Originally Posted by
Engines
Their final design solution using liquid fuelled rockets firing vertically downwards to achieve a vertical landing was, to my mind, an act of desperation.
At the time, I was a strong supporter of the Boeing design, as I liked its layout and potential simplicity - but as Scotty used to say in Star Trek. 'You canna change the laws of physics'.
Engines
From my perspective at the time, the Boeing concept was never as simple as the LM one. Even from the word go, the Boeing aircraft relied on big scary engineering stuff that was far from simple and also on subtle scary stuff that was fiendishly complex. Then the design got more and more complex as every problem required more things to be added to the design (introducing new problems). The special requirements of the C variant can't have helped and certainly did not help credibility when the PWSC started to look very different from the "simple" concept demonstrator. The "vertical lift augmentors" or whatever they were called, were just a very (very) late arrival in that line of added systems. I recall they weren't actually rockets, although the proposed supplier had ample form in that field, but with regard to exhaust characteristics they might as well have been. Their inclusion was a surpise to many people, including (and I made a point of asking at the time) many within the design team. The aircraft ended up massively complex and it was a big relief that LM, with their inherently simpler concept, won the day. Of course the LM PWSC subsequently had plenty of development issues, as has been written about at length (my favourite being the C variant's inability to trap), but I think LM were able to get through in part because they had been rewarded by their basic concept rather than persistently tripped up by it.