Need help w/ planes mod 1.7.3

I am running a legit minecraft game, updated to 1.7.3. i decided to install the planes mod earlier today, and has worked perfectly except for actually flying the planes. I have properly installed everything, but when i hit my default forward move key, the plane does not fly. I have perfect movement outside a plane but inside it doesn't work. it may just be me, but can someone tell me what's wrong?