EEK turn it on and let it go huh...whats the runtime on those drones...?
Depends on a variety of factors....
First, powerplant and fuel type. There's electric, nitromethane (hobby fuel), gas (weed eater type, gas and oil mix), turbine.
Second, there's power for the avionics. This is dependant on whether or not the system will recharge itself, most don't.
Finally, payload. Weight and rotor speed dictate how long a bird will be up.
Unloaded, flight times can range from 5 minutes to 30 minutes, depending on fuel type. Electrics tend to not last that long up in the air, gassers can be up for 30 minutes or thereabouts. Of course, this is all dependent on how big the fuel tanks are (bladders, tanks, mAh, etc)
I'm a Contest Director, Lifetime AMA member, Turbine Waiver holder (and I've signed off on others). Among other things, I'm the Safety Officer for VARCHA (Virginia Radio Control Helicopter Association) and the past VP. I also Co-CD the 2nd largest helicopter event on the east coast (Heli-Invasion). Combine that with formerly working/being a part of HeliFreak.... I've been around for awhile.