WestJet is at the centre of a federal transportation inquiry after an Edmonton couple was bumped off a flight last month without being informed.

The federal tribunal tasked with overseeing air transportation says the inquiry will examine whether parts of WestJet policies are "just and reasonable" and whether they align with the new Air Passenger Protection Regulations (APPR), the Canadian Transportation Agency said in a news release Friday.

The inquiry is the first since the agency started enforcing parts of the regulations on July 15, says industry watchdog Gabor Lukacs.

"We have been very concerned about this type of situation," Lukacs said.

Chelsea Williamson and her husband spent more than a year planning a two-week backpacking trip through Italy for their honeymoon.

The couple checked in to their flights online the day before departure without issue, Williamson told CBC News. On July 22, they arrived at the Edmonton International Airport with carry-on backpacks and breezed through security.

But when they got to the boarding gate, tickets in hand, the agent told them they didn't have seats on the flight, Williamson said. The gate agent said WestJet had downsized the aircraft the night before and rebooked the couple on a flight leaving five hours later, she said.

The Canadian Transportation Agency says its inquiry will look at whether WestJet policies align with new Air Passenger Protection Regulations. (Canadian Press)

The original flight left on time. Williamson and her husband arrived in Venice eight hours later than expected.

"It's extremely disappointing," she said.

"It took away a good chunk of time for us in Venice and unfortunately, we had only planned to stay two nights."

'It's just kind of unfathomable'

WestJet didn't notify the couple beforehand, Williamson said, and neither did their third-party booking agent, Air Miles. She said an Air Miles representative told her WestJet never alerted the company to itinerary changes.

"In what other area can a consumer buy something and then have the retailer or contractor or whomever change it on them without consulting and receiving approval from the customer first?" Williamson said.

"It's just kind of unfathomable."

Williamson and her husband on their honeymoon in Italy. The couple lost a day of sightseeing after they were bumped from their WestJet flight leaving Edmonton. (Submitted by Chelsea Williamson)

Williamson said her situation amounts to denied boarding: she arrived at the gate with a ticket for a flight and was told the airline could not accommodate her on the plane.

Under the new federal regulations, passengers are entitled to $1,800 for a six- to nine-hour delay to their final destination in cases of denied boarding.

But WestJet has a different interpretation — an interpretation Williamson said has never been communicated clearly.

Delay, not denied boarding, WestJet says

In direct messages with the WestJet Twitter account, an agent told Williamson her itinerary had been changed because Delta, a partner airline, had overbooked the flight. Williamson was told her third-party travel agent should have notified her of the changes to the itinerary. WestJet's website states the company doesn't overbook flights.

A screenshot of an exchange between Williamson and the official WestJet Twitter account. An agent says Williamson's reservation was changed because Delta oversold the WestJet flight. (Chelsea Williamson)

Then, in later email exchanges with Williamson, the company said the situation amounted to a delay for an "operational change," but offered no further explanation.

Williamson could claim $400 for the delay under the new regulations — except those provisions don't come into force until mid-December.

As a result, WestJet told Williamson she wasn't entitled to compensation, but offered her a $125 courtesy voucher.

"I didn't feel that was acceptable," she said.

Complaint prompts federal inquiry

Williamson took her story to the Huffington Post and filed a complaint with the Canadian Transportation Agency.

"The information in the complaint and [news] report raises the possibility that WestJet's tariff is being interpreted and applied in a manner inconsistent with the denied boarding provisions of the APPR," the agency said in the Friday news release.

An airline tariff is a mandatory contract between an air carrier and its passengers that sets out both their rights and obligations.

The transportation agency and WestJet declined interviews with CBC News.

In an emailed response, a WestJet spokesperson said the company is co-operating with the agency, and is declining to comment while the investigation is ongoing.

Williamson said the agency's inquiry validates her complaint. She said she hopes the investigation will expose any issues in WestJet's policies, as well as any gaps in the new regulations.

New regulations narrow passenger rights, advocate says

Lukacs, the airline passengers advocate, said the issue may boil down to the wording of the regulations.

The new regulations actually narrow, rather than embolden, passenger rights for denied boarding, said Lukacs, founder of watchdog group Air Passenger Rights.

To claim denied boarding under the new rules, a passenger has to "hold a confirmed reservation" for the flight.

We flagged those issues for a very long time in advance ⁠— that this would be a problem ⁠— and they just weren't listening.​​ - Gabor Lukacs, passenger rights advocate

WestJet could argue that Williamson no longer had a confirmed reservation when she arrived at the gate, since the company changed her itinerary beforehand, Lukacs said.

"Under the new rules, even in this extreme case, I'm not convinced that WestJet has done something wrong legally. Morally, clearly this is wrong because they're dodging the purpose of the regulation," Lukacs said.

"The purpose is to ensure passengers who are denied boarding get compensation, and they're clearly dodging that. So that part is really a no-brainer."

Airline passenger advocate Gabor Lukacs says the federal government's new passenger regulations may provide a loophole for airlines. (Andrew Vaughan/Canadian Press)

The Canadian Transportation Agency ruled in 2016 that airlines are still on the hook for denied boarding compensation if they bump a passenger off a flight because of limited seats, even if they notify and rebook the passenger well ahead of time.

In those cases, a passenger would not have to present themselves at the boarding gate. But under the new definition of denied boarding, a person has to be present at the gate.

"We flagged those issues for a very long time in advance ⁠— that this would be a problem ⁠— and they just weren't listening," Lukacs said.

He's skeptical the inquiry will lead to any substantial changes, calling it a publicity stunt.

"I think it's well beyond the scope of the inquiry," he said. "And I don't think there's the political appetite."