1) How is a high power generator, remote electric motor (heavy!), power regulation system (probably including huge buffer capacitors to deal with sudden load changes) less complex OR lighter than a driveshaft and a 90deg gearbox?
Unless you've been an R/C flyer in the last 10 years and seen the revolution there, I don't think everyone here understands just how light and efficient modern brushless motors are.
I can buy and off the shelf 20hp brushless motor that weighs 2,5kg (5lbs)!
Hacker A200-6 Motor - HAA2006
With even more exotic materials in the housing, that could probably be made even lighter.
No drive shaft, tail rotor assembly or linkage is ever going to be lighter than that.
Just as a thought experiment: an R22 probably needs, what, 10-15% of the power to power the tail rotor in its most extreme condition? That's roughly just about 20hp. So this itty bitty brushless would be able to that job. Cost less, vibrate less, weigh less and be more reliable.
And since they are so light, you can overpower the tail rotor. Let's say you stick a 30hp motor in the example above - much more than what's needed in normal conditions. This will give you an extra margin of safety and maybe avoid a LTE situation. It's there if you need it. Unless the battery is flat, that is
