It all kinda depends on how it was stored for that period of time. Batteries and fuel lines are a good place to start along with maybe a fuel tank if it has build up on the inside. Was the engine u plan on using out of use for that period of time also? Other then that give it a good lookover and make sure to range check the radio. I had an Astro Hog that was in my parents barn for about 15 years. It had an OS 70 surpass and Futaba conquest radio in it. All I did was blow the dust off of it installed new batteries, and got the engine purring again. Flew and ran like a dream. It wouldnt hurt to double check all the fasteners such as engine mount bolts, servo horn screws, control linkages, ect.