Sky2high@aol.com wrote:

"""
 Yes, Marv, that is how my 107  Kts was arrived at on the day I  did the test.
 I defy a Lancair 320/360 pilot to hold that speed whilst  hand flying the
 airplane and doing problem analysis, checking for a landing  spot, trying a
 restart, yelling help, etc.
 
 AOA is a great device and will get you the right number, but it won't make
 much difference if yu try to "streeeeeeech" the glide.
"""

Since best glide (Vg) and best angle of climb (Vx) are functions of angle of attack, a learned particular speed for either of these flight regimes is only applicable when the aircraft weight is identical to the weight during the flight at which that speed was determined.  When weight goes up or down, so does the speed for Vx.  I agree that precisely maintaining a particular AOA while hand-flying the airplane is a demanding task, and is the reason that trimming the aircraft to that pitch attitude should be the first order of business.  Once the aircraft has been properly trimmed, small deviations from the trimmed condition due to turbulence should be self-correcting, allowing the PIC to concentrate on the other tasks at hand.

Re: your statement "but it won't make much difference if you try to "streeeeeeetch" the glide" you have to remember that once you're at L/D max and without power there isn't anything you can do to the stick to "streeeeeeetch" the glide.  The same thing applies to a takeoff from a high-density altitude airport.   After rotation if you set the AOA for Vx (L/D max), are at full power but not gaining altitude, there isn't anything you can do with the stick to make the airplane climb.  Your only option at that point is to chop the power, land, and get on the brakes.  Pulling back on the stick might buy you a couple of feet of altitude, but only momentarily, as that action will move the aircraft out of the L/D Max "sweet spot", drag goes up and now you're behind the power curve.  (L/D Max occurs at the bottom of the L/D "bucket".)  All you will have accomplished is to have changed the point at which you'll hit the trees at the end of the runway.

Assuming an engine out during cruise, pulling back to L/D max will convert some of that [cruise] airspeed into additional altitude, the most valuable commodity you can have in this situation.  Trimming to that angle should reduce the workload a bit, allowing the PIC to pick a landing spot, attempt the restart, yell for help, etc, without having to devote all of his or her efforts to flying the airplane.  (Please don't jump me... I know that the first order of business is to fly the airplane.  Trimming counts <g>.)  Of course, without an AOA indicator, you will have to have a pretty good feel for what the airplane weighs when it suddenly goes silent, and use a data set gathered from flight testing Vg at various weights to pick the proper speed to fly.  At the minimum, these tests should cover both lightly and heavily loaded situations, so a "bracket" of appropriate airspeeds will be known.

        <Marv>