Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!henry From: henry@utzoo.UUCP (Henry Spencer) Newsgroups: net.space Subject: Re: Private Space Message-ID: <6143@utzoo.UUCP> Date: Sat, 16-Nov-85 21:42:01 EST Article-I.D.: utzoo.6143 Posted: Sat Nov 16 21:42:01 1985 Date-Received: Sat, 16-Nov-85 21:42:01 EST References: <8510291721.AA00286@s1-b.ARPA>, <333@ssc-vax.UUCP> <6125@utzoo.UUCP>, <125@yojna1.UUCP> Organization: U of Toronto Zoology Lines: 68 > The aerospace industry as a whole suffers because there are no simple > technologies for the construction of air- and spacecraft... > > Another reason that military and NASA craft are so expensive is that they > are built to military and government specifications... [of necessity] Every time I am about to succumb to the argument that "there just ain't no better way", I remember the A-4 Skyhawk. Dani, Brian, are you aware of it? It was a light carried-based bomber, heavily used by the US Navy in the 50s and 60s, and still in service with various other nations. What is striking about it is that the US Navy's top aeronautical-engineering people were firmly convinced, and could argue convincingly, that it was impossible. The spec said such-and-such a load, such-and-such a radius, and a maximum weight of 30,000 pounds. Most everybody thought this was reasonable, perhaps a bit tight. Ed Heinemann of Douglas said that it could be done with a much smaller aircraft, less than half that weight. Most everyone thought he was lying or crazy. I should emphasize that nobody doubted Heinemann's ability -- he had designed a good fraction of the Navy's aircraft inventory at the time -- or Douglas's ability to build aircraft promptly and well. They simply did not think that it was physically possible to meet those specs at under 15,000 pounds. Gross weight of the first production Skyhawk was 14,600 pounds. It met the spec fully. Furthermore, it was *not* optimized so single-mindedly as to make it impractical. It was 100 knots faster than the spec asked for (in fact, it set a world record for sustained speed at low altitude). It had 100 miles more combat radius. It was stressed for higher G-loading than the spec called for. Developed versions eventually carried nearly their own weight in payload. In actual combat in Vietnam, it acquired a reputation for being almost indestructible. Its serviceability exceeded that of any other combat jet in Vietnam, with better than 95% readiness. A rough guess by informed people put its maintenance load at 40% of what it would have needed if it had been built as an ordinary 30,000 pound aircraft. The result was the first combat aircraft to stay in production for a quarter of a century. The final production Skyhawks were still nearly identical to Heinemann's original design sketch. Oh yes, the Navy said "pretty please, can you possibly bring it in under a million dollars, so we can afford it?". (Money was tight at the time, and cost estimates for the 30,000 pound bomber were circa two million.) The first few hundred Skyhawks cost $860,000 each. On schedule, too. Nor was this an isolated incident, although it was the most spectacular one. The Skyhawk evolved out of a proposal for a 6,000 pound (!) supersonic interceptor. Heinemann's 68,000 pound Skywarrior met a spec that several other companies had rejected as impossible at 100,000 pounds. And -- of some relevance -- in the early 50s Heinemann's crew did a detailed study for a ONE-STAGE satellite launcher; they thought it was possible. (Some of their ideas were later used in the "one-and-a-half-stage" Atlas.) All in all, this is a remarkable example of just how much things can be tightened up when the boss knows his stuff and insists that the "standard method" just isn't good enough. It's a shame that Heinemann was too old (and working for the wrong company) to be chief engineer for the Shuttle. The aerospace business needs more Heinemanns. > By the way, Henry, what is your experience in the aerospace industry? Fortunately :-), none. I'm just a skeptical observer. -- Theorem: **NO** new technology is needed to build the Space Station. Proof: We built one fifteen years ago. Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry