From: "Skip Slater" <skipslater@earthlink.net>
To: <lancair.list@olsusa.com>
Subject: RE: Computed AOA
Date: Thu, 10 Aug 2000 21:04:28 -0700
Message-ID: <NDBBJKBFGKPDOJHEAJMLMEOHCBAA.skipslater@earthlink.net>
Importance: Normal
In-Reply-To: <00ca01c0032c$fba1c060$0464a8c0@station4>
Reply-To: lancair.list@olsusa.com
Mime-Version: 1.0

          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
          <<  Lancair Builders' Mail List  >>
          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> 
>>
As an old carrier pilot, I have to take exception to SFS's argument and
agree with Jim Franz that a computed AOA which uses a constant weight just
isn't as accurate as the real thing.  Measuring G forces is a poor
substitute for a system which measures the amount of lift a wing is
creating.  As we know, a wing can stall at several G's or it can stall at
one.  Airspeed, weight and density altitude are all factors that also all
come into play.  Finally, you have to question the accuracy of the weight
that the user puts into the system; (garbage in, garbage out.)  The
difference between the two types of systems (computed vs. real) can
certainly be well beyond what I'd consider "inconsequential".

If you ever approach the corner of the envelope, an actual AOA taken from
the wing, a vane or other sensor is the only way you're going to have an
accurate, real-time presentation of your L/D max.  A computed AOA is little
better than a published stall speed; it's right sometimes, but a real AOA is
right ALL the time.

Skip Slater
ES in Progress


>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
LML website:   http://www.olsusa.com/Users/Mkaye/maillist.html
LML Builders' Bookstore:   http://www.buildersbooks.com/lancair

Please send your photos and drawings to marvkaye@olsusa.com.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>