X2/ABC
As to the S-61F, I was told upon arrival at SA in 1966 that the 61F was an internally funded design. Of course there were US Gov't. funds involved later. Anyway, I have two inquiries going to former SA people who may ( or may not ) confirm my belief on that subject.
US Gov't. funding sometimes is obtained after a concept is designed and flown with internal company funding. An example not in my previous list is in that category: Two engineers, Sean O'Connor and Don Fowler, with SA money, designed an automatic sling load stabilization system in the late 60's/early 70's that we flew on a bailed CH-54A. Low density/high volume loads like mil-van type containers were always among the worst actors, stability-wise, and this system enabled the Crane to fly quite well at 70 kts with these containers, vice about 40 without the system. Thus it enabled IFR capability and a terrific safety improvement. The Army was ambivalent, but then gave some support and we did a simulation study with them to prove the systems value. End of story was that they still didn't incorporate the system in the Crane, but now the technology was in the public domain, and a few years later the system showed up down in Philadelphia on a CH-47 variant. As I recall it didn't make it to production there either.
On the subject of why the ABC was not supported thru the 80's, I confess to only knowing part of the story. I do know that there was a substantial number of the tech community at SA who favored this concept for the LHX, but I do not know the background as to why the SA/Boeing team decided on the concept that became Comanche. Obviously their assessment ( and the Army's ) was that speed wasn't of prime importance. So there wasn't a good idea of where an ABC product would fit in. At that time, the S-76 was absorbing all of our efforts in the small civil market, and while there were some who appreciated what an ABC could do in that market, the decision to build the S-76 essentially closed that opportunity. These are just my personal guesses.
I am curious, Dave: have you ever seen the ABC up close, in person?
Thanks,
John Dixson