ORIGINAL: mike109

G'day The main advantage of using a lower pitch prop on an overpowered model is to allow the model to slow down when the engine is idling to let you land more easily.

For this reason I usually use 5 pitch props on my trainers.

The AX 46 will happily spin a 12 x 6 (a friend has quite a heavy model of a PC-9) flying really well with this combination) so a 12 x 5 would be a good start. The engine will happily swing the 12 inch prop and this will keep the revs and the noise down too. Or you could try an 11 x 5 as well.

There really is only one way to find out. Try some props and see which you like.