Did you look at that link you posted? It's clearly way our of date, as it lists US Airways as one of the sites. Well, the US Airways site hasn't existed in quite a while now (it got swallowed up in the merger with AA).

So if it's wrong about that, it could wrong about any of the other sites it listed.

This site has current deals:

https://www.paypal.com/us/webapps/mp...s?view=results

and lists CheapAir, Expedia, Hotwire, and OneTravel.

But it's unclear if there are restrictions on what you can use PayPal for on these sites.

I tried dummy booking a flight and couldn't find a PayPal option on Expedia, Hotwire, or OneTravel.