Kristin Radtke was stunned when Air Canada rejected her compensation request for a six-hour flight delay when travelling from Edmonton to Montreal on Christmas Day.

She thought her case was a slam-dunk because her fiancé and travel partner had already filed a claim on Jan. 1 for the same flight — and received $700. But when Radtke filed her claim almost two weeks later, Air Canada replied that her trip delay was due to a safety-related "technical fault" and didn't warrant compensation.

"I'm just baffled," said Radtke, who lives in Edmonton. "We're two identical passengers."

She's one of a half-dozen Air Canada passengers CBC News interviewed who question why they were denied compensation for delayed flights which took off after Dec. 15.

The federal government introduced new regulations on Dec. 15, mandating that large airlines — such as Air Canada and WestJet — must pay up to $1,000 in compensation for a flight delay or cancellation that is within the airline's control and not safety-related.

New regulations introduced on Dec. 15 require that large airlines must pay up to $1,000 in compensation for a flight delay or cancellation that is within the airline's control and not safety-related. (CBC)

Before the new rules took effect, some industry experts expressed concern that airlines might try to fudge the reason for a flight delay to avoid paying compensation.

Air Canada spokesperson Peter Fitzpatrick told CBC News the airline's policy is to abide by the new regulations. He said he couldn't comment on the three customer cases detailed in this story because they're "under appeal."

Which reason is it?

Radtke believes she deserves compensation not only because her fiancé got cash, but also because when the couple's original flight was cancelled and had to be rebooked, Air Canada sent a text alert stating the culprit was "crew constraints."

According to the new regulations, flight delays caused by staffing issues are generally considered within an airline's control and eligible for compensation. But when Radtke filed her claim, she was told her trip delay was caused instead by a safety-related technical issue.

"It's either crew constraints or it isn't," she said. "How can the reason for a flight cancellation change?"

Radtke filed a complaint with Air Canada on Jan. 22. Despite repeated calls and emails to the airline, she's still waiting for a response, she said.

"We kind of feel like we're being stonewalled. It's just immensely frustrating."

Hey <a href="https://twitter.com/AirCanada?ref_src=twsrc%5Etfw">@AirCanada</a> you’ve denied our compensation request saying the delay was weather related, but we have your original flight notification texts saying delay was due to technical difficulties. Now your customer service has stopped replying to emails. What do you suggest now?? —@Maturin19 <a href="https://twitter.com/AirCanada?ref_src=twsrc%5Etfw">@AirCanada</a> how are scheduling issues out of your control for your flights? Where does your accountability start? —@mnbanner

Air Canada passenger Melissa Nickerson is also unhappy with the airline's decision in her case. She and her husband were travelling from Chicago home to Calgary on Dec. 30 when their flight was cancelled and rebooked, resulting in a delay of more than 13 hours.

According to the new rules, large airlines must pay passengers $1,000 for applicable flight delays longer than nine hours.

When their flight was cancelled, Nickerson and her husband got meal vouchers which stated the cancellation was "controllable." Air Canada also sent a text alert blaming the mishap on "crew constraints."

But when Nickerson filed for compensation, the airline rejected her claim, stating that her trip delay was instead due to a safety-related "technical fault."

Melissa Nickerson received this message from Air Canada when her flight was cancelled. (Supplied by Melissa Nickerson)

"I was disappointed," said Nickerson. "They were quoting a delay reason that had nothing to do with our flight."

She filed a complaint with Air Canada on Jan. 22 and is still waiting for a response.

"I was expecting this should be an easy process and it's cut and dried that I'd be getting compensation," she said.

'It's vague'

Jennifer Janssen was so upset with the explanation Air Canada gave her for a delayed flight, she filed a suit against the airline last month in small claims court.

"I was like, 'This doesn't seem right,'" said Janssen, who lives in Hamilton.

On Jan. 1, her flight from Gander, N.L., to Toronto was delayed by more than nine hours due to "crew availability," according to Air Canada.

But when she filed for compensation for herself and her travel partner, the airline turned Janssen down, stating the delay was due to safety-related "scheduling issues."

"It's vague and it leaves a lot open to interpretation," she said. "They're leaving information out somewhere."

Jennifer Janssen and her boyfriend, Tyson Collins, believe they deserve compensation for a recent delayed Air Canada flight from Gander, N.L., to Toronto. (Submitted by Jennifer Janssen)

Canadian Automobile Association spokesperson Ian Jack said it's hard to know if an airline's explanation is valid when it's lacking in detail.

"People do deserve a cogent, logical response — if there is one. Otherwise the carriers are just going to see a lot of complaints going to the [Canadian Transportation Agency]," said Jack, whose organization took part in the consultation process for the new regulations.

WestJet passenger Paul Walker has already filed a complaint with the CTA following a three-hour delay on a Jan. 16 flight from Winnipeg to Edmonton.

Walker had expected $400 for the delay, as laid out in the new rules. However, WestJet denied his compensation request, stating the culprit was "flight crew member delays from previous day events and outside of WestJet's control."

Similar to other passengers, Walker finds the explanation unsatisfactory.

"It seems suspicious," said Walker who lives in Winnipeg. "The reason they're still giving is that it's a flight crew delay, which is actually within their control."

Paul Walker, right, and colleague Ryan Murray flew from Winnipeg to Edmonton to attend a conference. Their WestJet flight was delayed by three hours but the airline said the delay doesn't warrant compensation. (Submitted by Paul Walker)

WestJet told CBC News it follows the new regulations and declined to comment on Walker's case.

The CTA said in an email that when passengers file a complaint about a flight delay, the airline involved will have to demonstrate why the delay doesn't warrant compensation.

"If it were discovered that an airline had misrepresented the cause of a delay to the CTA, this would be taken very seriously."