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From: fiddler%concertina@Sun.COM (Steve Hix)
Newsgroups: rec.aviation,sci.space.shuttle
Subject: Re: SR71 to be retired October 1st.
Keywords: titanium, SST, Boeing, Concorde
Message-ID: <93720@sun.Corp.Sun.COM>
Date: 13 Mar 89 23:52:47 GMT
References: <1659@trantor.harris-atd.com> <5527@cognos.UUCP>
Sender: news@sun.Corp.Sun.COM
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In article <5527@cognos.UUCP>, roberts@cognos.uucp (Robert Stanley) writes:
> In article <1659@trantor.harris-atd.com> mjt@super.UUCP (Michael J. Tighe) writes:
> 
> > ...  To make matters worse, the US was planning to build
> > a mach 3 SST whereas the rest of the world was planning mach 2.5 SSTs.
> > It was "common knowledge" that mach 3 put the US at a schedule
> > disadvantage since such speeds required stainless steel or titanium
> > aircraft and there had never been a titanium aircraft built before.
> 
> This doesn't ring altogether true.  I agree that the limiting mach on
> Concorde was dictated by the choice of alloys, which were chosen on the
> grounds of practicality; there were already a great many unknowns.
> However, one of the reasons that Boeing put forward their SST proposal was
> surely because they had exactly the experience that was needed.  The XB-70
> (Valkyrie) was the pioneer in this respect, and didn't it make extensive
> use of epoxy-bonded, honey-comb titanium sandwich?

No.  It used stainless steel in its structure. (Honeycomb.)

Interesting about Boeing, especially since North American (now Rockwell)
built the XB-70.

Don't forget that North American and Lockheed both had SST designs on the
boards at the same time Boeing did.