Originally Posted by
NickLappos
The original Comanche/LHX design was derived from a tradeoff contest between a conventional single rotor and an ABC, an effort that I strongly pushed for (in the hopes that an ABC would win). The 10,000 lb class helos that emerged were the same in payload, but the ABC weighed about 500 lbs more empty weight, and cost about 10% more as a result (more complex transmission, controls and rotors. Obviously, since their numbers were all nearly doubled, and they are the expensive bits.
The ABC had a 1/2 g maneuver advantage, and a 10 knot speed advantage (no compounding was added), both great combat virtues, but not valued in the LHX mission scenarios, which were low speed battle.
Just realised the main reason for coaxial to show such a small speed advantage over MR/TR in Comanche is that you need a pusher prop to make any real gains.
Any news on X2? I have never known a technically ambitious project to make the deadlines, but i'm just curious...
Mart