It has been awhile since I last purchased a flight pass. I was always impressed with the flexibility to cancel a flight for no charge. As I went looking today, I noticed that Air Canada has added change fees to flight pass bookings for new passes.

The same day change seems to vary from pass to pass, but the $50 seems to be same across many different passes. Changes and Cancellations

• Flight credit booking changes are subject to availability; a $50 CAD fee per direction, plus taxes, applies to booking changes and cancellations.
• Same-day changes done either at the airport with an agent or at a self-service kiosk are subject to availability. A $100 CAD fee per direction, plus taxes, applies.