A friend asked if I would ask.

Passport Cards are good for travel to and from the US to Mexico or Canada, but not by commercial aircraft. 

If you are taking a float plane into Canada to be dropped off, does that constitute a "Commercial Aircraft Flight", where the Passport card would not be valid?

Yes, I know the easy answer is to get a Passport Book.  Just asking what I was asked.

I searched the archives and found a quantity of Passport discussions, but none that spoke to bush plane flights.

Regards,

MossBack