Using figures obtained from wikipedia weight per available HP looks like this;
Hughes H4 5.6kg/Hp
Martin Mars 7.5
Saro Princess 6.2 (plus 8000lb jet thrust)
Boeing B29 6.1
Shorts Sunderland 6.2
PBY Catalina 6.6
Whilst that is a far from scientific survey it shows the H4 has a considerable power/weight advantage over all the others which includes a number of sucessful operational types. Whether wiKi's figure of 180,000Kg "loaded weight" refers to MAUW or weight at the time of the air test is not clear.
If the Sunderland or Catalina with aerodynamics and wing technology dating from the '30s could perform adequately on a much lower power reserves then how could the H4 fail to better them, and by a long way too?
With such a large power margin, and knowing HH's fanaticism for precision in both design and build I find it very hard to see why this machine would not have soared like an eagle.
The fact it did not is another matter entirely.
HH was under congressional investigation for misappropriation of Govt funds to build what was clearly by the end of the war an outdated anachronism. A man as smart and well connected (business wise, not mentally...) as Hughes would have see the writing on the wall not only for seaplanes but also for those 4 row piston engines engines as turbines were clearly in the ascendancy.
He could also see (maybe knew for sure) that no large orders would be likely with the war ending.
He had no interest, then, in showing what it could do which might embroil him in further pointless and time consuming development for which he could see no commercial advantage. He may have suspected that it would not perform as well as hoped and be branded a failure later. No, better to prove them wrong once and once only, then draw a line under the project with honour intact. He'd stormed out of the congressional hearing swearing to leave the USA if it did not fly - a one-time short flight is just the way a man like HH would have put one in their eye, just to show them, and then no more. He was not a man to expose himself to unnecessary risk.
It only had to fly - that is, get off the ground, to secure the last of the funds to date and to silence the critics who said it could not.
It flew. The govt paid, and the critics had to eat their words.
Either way, we'll never know, unless someone does a proper computer model to find out?
ps.
Just as a random thought, how did it get dismantled to go to that museum?
It appears to have been kept airworthy until the mid 60s at the very least, if not into the 70s. Why? There is only one reason to do that - and that is the anticipation that it might fly again. HH was a nut, for sure, but he wouldn't have poured the millions into that storage-maintenance exercise unless he had a reason. It might have been no more than the last confidence boost/ego trip "Yah-Boo-Sucks!" for a sad old loonie - but he must have believed in it's ability to carry the job. Implicitly.
For my money it was a flyer, and probably a good one. Commercial success? Who knows - doubtful probably, but a sound flyer - I'd bet my last buck on that.
As I said, how did they dismantle it for transport? Did it come apart willingly or were chainsaws involved? I've just got this wonderful vision...instead of pouring money into that silly Vulcan...Now there's a project worthy of serious money!
Last edited by Agaricus bisporus; 13th Feb 2010 at 19:06.