Originally Posted by Set1SQ
Given that 3 fairly reputable, experienced, high integrity organizations are willing to invest more than $100M each in the JMR TD
The JMR TD paper proposal did not cost $100M. Sikorsky basically confirmed they were going to fly the essentially-existing S-97 as the demonstrator, despite it clearly being
far undersized for FVL-M. The S-97 was built to answer a call the government never made for AAS (a high speed scout), and its usage for FVL means that they and their partners dodge the bullet of having to spend the money ($100M) on a dedicated JMR-TD aircraft...and also dodge the bullet of having to actually build a working large scale ABC rotor.
If I was AATD, I would tell them to put their money where their mouth is and not provide the government offset money unless they build the proper tech demonstrator for the contract at hand.
Originally Posted by Set1SQ
Why would Boeing abandon the tilt rotor otherwise?
Because they are in the same boat as Sikorsky. They have a current revenue stream with the Apache, like Sikorsky, and not much incentive to supplant that with a new aircraft with potential profit-sharing with another OEM.
Originally Posted by IFMU
So rather than doing "the math" we have an off the cuff generalization that says it won't scale up.
Um, yes. This is PPRuNe, not Wolfram Alpha.
Nevertheless, what you discount from me as "off-the-cuff" is
precisely the same amount of information that Sikorsky/Boeing have historically presented to indicate that a large scale ABC rotor is feasable. Your argument seems to be "Well they are big companies with smart people, so I am sure there is a way". (Note: I remember back at AHS circa 2005 or so watching as the design chief of Kamov bureau stood up while Steve Finger was presenting on the X2, and basically chastised them for pursuing the idea of a scalable ABC.)
Well, you have chosen to ignore that same sentiment when it comes to the true occams razor....Sikorsky and Boeing are
very smart...and they know exactly what they are doing.
They are acting on the calculated risk that the Army will conclude (with their input, of course) that the JMR aircraft with its requirements is too expensive. When that happens, they will have sunk the least amount of investment by having flown the S97 as their demonstrator, while simultaneously having avoided or at least delayed having to tip their hand that the tech does not exist to build a high speed large scale ABC yet.
We will all see in time, obviously.
