Canadian GST/HST is not supposed to be a business cost to
foreign airlines that are simply landing or departing from Canada
as part of an international flight.
There are a number of GST/HST relief provisions that may be
available to foreign airlines for either not paying the tax in the
first place, or to recover any tax paid in error.
Common GST/HST Relief Provisions for Foreign Airlines
General relief for foreign carriers that are not registered for
GST/HST
GST/HST would not apply to the sale of goods and services to a
foreign airline that is not GST/HST registered and that carries on
a business of transporting passengers or goods to or from Canada or
between places outside Canada by aircraft, where the goods and
services are acquired for consumption, use or resale in the course
of so transporting passengers or goods.