Originally Posted by
Commando Cody
Max. allowable weight for FARA has been specified by Army.
Regarding power requirements, I don't know about Sikorsky, but Bell publicly stated where their power requirement came from. For FLRAA Army had stringent Hot and High HOGE requirements. For Bell that drove the required power for Valor. With that kind of power, the speed expectation came out at 280 knots, hence the name. As it turned out V-280 was able to go 25 knots faster than that. Sikorsky may have determined Defiant-X's power requirements the same way.
Your calculations may very well be spot on. If Raider-X turns out slower, I don't think it can win except on industrial policy grounds. Aside from how far behind Army schedule it would put Sikorsky, since the Army specified one ITEP engine only for main power, Sikorsky really doesn't have an option to go to a twin. Plus, as I stated elsewhere, if Sikorsky was allowed to go to two engines, the whole FARA competition collapses and Army has to start over with a new RFP on which everyone can bid. They're already on slippery grounds with the specs as is.
https://www.defensedaily.com/engine-...ly-fy-26/army/
The Army is currently going through an Analysis of Alternatives that won't be complete for months. Will definitely be interesting to see what alternatives are being analyzed.
The X-2 power demands are more typically set by target max cruise speed and then hover and hover agility is a fall out of that, so the opposite of a tilt rotor. You're right that, in FARA's case, the competitive prototypes were heavily influenced to have a single ITE engine which will cap the max cruise speed of both aircraft. Bell's Invictus get's a little wiggle room with its SPU approach.
If the AoA process determines that a twin best suits the Army's needs, the final proposal requirements will reflect that and both competitive prototypes will feed data into the design of the new, larger FARA... assuming the aircraft fly before important decisions get made on those aircraft. Not sure how the Army will handle protests/lawsuits if the final requirements are substantially different than those of the earlier FARA phase that birthed the competitive prototypes.