The U.S.Army has a UAV in operation called the Raven. It has a wing span of 4'-3", a length of 37" and weighs 4.5 lbs. The cost is $35000 and the entire system which includes electronics goes for 1/4 mil. It can fly to 10000 ft for up to 90 minutes. It is powered by an electric motor and batteries. So much for the particulars. The capabilities of such a device are the dreams of model aircraft enthusiasts. After searching the internet, I haven't found out much in the way of details such as the type of motors and batteries used. The models now available can flyfor maybe 15 minutes at the most and a range of 1/2 mile. The Raven has an 8 mile range.
Does anyone here have better information than what I've found?