Re: A340 speed

From:         barr@netcom.com (Keith Barr)
Organization: NETCOM On-line Communication Services (408 261-4700 guest)
Date:         14 Jul 96 22:43:24 
References:   1 2 3
Followups:    1
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In article <airliners.1996.1243@ohare.chicago.com>,
C. Marin Faure <faurecm@halcyon.com> wrote:
>The problem is drag, which as you know, goes up as the speed goes up.

This is only partially correct.  Below L/D max, drag increases as you
slow down due to the increase in induced drag.

>When the cruise speed is pushed up, this extra parasite drag, plus the
>increased induced drag you're going to get anyway...

This is incorrect.  As you go faster, parasite drag increases, but since
you are lowering your required angle of attack, induced drag decreases.

Total drag (parasite + induced) is more or less U-shaped when plotted on
a chart with airspeed on the X-axis, and Drag on the Y-Axis.  The minima
is at your best Lift to Drag ratio, which is also your best glide speed.
--
Keith Barr                                       COMM AS&MEL/IA/A&IGI AERO/EIT
barr@netcom.com                                          Westminster, Colorado
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