Would you rather live in a country with a high tech sector or one that supplies raw materials to countries who have high tech sectors? What sort of employment generates more wealth? Seriously consider that every sophisticated economy on this planet uses tax revenues to support activities that produce much greater tax revenues (chopping down trees does not). It's like providing public education. You may whine and moan that your precious hoard is being blown teaching children how to read and write but if you lived in one of those dysfunctional shyteholes where children do not get that training, you would not have a hoard. You want your to be a third world shytehole because you want to board the Howard that you accumulated living in a developed sophisticated place. Support high tech activities. We will get our investment back in a big way.
don't get me wrong. I'd be all for eliminating all business taxes and then introducing a 1/3 tax on the net profits of the following four categories of businesses:
1. non-renewable-resource extraction businesses,
2. animal-husbandry businesses,
4. addictive products and services (e.g. tobacco, alcohol, gambling, etc.), and
5. other legitimately undesirable businesses.
The tax break to all other businesses would serve as a natural 'subsidy to desirable businesses.
I would advise against a trade war, but if we must have one, then I'd say impose an export tariff of X USD / kg and X USD / kw to the US. This would hurt our raw-resources industries the most and our high-tech industries the least, essentially causing a kind of reverse dutch disease by reducing Canada's exports of raw materials and so force the value of the CAD down to increase the exports of finished industrial goods.
Again, I'd advise not going down that route except if necessary as part of an all-out trade war with the US.
If Canadian raw materials to the US go up in price and the US needs to import them from somewhere, then that will also push up the price of Us manufactured goods to the world due to the overhead cost in raw resources.
And in the age of environmental stewardship, why would we want to subsidize airplane companies and so indirectly airlines and by extension air travelers who for the most part represent the middle-to-upper classes?
One would think we'd rather subsidize telecommuting technologies (like computers, smartphones, and tablets) and bicycles, not fuel-guzzling airlines. Government needs to come back down to earth.
Another thing. When Canadian taxpayers subsidize an airplane company, we're also subsidizing foreign airlines all around the world that buy that plane. Ridiculous.
Trump also shot the US in the foot given that many Bombardier parts are built in the US. Buy the way, many Boeing parts are built in Canada too.
I vaguely recall Trump using the phrase "American first" So (to me) this doesn't come as a surprise! 
