Posted for "Colyn Case on earthlink" <colyncase@earthlink.net>:

""
In case I managed to confuse anyone else, it appears in my earlier comments
about the PSS/AFS AOA instrument I stated that the L/D max was Vy... my
mistake... Vy is best rate. L/D max is best ANGLE of climb, Vx. I'm much
better at keeping the words straight than I am their abbreviations. Sorry.
""
Actually, I think you had it right the first time. If power is constant
then you would have the highest climb rate when you had the highest L/D
wouldn't you?
 

[Time for a refresher.... Vx, best ANGLE of climb, provides the best altitude gain per unit of horizontal distance. and is achieved when the amount of lift available is its greatest versus the amount of drag produced by the airframe.  It occurs at the exact point when you transition from being in front of the power curve to getting behind it.  On the AOA instrument it is displayed as the transition between green and yellow (bars or LEDs, take your pick, The AOA Pro's green bar with the "X" in it is actually at a slightly lower AOA than L/D max, but using it gives you a bit more penetration and it's easier to keep a sinlge bar lit than it is to keep the lowest yellow bar fluctuating on and off, which is the true indication of being at L/D max.)   Vy, best RATE of climb, provides the best altitude gain per unit of time, and is typically at a lower AOA (and higher airspeed) than Vx.  With more airspeed comes more drag, so the angle of climb will be lower.  Just remember that Vx gets you the most altitude in the least amount of distance (great for clearing obstacles) and Vy gets you the most altitude in the least amount of time (perfect cruise climb regime).  The two are not interchangable.  Perhaps one of our more aerodynamically erudite brethren could further illustrate in a manner we could all more easily get our brains around.   <marv>          ]