Originally Posted by
NickLappos
Depends on many things, especially the TR thrust required, Soave. In a hover OGE, the losses might be: TR 4 to 5%, Transmission losses 2 1/2%, accessory loads 1%. Total 8% or so. In cruise, the TR is perhaps 2% and the rest that same.
Anyone flying a Bell with mast torque vs engine torque needles want to provide some more precise data?
I'm in no way an expert but I really surprised by your figure of only 5% for TR thrust in hover. I would have thought it much more than that for 2 reasons, one being the big difference in max total torque in the hover vs high speed flight (unloaded TR) for the later Super Puma family helis. And the second being the ease of adding or subtracting 5% torque by a relatively small TR pedal input in the hover.
Edit: oh wait a minute, did you mean 5% lost in the drive train as opposed to 5% used by the entire TR thing?