SOMBA K'E/YELLOWKNIFE - A Canadian North jet slid of the runway Tuesday as it prepared to take off, delaying its take off for an hour and a half and disrupting five other flights.

The Boeing 737 was taxiing down the runway and had just turned around when two wheels slipped off the paved area onto gravel.

"It's a relatively minor occurrence in that it's so rare and it happened during taxiing," said John Green, director of commercial flight operations and charters with Canadian North.

He said the plane wasn't going faster than walking speed and said it would have been more serious if the plane slipped while taking off or landing.

Green said the crew turned the plane off and towed it off the runway in order for maintenance personnel to inspect it. The chartered flight 9410 was heading to Ekati diamond mine. The airline is doing a full investigation into what happened and Green said they'll take added precautions if necessary.

Earl Blacklock, manager of public affairs and communication with the Department of Transportation at Yellowknife's airport, said the incident was unusual.

"Anything that's unusual with an airport is a concerning thing," he said.

The Civil Aviation Daily Occurrence Reporting System report cited the runway was slippery and "braking was ineffective," but Blacklock disputed those conditions.

"The runway was in reasonable shape. It was reported as icy, that wasn't the case as far as our information was concerned," he said.

"The turnaround bay may well have been icy but the runway itself was in excellent condition. It was ready for traffic and had good braking characters."

There was no damage reported and the engines and landing gear were inspected, a report to Transport Canada said. The plane later took off successfully at 10:58 a.m., an hour and a half later than scheduled.

The report also said five planes were delayed up to one hour because of the incident. Blacklock confirmed several other flights were affected.