Dauntae,
You can get the full rules on the RCCA site, www.rccombat.com. Look under "start combat". The short version is that the prototype airplane had to have fixed, forward firing guns, and have been built between 1935 - 1955 (though I might have the exact dates wrong, so double check if you aren't doing something close to ww2).

The model has to be 1/12th scale, with any (or all) of the model scaled up or down up to 10%. That means you can scale the wing span and chord up 10%, but leave the fuse alone, or scale the fuse down a bit from 1/12th if you want. (A lot of guys, myself included, don't like this, and think it's the wrong reading of the rules, but the tech committee ruling allows this, so that's how it goes). In theory, the outline can be judged at 15ft, and should be recongnizeable as the correct plane. You should have a 3-view handy in case you are questioned. Though I've never actually seen a plane challenged at a contest. It's common practice to ommit things like radiators and such to make the planes easier to build. You can increase the tip chord to 1/12ths cale +10%, but leave the root chord at 1/12th, though it would look silly. But increasing the tip cord beyond that wouldn't be legal technically.

Colors and markings should be something that the actual airplane could have worn, though modeling a particular example is not required. You can make up squadron or unit markings all you want, but if you pick a plane where every one of them was done in brown an green camo, then you need to paint in brown and green camo (or something close anyway. No one is checking paint chips here). As with the outline, the colors aren't usually juged that closely. Oh, and you can mark the bottom of the plane with non-scale markings to make it easier to see in the sky for safety.

There is a max weight of 2.5lbs dry. Engine has to be .26 or smaller. Muffler can be anything as long as it's shorter than 8". So, no full length tuned pipes, but 1/4 wave pipes like the mousse can or ultrathrust are legal.


Speedster,
You might think the TT Pro would be right up there with the OS. But it's not. Feel free to show up at any contest with a TT powered plane though. I'll have to throttle down to catch you, but that's not a problem .

Seriously, unless TT changed something, that .25 just doesn't have the power. Neither does the Mag .25 or the GMS .25.

For reference, on 15% Omega fuel, my webra .25 will turn a MAS 9x4 prop at 20,500rpm, with nothing tricky done to the engine. I've hit 21k once, and with some powermaster 22.5% fuel (don't ask), I was over 22k. My OS's on the Omega 15% range from 18.5rpm to 20k rpm depending on how much dirt they've eaten. If you want to get a TT, go for it. Get back to us with the numbers. But if you show up at Nats or something and you're the slowest plane out there, don't say you weren't warned.

The engines that are run are mostly the Webra, OS, and Irvine. The Mag .28 is ok in Open, but not legal in the scale classes. The OS is generally the best for someone starting out with combat because it has solid power and is easy to run.

It's important to note that some makes have powerful engines in some sizes but under powered engines in others. The TT Pro .46 is a great engine. The TT Pro .25 isn't. (or, rather, the .25 isn't high powered. I assume it's as reliable as TT engines usually are).