Delta-3 - by flap hinge geometry. This is incorporated to handle some of the pitch control plus all of the lead/lag caused by the Coriolis effect. It looks like an offset of 15 to 16° in the teetering hinge and 10° of flap will advance the blade 0.8015" and cause a 2.68° decrease in pitch angle. For additional information to delta-3 (and the SynchroLite)

Increasing the tip weights will reduce the coning angle and therefor the longitudinal and lateral flapping. This is an advantage with the intermeshing rotors since the lateral flapping of the two rotors is to opposite sides - so what. The increases tip weights will resist cyclic changes, but there are no cyclic inputs. The large tip weights will improve the jump-takeoff. It will also offer a smaller undersling and therefor more rotor-rotor clearance. It will also reduce the desire for the rotor disk to tip back as the forward speed increases.

Author: CA BEATY

Dave, I expect you're aware that a component of main rotor torque shows up in a synchropter as a pitching moment that could make elevator control problematic.

Author: Dave Jackson

Chuck, are you are referring to the nose-up pitching moment and the need for a synchropter to have a larger than normal horizontal stabilizer? If so, then perhaps locating this oversize stabilizer further aft (actually further aft may compound the problem, because during a jump take of the increased rotor thrust will want to push the tail down)(a very far forward CofG may help because of its inertia at the time of jump and its nosedown help during forward flight??), plus the fact that the hybrid's two rotors are not providing all the thrust, may overcome this problem.

Author: CA BEATY

Yes, Dave. With skewed rotor axes and the outboard blade tips moving toward the tail, a synchropter is trying to do a "wheelie" as a result of rotor torque.

Without cyclic pitch control, it could do a backflip at zero airspeed unless a horizontal stabilizer located in the propeller slipstream could generate a sufficiently large opposing moment. You have to look at all the relevant moments to make sure this can't happen.

As a helicopter with full cyclic control, a synchropter is more stable than a single rotor machine because the CG always leads the rotor thrust line.

Author: Dave Jackson

The horizontal stabilizer may even add to this problem during a jump takeoff, when the rotors are supplying a lot of thrust.

The removal of longitudinal and lateral cyclic will be very interesting. This rigidity at the hub will, at least, always keep the CG ahead of the rotor thrust line.

I suppose that having a 'far-forward' CG will help with the jump takeoff and forward flight, but cause a problem during autorotation and flare.

Maybe locating the prop thrust line above the CG may help, since the prop and rotor receive or loose power together.