Hello I am back and maybe more constant in my appearances

This is my first attempt at doing a profile and I have chosen to do an Polikarpov I-16 Type 5. This is a very very early WIP. I am using photoshop CS3 and am having a mapping issue or something I am getting bumpy and jagged images. as you can see my spinner, wheels, tail and number 4 are jagged and not smooth. I am sure as I tinker about I will figure it out, I just aquired ADOBE CS3....maybe. Anyhow, advice would be greatley appreciated.
Black 4 as flown by Mai. S. Proparenko commander of 162 IAP during 1936.