From: dtice@avd23.larc.nasa.gov (David C. Tice)
Subject: Re: Sonic Boom stuff.        :-)
Organization: NASA Langley Research Center, Hampton, VA  USA
Date: Fri, 17 Apr 1992 12:15:29 GMT

In article <1992Apr16.204823.22615@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes:
>In article <1992Apr16.124224.18962@news.larc.nasa.gov> dtice@avd23.larc.nasa.gov (David C. Tice) writes:
>>>>The "compression lift" you refer to was a nice little technical white lie 
>>>I think Alfred Eggers of NASA Langley, who discovered compression lift,
>>>would be more than a little offended at this...
>>
>>My point was that the contribution of compression lift was very small on 
>>the XB-70...
>
>Before compression lift:  all WS-110 [the Weapons System requirement that
>became the XB-70] proposals specified Mach 0.8 cruise and Mach 2+ dash,
>and all were rejected by the USAF as grossly impractical (e.g. takeoff
>weights exceeding 1Mlbs, twice what the USAF was after).
>
>After compression lift:  all proposals specified Mach 3 cruise, all looked
>practical, and the one that was picked, worked.
>
>The empirical evidence very strongly suggests that you either asked the
>wrong question or misunderstood the answer.  (In particular, your original
>posting sounded like you asked about the drooped wingtips, which have
>*nothing* to do with compression lift.)
>-- 
>ISDN, n:  Incredibly Slow and Dumb      | Henry Spencer @ U of Toronto Zoology
>Networking                              |  henry@zoo.toronto.edu  utzoo!henry

A.  First of all, I had nothing to do with starting this thread.  I merely
replied to someone who thought the wing tips were for controlling compression
lift.  Check my original post you edited.  In fact, check your own post,
since you agreed with me that the tips were for L-D control and a.c. control.

B.  Nothing personal, but is there a reason I should believe someone posting
from a zoo?   I got my degree in aerospace engineering, I worked on B-1B
flight test and performance at NAA for eight years, and I have been doing
conceptual aircraft design (of large supersonic aircraft) here at NASA
Langley for the last two years.

C.  The people I asked about the XB-70 at NAA were engineers who had worked
on the airplane and had been involved in the proposal and in full-scale
development.  I asked the right question and I understood the answer,
because at the time I was laboring under the same misinformation as
some of the people in this group.

D.  The XB-70 was a dog in regards to mission performance, which may
have been because they were counting on compression lift.  The point is
that it was not a major factor!  The XB-70 never met the proposal specs.
It's a beautiful plane that never met its design goals.
 
E.  And if you care not to believe first-hand information, so be it.  Sorry
to intrude on this group with reality.

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The above comments do not reflect those of LESC or the Lockheed Corp.
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