Viable for giants, sure if you're into spending thousands on batteries alone! These (electric and turbine) are only going to become more widely used when the prices become comparable to gas - until then forget it. How many thousands of dollars does QQ's turbine engine cost? Rough guess - more than an entire gas powered airplane of equivalent size. How much for motor(s), ESC(s), and batteries for a full day of flying a 40% electric? Rough guess - enough to put a couple kids through college.