Originally Posted by
noneofyourbusiness
The Bell Invictus should be able to meet all requirements. Guessing a 12000-14000 lb gross weight with as much hp as the much larger 20000 lb Bell 525.
The Defiant X needed 10000 hp to "go fast", with a planned increase to 15000 hp. So 30000lb/10000 hp = 3lb/hp. Raider X would then need 16000lb/3 or approximately 5300 hp. It only has 3000 hp. The Sikorsky X2 had 6000lb/1800 hp = approximately 3.3 lb/hp. Raider X is trying to haul 16000 lb/3000 hp or 5.33 lb/hp.
Raider X may not be faster than the Invictus, and may even be slower. Then Raider X loses because of increased complexity and weight for no gain. Therefore Sikorsky has a strong incentive to start over with a twin engine design.
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.