Originally Posted by
JohnDixson
I failed to note another capability of the Comanche ducted fan: it was capable of sideward flight to 100 kts ( paced) . Pretty high bar for low speed directional control. So with all those savings reasons for the conventional tail rotor, does it have performance equal to the Comanche?
My understanding is that the current thinking is RAH-66 was over-specified and/or over-capable in terms of maneuvering capabilities, particularly in yaw and that ADS-33 requirements are getting tailored for a better balance of capability, control sensitivity, and weight/etc. Comanche always struggled with weight and the Army is attempting to shove a similar airframe with more weaponry and a little higher speed under the same ~40’ rotor. Giving up un-necessary yaw performance to reduce the weight/complexity of the yaw control system is reasonable. Of course, it’s also required for an ABC style aircraft with integrated prop to even be competitive. Yaw power isn’t a strength of a coaxial design with a lot of mass (prop, gearbox, and oh so very large horizontal stabilizer) at the end of the tail cone.
So neither aircraft will match Comanche’s impressive yaw control power and this is by design and with concurrence of USG customer, that’s pretty clear at this point.