guest666

This would be possible if there was a guarantee that this very passport wouldn't be scanned and its NPR stored in all imaginable databases. It is possible to just show up at the check-in without eTA in advance (in some cases people get eTA minutes before boarding is closed), but what exactly happens with that Canadian passport at the check-in is not at all clear. Do they just look at it and say "oh ok, you're good to go" or do they enter the data into the eTA interface to which only CBPA has access... or rebook the whole ticket with that Canadian passport and thus feed it into the Schengen database. Unfortunately, no amount of googling gave any answers. It very well may be that the electronic clearance system that the airline personnel enters it into is an internal Canadian business that doesn't leak anywhere else (eTA would actually be exactly that - a strictly Canadian assessment done through the government website that is a black box for external agents). The people who know the internal mechanics of what happens at the check-in would be worth their weight in gold, but they're not around.