mind for the authority, noting a 2013 incident in San Francisco where someone survived a plane crash but was killed after being run over by a vehicle on the runway.

"It was the middle of the night, dark and very snowy and windy," said Spurway. "We want to make sure that any time we go out onto the runway in a situation like that, it must be done safely."

The safety board has said when the plane touched down it hit an antenna array. Nav Canada will need to fix the antenna array but that won't prevent planes from using the 3,200-metre runway in "favourable weather conditions" once the runway is operational again, Spurway said.

The board said the plane became airborne again after it first touched down, leaving an extensive field of debris between the antenna and the start of the runway.