Diana-2 and overall performance discussion

I find it amazing that there are not more pilots flying the Diana-2 at
the worlds, since it seems to be head and shoulders above anything
else in the 15M. I guess too many pilots do not like the side stick or
lack of manufacturer reputation. Maybe the Australia fiasco stopped
many. Or are there other negative factors?

Other than that, I can not think of any other reason to pass it up for
a competition. If it were a new unproven design I could understand,
but it's not new and has already won a boatload of competitions,
despite flying in so few numbers. They always seem to clean up no
matter the competition.

Or is it that people buy what everyone else buys kind of thing?

I also think that the ever increasing wingspan in the open class has
reached a point where more does not mean necessarily better. Granted
the EB29 is leading, but look at the daily score sheets and the
performances seem so close, it's just very marginal from one to the
other. I think new materials and new structural designs to save weight
will give better results in the future, judging by the Diana-2
approach in the 15M class. Less weight = less required wing area,
higher aspect ration of wing, etc...

Feel free to discuss, as I don' see many discussions on sailplane
performance these days. It used to be a hot topic.

On Aug 5, 5:12*pm, tommytoyz wrote:
I find it amazing that there are not more pilots flying the Diana-2 at
the worlds, since it seems to be head and shoulders above anything
else in the 15M. I guess too many pilots do not like the side stick or
lack of manufacturer reputation. Maybe the Australia fiasco stopped
many. Or are there other negative factors?

Other than that, I can not think of any other reason to pass it up for
a competition. If it were a new unproven design I could understand,
but it's not new and has already won a boatload of competitions,
despite flying in so few numbers. They always seem to clean up no
matter the competition.

Or is it that people buy what everyone else buys kind of thing?

I also think that the ever increasing wingspan in the open class has
reached a point where more does not mean necessarily better. Granted
the EB29 is leading, but look at the daily score sheets and the
performances seem so close, it's just very marginal from one to the
other. I think new materials and new structural designs to save weight
will give better results in the future, judging by the Diana-2
approach in the 15M class. Less weight = less required wing area,
higher aspect ration of wing, etc...

Feel free to discuss, as I don' see many discussions on sailplane
performance these days. It used to be a hot topic.

Some people do not fit.

It is a beautiful sailplane.

On Aug 5, 4:12*pm, tommytoyz wrote:
I find it amazing that there are not more pilots flying the Diana-2 at
the worlds, since it seems to be head and shoulders above anything
else in the 15M. I guess too many pilots do not like the side stick or
lack of manufacturer reputation. Maybe the Australia fiasco stopped
many. Or are there other negative factors?

Other than that, I can not think of any other reason to pass it up for
a competition. If it were a new unproven design I could understand,
but it's not new and has already won a boatload of competitions,
despite flying in so few numbers. They always seem to clean up no
matter the competition.

Or is it that people buy what everyone else buys kind of thing?

I also think that the ever increasing wingspan in the open class has
reached a point where more does not mean necessarily better. Granted
the EB29 is leading, but look at the daily score sheets and the
performances seem so close, it's just very marginal from one to the
other. I think new materials and new structural designs to save weight
will give better results in the future, judging by the Diana-2
approach in the 15M class. Less weight = less required wing area,
higher aspect ration of wing, etc...

Feel free to discuss, as I don' see many discussions on sailplane
performance these days. It used to be a hot topic.

Diana-1 appeared to me to be a 3/4 scale 20-metre ship. That included
the cockpit. If you're 3/4 the size of a typical adult, you will fit
it perfectly! (I have sat, or should I say, squeezed sideways, into
one). If the cockpit is similarly sized in the Diane-2, the number of
potential buyers will be significantly lower than for a ship with room
for the typical American/European.

Mike

On Aug 5, 4:12*pm, tommytoyz wrote:
I find it amazing that there are not more pilots flying the Diana-2 at
the worlds, since it seems to be head and shoulders above anything
else in the 15M. I guess too many pilots do not like the side stick or
lack of manufacturer reputation. Maybe the Australia fiasco stopped
many. Or are there other negative factors?

It is seldom that a contest pilot flying a modern ship says this of
another:

"The Italians came about 1,000’ over me, pair flying beautifully in
their Dianas. I have learned not to even try to follow them. The
Dianas have a huge performance advantage and just walk away from me.
" (John Cochrane, USA team blog).

However you have to get into it before you can fly it. I tried the
Diana (-1) for size and it was hoplessly too small for me. The -2
doesn't look to me to be any bigger.

Have to wonder how much performance it would lose it it had a decent
size cockpit.

Andy

On Aug 5, 4:12*pm, tommytoyz wrote:

I find it amazing that there are not more pilots flying the Diana-2 at
the worlds, since it seems to be head and shoulders above anything
else in the 15M...

