"BB" wrote in message
ups.com...
That's how this whole discussion got started.

What, RAS going around in circles (in sink!) ? Unheard of!

I haven't tried the high parasitic drag maneuver in a duo yet. When
demonstrated by Marty Eiler in an ASK 21, it consisted of a near VNE
dive to the ground well short of the intended landing area, and then
bleeding off the speed quite low. The key is that you lose so much
energy near VNE with spoilers out, you can afford now to bleed off
speed, even in ground effect. Most of our duo discussions have not
invovlved such high speeds -- I'm curious how it might work. I know
that being high, 80 knots and aiming at the spot in a duo is a bad
combination, but that's not what we're taling about!

As fun as the high parasitic drag maneuver is, I wonder if anyone has
ever actually used it in combat. Has anyone been so flustered and out
of synch to get monstrously high in an off field landing, then had the
presence of mind and skill left to dive to the ground at near VNE,
aiming several hundreds of yards short of the intended small paddock
with fence at the far end, and had it work? The mental attitude that
gets to the problem seems incompatible with the attitude needed to
pull this one off. If you don't aim short enough in the dive, you just
crash into the far fence at really high speed. But I'd be curious to
hear a "it worked for me" story.

John Cochrane


I have tried it with my big wing glider and for me the 'high parasite drag'
approach doesn't work unless you shift to a airspeed stabilized approach no
lower than 100 feet AGL.

My reasoning is that the ground effect starts at about a wingspan above the
ground so the bigger the wing the higher it starts. Just above the runway,
ground effect roughly doubles the L/D, (i.e. ~7:1 with full spoilers becomes
14:1) so in ground effect is a bad place to try to scrub off energy.

The key to the Duo spoilers seems to be a stabilized approach. It's a
really slippery glider and it's easy to let the airspeed creep up once your
eyes are on the aim point. In low wind/low turbulence conditions, nailing
the airspeed right on the yellow triangle while holding the glideslope to
the aim point can result in a fairly short landing. You can fly much higher
airspeed in the patern and on long final as long as the airspeed is reduced
to the calculated reference airspeed on short final.

Bill Daniels