To Nick Lappos:
Nick, I just read somewhere on the net, that you actually flew the S-69.
I understand the ABC was studied to be able to "forget" about disymmetry of lift and retreading bladestall and so go faster.
On the S-69: Did they just ignore retreading bladestall or was there a way to actually reduce the angle of attack on the retreading blades to somewhere near zero (so there would be no stall or at least would not be of any concern - like on the cartercopter on the rotor at high forward speed, with the lift all on the wing....).
If there was a way to adjust the retreading blades:
a) How was it done (technically...)?
b) at what (forward) speed was this started?
c) at what relative angle (on the rotordisc) was it started?
I understand this would introduce fairly high bending loads on the mast, however at the speeds the s-69 was supposedly flown and the published rotorspeeds, there must have been a huge portion of the retreading blades in a stall already with a huge drag in tow!
Is there any research going on in ABC or died this with the S-69?
Thanks for your time!
3top
