@EnderWiggin thanks check my entry out.

Ah, the million dollar question. A couple of tips:
-You want to build an aircraft where the center of mass, thrust and lift points are very close to eachother. Just remeber that mass must be at least slightly forward of lift or the plane will be uncontrollable.
-All lifting and control surfaces must very exaggersted and large. This creates a few issues because lsrge wings don't like to go fast and stay attatched, also large wings slow roll and pitch properties. One solution is stacking smaller wings (i.e. biplane wings and hor-stabs). This allows the aircraft to produce tons of lift and control input without sacrificing agility.
-Keep it simple stupid ;) The more complicated the aircraft is the more trouble the AI will have controlling it. Powerful engines and simple construction, that's the ticket.
-Test, test and test again. Test your aircraft under AI control... a lot... and make small adjustments until you start completing the course. Then test some more while making even smaller adjustments until you see the performance you are looking for.
-Lastly, look at what other people are building and cultivate some ideas. Low hanging fruit all over the site, just make sure you build from scratch or it won't be accepted in a tourny.

I built this for Shark Tooth but I'll be running a my Reef Skimmyr because it's more consistant:
https://www.simpleplanes.com/a/eGmg6O/PY-T44-Reef-Walker

@Flightsonic I trust you that it can. How can I make a better plane for shark tooth?

Try using this (not meant to be advertising) I know for a fact that it can at least get passed the first part