Better than average? Sure, I'll buy that. Way better than average? I'd
want to see that quantified.

I guess too many pilots do not like the side stick...

That might be. So far I've sent out several kits for converting side-
stick sailplanes to center stick, and nobody has expressed any
interest whatsoever in going the other way.

or lack of manufacturer reputation.

There might be a little bit of that, too. The majority of competition
pilots count on resale value to step themselves up to the next hot
ship. They might be leery of buying the Next Hot Ship (tm) of the
decade only to find they're out of contention because they can't
unload it for enough to buy the Next Hot Ship of the next decade.

Maybe the Australia fiasco stopped many.

It might be, but I doubt it. I think that most serious competition
pilots are level-headed enough to let one round of he-said-she-said
slide.

Or are there other negative factors?

Well, it is a rather pricy ship...

I think new materials and new structural designs to save weight
will give better results in the future, judging by the Diana-2
approach in the 15M class. Less weight = less required wing area,
higher aspect ration of wing, etc...

That is certainly true. But also, less weight = less structural margin
for crashworthiness + less margin for ground handling loads = less
robust and more easily damaged glider (yes, even with high-tech
materials and processes). All of that stuff is great for cutting-edge
pure racing machines. But one of the things that makes soaring
competition work is that used racing machines get sold off to
recreational fliers, usually at prices very near their original cost,
and the proceeds go towards the Next Hot Ship.

When the cutting-edge ships get so finely optimized that they are more
damage-prone and offer little in the way of crash protection, they
will find less interest in the used market than more conventional
gliders. Less interest means lower resale value, and less money in the
hands of the original buyer for the Next Hot Ship. So, yeah, some
independently wealthy folks with high risk tolerance and good health
coverage stand to totally sweep the competition just by throwing money
at it, and some probably already are. But I don't look towards that as
any huge force in the future of soaring competition.

Thanks, Bob K.

I think new materials and new structural designs to save weight
will give better results in the future, judging by the Diana-2
approach in the 15M class. Less weight = less required wing area,
higher aspect ration of wing, etc...

I think the Australia fiasco coupled with the 'what everyone else
flies' factor have both worked against this fine ship, although the
sidestick and need for special trailer (male root-spar stubs are perm
attached to fuse; wings have the female recip joint) haven't one it
extra points with most though either. It certainly holds it's own on
the comp circuit though, especially considering numbers, so I'm sure
there are many others out there now looking closer at it though.

If someone loaned Jim Payne their Dianna 2 for a while I bet he could
make it more popular

The Duckhawk will be an even more extreme example of the lighter
materials=less wetted formula by utilizing prepreg carbon, making it
look basically like a 2/3 scale model of an open class ship but with
an extreme envelope(300lb empty/900lb gross, 200ktVNE & 165ktVA, 50+/
1 L/D, +11/-9g's, 2sec roll rate, 30/1 aspect etc...). Sure looking
forward to seeing more progress on that project, which seems to be
backburner'd by projects like Perlan, Goshawk, TwinHawk, etc, but in
the meantime the Dianna does appear to be the highest performing 15m
ship, although not the most popular -at first.

-Paul

On Aug 5, 7:12*pm, tommytoyz wrote:
I find it amazing that there are not more pilots flying the Diana-2 at
the worlds, since it seems to be head and shoulders above anything
else in the 15M. I guess too many pilots do not like the side stick or
lack of manufacturer reputation. Maybe the Australia fiasco stopped
many. Or are there other negative factors?

Other than that, I can not think of any other reason to pass it up for
a competition. If it were a new unproven design I could understand,
but it's not new and has already won a boatload of competitions,
despite flying in so few numbers. They always seem to clean up no
matter the competition.

Or is it that people buy what everyone else buys kind of thing?

I also think that the ever increasing wingspan in the open class has
reached a point where more does not mean necessarily better. Granted
the EB29 is leading, but look at the daily score sheets and the
performances seem so close, it's just very marginal from one to the
other. I think new materials and new structural designs to save weight
will give better results in the future, judging by the Diana-2
approach in the 15M class. Less weight = less required wing area,
higher aspect ration of wing, etc...

Feel free to discuss, as I don' see many discussions on sailplane
performance these days. It used to be a hot topic.

Ask any manufacturer how many 15m gliders they've sold since 2005...
and there's your answer.

No one with any sense believed the charges made against BB from down
under. They were simply not credible. I've seen the Di-2. It's an
intriguing, beautiful, well finished machine, it goes well, I'd love
to fly one. I might even fit.

-Evan Ludeman / T8

the meantime the Dianna does appear to be the highest performing 15m
ship, although not the most popular -at first.

