04/11/2012 01:56 EDT | Updated 06/11/2012 05:12 EDT

Korea flight passengers back to Vancouver after no bomb found

VANCOUVER - About 150 passengers on a Vancouver-to-Korea flight that was diverted to a Vancouver Island military base over a bomb threat have resumed their journey after a 24-hour delay.

Korean Air spokeswoman Penny Pfaelzer said no bomb was found and the Boeing 777 departed Comox, B.C., Wednesday evening for Vancouver, where it would be refuelled before flying to Seoul.

The civilian airport, which is located on the east coast of Vancouver Island and shares a 3,000-metre runway with the Canadian Forces, began processing the passengers and crew at 2 p.m. PT.

Three busloads of people had to be screened, said Christianne Wile, a spokeswoman for the Comox Valley Airport Commission.

The jumbo jet had just departed for Seoul on Tuesday afternoon when an airline call centre in the U.S. received a phone call warning an explosive device was aboard, prompting the plane to make an emergency landing escorted by U.S. fighter jets.

It was the second threatening call to the airline in two days.

"While the investigation is ongoing, I am not aware of any confirmed threat being found," said RCMP Sgt. Rob Vermeulen earlier on Wednesday.

A similar flight was delayed at Vancouver International Airport for two hours on Monday after the airline received a bomb threat. Police boarded the plane and determined that threat was not credible.

"Mostly we are concerned about our passengers' safety, and (keeping) our passengers on schedule," said Korea Air spokesman James Koh, with its Vancouver office, adding he had "no idea" why the airline was getting the threats.

The passengers stayed at two different hotels over night in the town of Comox.

Simon Fraser University securities studies Prof. Andre Gerolymatos said it's hard to know what's going on.

He said the worst case scenario might be that a terrorist organization, such as al-Qaida, would want to use the plane as a weapon and that the airline was just a tool. But he also noted it could be the act of a disgruntled employee or past passenger who was unhappy with service.

"So far they have not found a bomb on the airplane. That means that airplane travel should still be considered a very safe way to go," he said.

But he added: "It hasn't been determined if they're crank calls yet, but it does demonstrate that there is always a possibility of some kind of a threat to Canada."

Two F-15 fighter jets were scrambled from Portland, Ore. to intercept the flight and escort it to the military base, about 180 kilometres northwest of Vancouver.

Tuesday's bomb threat was received about 25 minutes after the flight departed from Vancouver at about 4 p.m. PDT. It landed by about 5:30 p.m.

The airline would have notified ground control, which then would have contacted the Canadian military with the concern going directly to the North American Aerospace Defence Command, said Gerolymatos.

NORAD is an alliance between Canadian and the U.S. that uses airplanes to patrol North America's air safety.

Gerolymatos said there is a base in Cold Lake, Alta., where jets are kept but there must have been some reason Canada's own fleet did not make the interception. Fuelling the two jets would have easily cost the Americans $100,000, he said.

Those costs, along with the alarm caused to the public, means authorities are likely putting in real efforts to determine who made the calls, he said.

"They don't want people to get into a habit of doing this," he said, while suggesting such occurrences are infrequent.

The incident could fuel the ongoing political controversy around whether Canada should equip itself with new F-35 fighter jets, he added.

"I guess if we want to protect our own airspace and not have the Americans to do it, it would make sense to have our own planes."

But Stuart Farson, an adjunct professor who specializes in national security at Simon Fraser University, said the argument around purchasing more fighter jets is irrelevant.

He said it's more likely that deployment strategy — including where planes are located, along with the maintenance, pilots and other support staff — needs to be looked into.

"What we're talking about is replacing what we have with a smaller number of planes," he said. "So that doesn't get us anywhere in terms of dealing with this situation."

The last similar incident of this type in Canada occurred in May 2010, when a pair of CF18 Hornet jets were sent to escort a Vancouver-bound airliner to ground. The Cathay Pacific plane was carrying 283 passengers and 14 crew members on a flight from Hong Kong.

An investigation turned up no threats on the plane.