DG Differences...

On Apr 16, 10:23*pm, "noel.wade" wrote:
Just to assuage everyone's concerns: *I am very familiar with the
importance of a trailer and good rigging. *This is why I'm especially
keen on automatic hookups and something like a Cobra trailer. *I've
SEEN the difference a trailer makes when I help certain people at my
field rig (even just in the difference between bracing / tie-down
methods in similar trailers can have a big impact), and understand
this point very well.

As for flapped performance: *The reason I talk about speed is because
if you look at things like Idaflieg test data, the polar of say a
DG-300 and an ASW-20 are nearly identical at similar wing-loadings, at
about 55 knots and below. *Above that the ASW-20 starts winning out by
a small margin to around 75 knots, and then above that the negative
flap settings seem to make a pretty noticeable difference in the polar
and the ASW-20 is the clear winner.

As another example: *Look at the Johnson review of the ASW-20. *Check
out the composite polar diagrams. *Looks like you have to get up over
75 knots before the negative flaps really start becoming superior to
the 0-degree flap position.

This is why I'm phrasing things in terms of speed or XC distance/
aggressiveness. *The "climb" flaps of the ASW-20 are certainly
superior (in small but noticeable ways) to the standard-class ships of
the late-70's. *But the 80's standard-class ships seem to be equal to
the ASW-20 in terms of minimum sink and low-speed polar curves. *Newer
airfoils seem to have a smaller "knee" in the polar curve at middling
speeds, but its still there for any standard-class ship. *However its
the upper end of the polar that really seems to be the difference
(ignoring the landing-flaps deal). *Am I off-base here?

*shrug* *My longest XC flight so far is ~130 miles total distance-over-
ground on a 4 hour flight that didn't actually get too far from home-
base (low clouds in the mountains kept me from going where I wanted).
I'd like to be able to push a little harder to get from cloud to cloud
and cover more ground - but I'm not eager to risk landouts like one or
two "aggressive" pilots in my club who get low a lot, and land out a
good 3 - 4 times every year.

My XC experience to date is in a Russia AC-4 so I'm not sure how huge
of a jump its going to be when I move up to a 40:1 ship; maybe that
increase in performance alone will be enough to make me feel better
about cloud-hopping at slightly higher than best-L/D speed, or
stretching out a bit further to find lift.

I just don't have the experience to know if I'm really going to be
jonesing for that flap handle after I fly a standard-class ship for a
year... *I thrive on challenges and new experiences - being bored with
my ship would be a nightmare!

Take care,

--Noel
P.S. *Brad - I already looked at an Apis kit. *Price of the Euro has
killed that for me! :-P

We understand your reasons. Hopefully you uderstand what we are all
saying, flaps or no flaps will not make much of a differece to your XC
results, as handicap shows. Almost everything else matter much more to
your overall experience. Either the 300 or the 20 will perform much
better than your Russia, and will look much better as well.

Ramy