This is just an opinion, but to me your argument for discrimination doesn't wash. You would be asking the court to rule that those who wrote the agreement at the time should have known that the ICAO standard would change, and should have written the agreement to allow for that eventuality. To prove discrimination, you must prove that the victim of the discrimination had no say in the matter, and that the discriminator used a position of power over them that affected them negatively. As the age limit was bargained by two agreeing parties in good faith, that will be a very difficult thing to prove, seeing that those who are claiming discrimination today were either employees of Air Canada at the time of the original agreement, or they joined the company knowing where the boundaries lay at the time, and thus were all parties to that original agreement. Just like there is no mandatory retirement age of 65 yrs today in Canada, there was no mandatory retirement age of 60 yrs for pilots in Canada when ACPA and Air Canada agreed to it. They could have continued to fly, avoiding those places that restricted access to those under 60 (or 65 today). Both sides chose not to do that. The only case you might have for discrimination would be against those countries like the USA who continue to set a finite limit. But seeing as you're not a US citizen, I highly doubt you'd even get a day in court. If you want the age changed, then you should be lobbying your union to change it in the next negotiations.