Thundercracker concept design

This was a submission for the Transformers design contest which hold by tfw2005.com. The winner will get the robot design DVD by Josh Nizzi ( one of the transformers movie concept artist), but I failed to made it to final.Guess I need a stronger idea to support my concept.
Anyway, I don't know how to use 3D software, so I just paint it.
I always love planes & aircraft, so I decided to design a newer version for Thundercracker, base on the F-15 fighting jet.