Which Invention?

I have decided to model two of Leonard Da Vinci's, the tank and his fly machine, inventions and a target. I chose to model the tank because I found the design intriguing and something that could be used as to attack the target. I also decided upon the flying machine as it would be something to challenge the various techniques I have learnt over the past few weeks. The target I am going to model will be based on a person, something that could be used to train/demonstrate the power of the tank and helicopter.