I've been looking into some ticket prices and I just noticed that if you book a return ticket from Toronto to Europe, you pay a $30 NavCan Surcharge, but if you book a return ticket from Europe to Toronto, this surcharge promptly disappears.

Now, I admit I am not a rocket scientist, but this appears to defy logic. A visitor coming to Canada from Europe will spend as much time in Canadian Airspace as someone travelling to Europe from Canada. The sequence of events is reversed, but there is still one arrival and one departure from a Canadian airport. The amount of time you spend in the air is the same. Why are Canadian residents being specifically singled out?

Can anyone direct me to literature or information about why this is the case? Does the surcharge go to Air Canada (like the fuel surcharge) or does it go to NavCan directly?