On Wed, 9 Jan 2008 10:12:08 -0800 (PST), "noel.wade"
wrote:

But at least with Johnson (and other practical flight
tests) I have demonstrated numbers that have actually been measured
*in flight* - not theoretical or predicted numbers.

I'm pretty sure that at least for all German gliders younger than 30
years you can trust the published performances - in Germany the
idaflieg measuy every glider type with extremely elaborate yet precise
procedures - if the numbers they got were far off, word about that
would spread quickly.
Dick Johnson also does a great job, but he has a couple of performance
numbers of certain gliders that are simply far off since he is not
able to put the same amount of work into his research as idaflieg
does.


And I understand that I won't notice one or two points of L/D - that's
why I'm going for a jump from ~31:1 to at least 38:1. That big of a
spread I _will_ notice.

Yup.
But trust me - you won't feel a difference between 36:1 and 38:1...
but you are going to feel the difference between 31:1 and 1:36. vbg

I am pretty sure that any glider that was produced after the ASW-15 is
going to fit your performance demand - all of them have at least 38:1.

The reason I use sink-rate as a measure of performance is because it
directly affects climb rate in a thermal, and just trying to figure
out which airplane "thermals best" is subjective, dependant upon
conditions, and plain tough to get an accurate reading on (especially
because so few people have flown a wide range of gliders over the
years - so there's little common basis for direct comparison).

Forget that approach to judge a glider.

Pure sink rates don't work - you also need to incorporate the airspeed
in your judgement since this decides about turn radius. Not to mention
the "feeling" of the glider - LS-7 and ASW-24 have a very good sink
rate on paper, yet their airfoils need to be flown very precisely
compared to other gliders, so most pilots ended climbing significantly
worse than older gliders with a higher sink rate.

My advice: base your judgement on ergonomics (cockpit, handling on
gound and in the air, trailer) - this is going to have a far greater
influence on your performance than pure glider performance numbers.

Having only flown my Russia, Blanik L-13s, and SGS 2-33s I think I
ought to follow through with my original plan to visit Minden sometime
soon and try their Mini, LS-3a, and LS-4. I need some seat-time in
15m ships to see how they compare to my Russia...

I promise: you are going to be blown away by their performance - and
you are not going to be able to judge which of them has the better
performances. Especially flapped ships need a couple of dozen of hours
to get used to if you haven't got experience on flapped
high-performance ships yet.

Anyone have any info about SZD-55's? I had two people email me
privately to say that they thought I could pick one up for around my
$30k limit - but those folks were in England and I haven't heard
anyone from the USA talk about this model. It got plenty of favorable
reviews when it came out... ??

Few SZD-55s around, but one german top pilot used to fly one for a
long time and was very satisfied - so it seems it's comparabley in any
way to current (German) standard classgliders. You can get a
comparably young 55 for the same price as an aolder German ship.
Definitely worth a closer look.


Bye
Andreas