You could always point your browser to aircanada.com.

But assuming you want to be able to browse in Airplane Mode or other situations where you have no connection, the only way I can think of offhand is to download the PDF timetable to your computer, then email it to an account you can access from your iPhone. You'll be able to open the PDF attachment from your email. Definitely a brute force solution, but it might do in a pinch. There has to be a more elegant way.