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From: TSHARP@BROWNVM.BITNET (H. Thomas Sharp)
Newsgroups: sci.space
Subject: Re: X-29
Message-ID: <8611101144.AA26537@s1-b.arpa>
Date: Sun, 9-Nov-86 17:39:25 EST
Article-I.D.: s1-b.8611101144.AA26537
Posted: Sun Nov  9 17:39:25 1986
Date-Received: Mon, 10-Nov-86 08:48:59 EST
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The ARPA Internet
Lines: 33

>From: weltyc%cieunix@rpics.arpa (Christopher A. Welty)
>
>   The new technology represented in the advanced forward swept
>wing aircraft (X-29) seems very interesting.  Does anyone know exactly
>what the advantages of the forward swept wing are and how the
>technology may be applied to the next generation space plane?
>
>                   -Chris


There are several advantages of a forward swept wing (FSW) over an aft
swept wing (ASW).  Among these are

   o Improved performance at high angles of attack.  For the ASW flow
     separation occurs at the wing tip and degrades the responsiveness
     of the control surfaces.  Flow separation on a FSW occurs inboard
     and generally never reaches the tip.  This allows for higher roll
     rates than would be possible with an ASW.

   o While wing sweep, either fore or aft, postpones the drag rise near
     Mach 1, a FSW has a lower wing profile drag than a ASW.  Therefore,
     one can obtain higher lift coefficients under transonic conditions.
     This translates into a greater payload capacity for a given aspect
     ratio.

Of course the major disadvantage of a FSW is it's desire to bend.  The
major contribution of the X-29 is the knowledge which has been gained on
the manufacturing and use of composites which can be tailored to the
aeroelastic bending.

 H. Thomas Sharp  (TSHARP@BROWNVM.ARPA)
 Division of Applied Mathematics
 Brown University