For a 3 year old my recommendation would be a flight simulator. FMS is not the best but it's free! Just log onto the website and download it. There are instructions on how to make the connection cable or you can buy one on Ebay if you don't want to do that. Real Flight G2 is the best Sim I've seen but will cost a few bucks. I'd wait about 3 years to give him a real model.