I can still remember the feeling of my first Westjet flight, even if I can’t remember the details. I can remember the slightly cramped quarters of the 737-200, I can remember groaning at the jokes told over the intercom, and the flight attendant telling and showing me how to fasten my seatbelt, in case I’d been living under a rock for the past 20 years.

Most of all, I can remember the feeling of how we all – that is to say pilots, crew, and passengers – were in it together. There were no classes of service, no paying extra for better service. We all (roughly) paid the same price to get on the plane, and all got treated the same – that is to say, wonderfully – such a refreshing change from the ‘other guys.’

The news Monday that Onex will pay $5 billion to buy Westjet hit like a bolt from the blue, and unleashed a feeling that can best be described as mourning – even though Westjet isn’t dead – and Onex seems far more likely to build the airline up, than kill it by squeezing out profits.

“Our team takes an entrepreneurial approach to investing,” says Onex on its website. “We seek to work with talented chief executives who want to grow their businesses and embrace the change necessary to make it happen.”

That’s what Westjet has been doing the past 20+ years, embracing change. The airline made its mark trying routes no one else would touch – Edmonton to Victoria springs to mind – and adopting a “use it or lose it” approach to new services. It made the airline more nimble, interesting, less predictable, and dare I say fun.

The West’s aviation market prospered, with 737s zipping back and forth across the landscape, and Westjet grew by leaps and bounds with a deeply loyal following, akin to the loyalty Southwest Airlines inspires among enthusiasts south of the border.

But along the way, something went slightly off kilter. Imperceptibly at first, but now a chasm big enough to know Westjet is no longer the same airline it once ways.

Change in recent years at Westjet, in my opinion, has meant looking more and more like Canadian Airlines International and – gasp – Air Canada. First, Westjet introduced a premium economy section – essentially taking out the middle seat in its 737s and giving a bit more legroom – exactly how Canadian branded its early business class product in the early days.

Then came Westjet Encore, introducing a second aircraft type into the fleet, opening up some markets, but seeing places that once had 737 service, such as Prince George and Grande Prairie, switch to smaller Dash-8 aircraft.

Now, with the 787 Dreamliner, Westjet’s business class product resembles pretty much everyone else’s – lie flat seats across the Atlantic, and 2×2 seating coming in North America. It has even evolved from a point-to-point carrier, to a more big-time hub-and-spoke system concentrated particularly on Calgary and Toronto. In other words, it’s looking a lot like the other guys.

And with a newly-unionized staff (in announcing the sale, Westjet pointedly said Onex has a “history of positive employee relations”), Westjet has turned more corporate and more buttoned-down.

Westjet knows it’s moved away from the low-cost market, that’s why it created its ultra low-cost airline Swoop as a backstop against new entrants drawing away passengers from the cheaper end of the market.

It’s hard to fathom what led Westjet co-founder (and still board chairman) Clive Beddoe to throw in the towel and sell his beloved airline to Onex Corporation in an all-cash $5 billion friendly takeover.

Maybe, at 72, Beddoe simply wants out of the business. Or Onex – which tried to buy and merge Air Canada and Canadian in 1999 – made an offer he couldn’t refuse (and let’s face it, a 67% premium on the share price is a pretty tempting offer).

“Owners care,” Westjet famously advertised emphasizing why its crews were so much friendlier than anyone else’s. That may be true, but over the years, Westjet staff have felt less like owners, and more and more like employees. Working hard, to be sure, but without the same zeal or joie de vivre.

The company still has a legion of fans, to be sure, but to this flyer, the magic has slowly worn off, disappearing under layer after layer of formality – policies and procedures designed to reward premium travellers who paid more for the privilege, and divide them in the front from us in the back. They got the perks, while we were left to watch our satellite tv.

While Westjet looks more and more like Canadian (right down to the Calgary headquarters), there’s no guarantee it will disappear the way Canadian was absorbed by Air Canada. In fact, just the opposite is likely happening, though the days of friendly, folksy service are likely gone forever.

“We’re thrilled to be partnering with WestJetters and continuing this remarkable Canadian success story,” said Tawfiq Popatia, a Managing Director at Onex.

So why does it feel like a death in the family?