Lots of good advice above. Evelake's settings are a good start, though I have a few suggestions geared towards your first time out shooting props. I use a 50D with a 100-400, and also a 'walkaround' lens for statics and wide shots.
Unless you have lots of panning practice (eg, birds in flight or motorsports) for props I suggest you start at 1/320 and then try 1/250. This will up your keeper rate, and will still give you enough prop blur so the plane is flying, and not 'levitating'.
Use AI Servo and the center focus point, to help lock onto the plane and not things in the background.
JWOL mentions ISO 100 in his blog. I use this lots for props so I can slow the shutter down.
I use Camera User Settings with C1 set up for props in TV mode with my other settings, and C2 set up in AV and auto iso for jets and other things.
Hope this helps. Have fun, and I hope you get some great shots.
(This is my first post. I've been following this forum for a few years and have learned a ton from it. Thought it was time I started giving something back!)