- Diana 2 is the highest performing 15m period. No other 15meter
glider won so much in such a short period of time. It also contributes
to the world greatest pilots flying it...You could contemplate why
commercially the project was such a disaster, but the facts speak for
themselves. It is worth reading how SH tired benefit outdated Ventus 2
platform in GP series by forcing wing loading limits benefiting
Ventuses... It sadly is dirty world we live in. To refresh the memory:

(Copy/paste from Diana website)

1st place -Sebastian Kawa 3rd FAI World Grand Prix, 2010
Santiago,Chile

3rd place - Sebastian Kawa Chilean National 2009 Santiago, Chile

2nd place-Lukasz Wojcik 15th European Gliding Championship, 2009
Nitra, Slovakia

1st place - Sebastian Kawa Pribina Cup, 2009 Nitra, Slovakia

2nd place - Lukasz Wojcik Pribina Cup, 2009 Nitra, Slovakia

1st place - Thomas Gostner 2009 15m Italian Nationals

2nd place - Stefano Ghiorzo 2009 15m Italian Nationals

1st place - Sebastian Kawa World Air Games 2009 Turin, Italy

1st place -Thomas Gostner Chilean National 2009 Santiago, Chile

2nd place- Janusz Centka 30th World Gliding Championship 2008
Lusse, Germany

1st place - Sebastian Kawa 2nd FAI World Grand Prix 2007 Omarama,
New Zealand

2nd place- Tomasz Krok 1st Polish 15m Class Championship 2007
Leszno, Poland

1stplace - Sebastian Kawa 1st Polish 15m Class Championship

1stplace - Janusz Centka 14th European Gliding Championship 2007
Issoudun, France

2ndplace- Karol Staryszak 14th European Gliding Championship 2007
Issoudun, France

1st place - Janusz Centka 29th World Gliding Championship 2006
Eskilstuna, Sweden

1st place - Janusz Centka 31st Open Class Polish Nationals 2006
Leszno, Poland

1st place - Sebastian Kawa 1st FAI World Grand Prix 2005
Saint-Aubain, France

2nd place - Janusz Centka 13th European Gliding Championship 2005
Rayskala, Finland

1st place - Janusz Centka 30th Open Class Polish Nationals.
2005 Leszno, Poland

I also sat in the Diana-1 and it fit me fine, I'm 5"10. I actually
like the side stick, though I haven't flown one. As to the structural
integrity of lighter frames - if it's lighter, it'll take less energy
to push/pull it and otherwise less force will be applied to it. Look
how robust model a/c are. They seem more crash worthy than the real
ones. So I don't readily accept that argument off hand. Lighter might
actually be stronger as it would also have less kinetic energy to move/
absorb and thus need less energy (and incur less structural stress) to
stop/move it. Of course I could be wrong on that, but I think there is
something to it.

I think there is an exponential factor here - the heavier the plane's
structure is, the stronger the wing has to be, making it heavier
still, etc...and true in reverse.

Imagine if a structure like Diana-2 were also made of prepegs? Would
it be lighter still by a significant amount? It already weighs less
than 200Kgs. I think there is a lot of improvement coming, mostly by
making the sailplanes lighter and increasing their aspect ratio for
the same wing span.

I would love to see an 18M Diana-3. Any news on something like that?

Having flown agasint the Diana2 in the more than capable hands of
Sebastian Kawa at the first two World GP Finals, I would say it is a
function of all the comments previously made - re-sale, comfort,
handling compromises, etc.

Is it a ship that has the best raw performance in 15m? Absolutely.

It really comes into its own in a 15m Grand Prix race where so long as
the pilot stays in contact with the lead pack, its lights out for
everyone else at the end. Put it in the hands of a superior pilot and
the ship is close to unbeatable. Yet, it is beatable due to the fact
that even the best pilot's decision making can never be 100% perfect
over the course of a long contest. Mistakes will be made, but they
don't hurt you as much :-)

However, many/all of the pilots flying these ships at this years
worlds are either A) on the Polish Team, or B) have a long history of
not being constrained by resale value to get their next super ship.
Take that for what it is worth.

And maybe more importantly in a topic not discussed anywhere else, the
durability of this ship is VERY suspect. Now I do not know how a very
"easy" racer would be long-term on this ship, but the ship I flew
against in the December 2007 GP Final in NZ ("BB") after, I think 2 GP
Finals, 2 Worlds, various other comps since 2005, had significant play
in all the flying surfaces.

What do I mean by "play" Well, I can recall standing with Oscar
Goudriann and Uli Schwenk and watching as the horizontal stab tips
moved fore-aft 1+ inch in our hands. Yikes.

If you can afford to buy this terrific ship, fly the snot out of it to
win, and then either find a willin buyer or junk it, then this is the
15m racer for you. Unfortunately, I've not gotten to that state of
finances yet.

Tim EY