SOMBA K'E/YELLOWKNIFE
Ash spewing from Alaska's Mount Pavlof volcano has prompted airlines to cancel flights to and from the city, leaving Yellowknife-bound passengers stranded at airports and at least one NWT mine site.

Volcanic ash, which can cause engine failure if sucked into air intakes of aircraft, began pouring out of Alaska's Mount Pavlof volcano on Sunday afternoon and caused numerous flight cancellations in the territory on Tuesday and Wednesday. - Colt Snapp photo

Ekati employee Chris Holloway told Yellowknifer by e-mail mine workers waiting to fly back to Yellowknife learned they would be spending a little more time at the mine than planned, around 5 p.m. on Tuesday, when they were told flights in and out of the mine site were cancelled because of the ash.

"We were just notified that all flights into and out of Ekati have been cancelled," Holloway wrote on Tuesday while waiting at the mine located about 300 kilometres northeast of the city. "I don't know when we will get out," he wrote.

On Wednesday, Holloway stated approximately 400 Ekati employees are affected.

"Employees going out, employees coming in and some contractors brought in for a scheduled two-day shut down (are affected)," wrote Holloway, adding the skies were looking clear on Wednesday. "I am currently scheduled to fly out this afternoon."

Yellowknifer attempted to confirm with Dominion Diamond Corporation how many people were affected by the flight cancellations. Instead, the newspaper was provided an e-mailed statement from CEO Brendan Bell confirming some flights to and from Ekati have been affected.

"Passengers have been re-booked on other flights," the statement read. "Accommodation was provided for those who needed it."

Bell stated chartered flights to the mine site is provided by First Air, Air Tindi and Summit Air.

First Air issued a news release announcing flight cancellations on Tuesday and updated it Wednesday morning, stating flights between the city and Hay River would be cancelled Wednesday as well. A total of 20 First Air flights were cancelled Wednesday, and 12 delayed. The company stated it expected to be fully operational by Wednesday afternoon.

"Other flights are expected to operate but at delayed timings to allow for the ash cloud to move away," states the release.

A number of the company's flights across the territory and Nunavut were cancelled Tuesday but rescheduled Wednesday, according to the release.

Yellowknife Airport manager Lee Stroman said he has not received enough information about the Alaskan ash cloud which would help him estimate when flights might resume. On Wednesday morning, he said volcanic ash is not currently present in the air around the capital's airport.

"It isn't all making sense to me just yet," he said. "I'm not quite getting the whole ash story."

According to a U.S. Geological Survey news release published Monday night, the intensity of the eruption which began on Sunday afternoon had "declined significantly."

Airlines realized the dangers posed to aircraft by volcanic output when a British Airways jet suffered engine failure in all four of its engines in 1982, after flying through an ash cloud produced by the erupting Mount Galunggung - located approximately 180 kilometres southeast of Jakarta, Indonesia. The reason for the failure was not apparent to aircraft controllers at the time, who diverted the flight to Jakarta. When the jet glided out of the ash cloud the crew was able to restart the engines, allowing the plane to land safely in Jakarta.

Bert van der Stege, vice-president commercial for First Air, wrote in an e-mail that flying in an ash cloud is like flying in a cloud of small rocks.

"(The rocks) end up acting like sandpaper on the aircraft," he stated. "Flying through ash can scratch the windows to the point that you cannot see through them. It can erode forward facing surfaces, including the wings, propellers and antennas, can plug various tubes that gather air pressure data to display speeds and can cause aircraft to lose radio contact with other aircraft and the ground."

The ash can cause serious problems for aircraft engines, stated van der Stege.

"It wears down the blades and can also plug holes, nozzles and jets," he wrote.

High temperatures in working engines can cause the ash to melt and cover the engine with a layer of glass, he wrote.

"Between the internal erosion and this coating of glass, this is what can lead to the engine to fail," stated van der Stege. "Even if the engine doesn't get to the point of failure, the damage that is done is permanent."

He stated that radar does not pick up an ash cloud, so the only way pilots will know they're flying into one is if they see it.

"Spotting it visually obviously can't happen if you're flying in clouds," he wrote. "You also can't see it at night - which was our issue last night."

The ash cloud has caused numerous flight cancellations as it moves across the continent.

Ash in the upper atmosphere prompted WestJet to cancel some morning flights heading to Edmonton, Calgary and Toronto from Regina on Tuesday and dozens of passengers had to be rebooked the following day. Alaska Airlines cancelled a total of 41 flights on Monday and more than 3,000 customers were affected.

Canadian North spokesperson Kelly Lewis stated the airline cautioned passengers flying on Wednesday that they could experience delays or cancellations due to the ash, but no related advisories were posted on Thursday. Air Canada spokesperson Debra Williams stated the company's flights to and from the city were not affected. WestJet spokesperson Lauren Stewart stated one flight into Yellowknife was delayed. Allan Moore, chief operating officer for Air North, said one Tuesday flight was cancelled as a precaution.

Spokespeople for Summit Air and Northwestern Air did not respond to requests for comment before press time.

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