IGC Actions- New Glider Class/Microlift

(Chris OCallaghan) wrote in message . com...

Thanks, Gary, for the link to an interesting read. Are the referenced
works you authored currently available online?


You might find a couple of them at Jim Hendrix's oxaero.com web site
under catalogue or publications. You'll also find several other very
interesting things there.

Best Regards,
Gary Osoba

Gary and Eric, please don't get me wrong. I have the utmost respect for
both of you and the effort to understand the "superadiabatic layer". This
is just a academic debate among friends.

Just to set some credentials, 30 years ago I spent a lot of energy trying to
solve the same problem. My approach was a 50 pound, 13 meter, 35:1
inflatable flying wing made of Kevlar reinforced Mylar that could be foot
launched. The high pressure inflatable structure would have produced a
highly accurate airfoil. I still think it would work, but the materials and
construction techniques weren't available then. My legs are too old to even
think of it now.

Yes, Gary, I have seen vultures working boundary layer turbulence - it's fun
to watch. I also noted that they don't make much progress against a 20 knot
wind and that they posses an amazing landing and re-launch system if their
microlift soaring efforts don't pay off.

Low wing loading gliders working the same environment have the same problem
moving upwind as the birds but lack the land and re-launch capability. At
200', it's easy to get out of range of a suitable landing spot. The low
wing loading buys you the option of working microlift but it requires that
you operate in a hostile environment where options are limited. At 200 feet
with approximately one foot per second sink rate, you are three minutes from
a forced landing if microlift fails.

If I find myself in that situation, my most fervent wish is to get out of
it - ASAP. Once out of it, I want a big, heavy glider to take advantage of
better sources of energy found at higher altitudes.

On the other hand, I strongly suspect that similar soaring possibilities
exist at much higher altitudes and on a much larger scale. One problem in
exploiting that energy is that a TE vario can't tell the difference between
a thermal and a gust - plus it has a 2-3 second lag and a terrible
signal-to-noise ratio. Develop an instrument that has instantaneous
response plus the ability to resolve energy vectors in 3D and we may find
there are many overlooked soaring possibilities that all gliders can use.

Bill Daniels




"Gary Osoba" wrote in message
om...
Bill Daniels wrote:

If you fly at 10-12 pound wing loading in 15 knot thermals at 18000
feet,
it's superfluous.

Hello Bill:

You are correct, a glider designed to optimize Microlift conditions
would not be as well suited to cruising in these conditions. I, too,
enjoy flying very heavy wing loadings in the strongest reasonable
conditions. I am presently woking closely with Dr. Marsden on an
experimental 15m racer which will ballast to 13 psf normally, and have
designed a special system which would allow for 15 psf. This type of
flying is very exciting, and a worthwhile area to explore and push the
envelope. It is also ideally suited to pitch-based dynamic soaring
with high inertias, something that mostly captivates my attention
these days.

However, there are other fields of endeavor which are also worthwhile.
Have you ever stood on the ground in a 20 knot wind, and watched a
vulture fly from horizon to horizon at an altitude of 200' - never
once circling- against the wind? Ever wondered where is he getting
this energy? Or which of the lateral movements he is constantly making
are reactive and which ones are harvesting energy from random
turbulence? Some of us find this simple scenario at least as
interesting and exciting as the former one. At the very least, we
would like to understand it better and at the most, emulate or even
exceed it. This is one (and only one) of the things that Microlift
optimized designs are capable of doing which higher W/S approaches do
not. As it turns out, there are not simply quantitative differences
which are taking place at lower altitudes in the convecttive
environment but qualitative ones as well. The near-earth environment
does not simply contain thermal plumes which are lower than those
normally encountered in soaring flight at higher altitudes. There are
structural differences between the super-adiabatic layer, the next
mixed layer, and the higher normal soaring environment. Scale is
important here. The size of less organized structures which are not
yet thermal plumes in these lower environments is not well suited to a
12 psf W/S glider, or even a 6 spf one. Likewise, the magnitude of
stochastic but often widespread gusting and turbulence may comprise a
large fraction of the total flight energy of a low inertia glider,
whereas its nothing more than an annoyance in higher inertia systems.
With proper coordination and flight maneuvering, these smaller
turbulent events can impart repeating and substantial amounts of
energy to flight systems. However, the systems used must be matched to
the environment and it is not simply a function of wing loading. The
entrained air mass of the flying system, which is a function of not
only W/Sbut also mac and other factors must be considered.
Manueverability is very important, particularly rolling responses.

Until you have experienced this, it his hard to appreciate how it
could be as exciting as cruising at redline and 18k north of Tonopah,
while still 5k *under* cloudbase. However, I find it to be at least as
exciting. Not as high. Not as fast. But somehow just as amazing.

Not better. Not worse. Different, Bill. Something new to explore,
which is very, very old.

I guess it could be stated another way. I have never had the
opportunity to watch the launch of the Space Shuttle. I would like to.
However, if I had unlimited opportunity I suppose I would tire of it
after enough times.

I don't beilieve I will ever tire of watching vultures, or sea gulls,
or even butterflies doing their thing.

Still skeptical.

That's your prerogative. I would prescribe a little more time for
direct observation of the natural world, and a little less time trying
to view it as it rapidly recedes in your high speed rear-view mirror.

Best Regards,
Gary Osoba

Eric Greenwell wrote in message ...

Maybe, if you flew a LightHawk in the conditions it was designed for,
you'd also be less skeptical. I'd like to give it a try.

I'm kinda with Bill on this. Microlift sounds like fun, a good way to
fly on days that won't support heavier gliders - but the thought of
going crosscountry at low altitudes and low speeds, even if you can
land in anyone's backyard, just doesn't appeal to me very much. If it
did, I would be flying a hang glider or paraglider.

And microlift soaring is going to be a pretty intense activity - not
much time to relax and cruise along when you are low most of the time,
or your L/D at higher speeds is going to put you low again soon.
Nothing wrong with that (as the success of the 1-26 proves) but not
everybody's cup of tea.

The problem I see is that the cost of a high tech microlift glider is
going to be very close to a "conventional lift" glider, but the
utility will be a lot less - in that the range I can cover in
available time is a lot less. And how is that low wingloading going to
handle those fun windy. booming days? When the cloud steets are
kicking up 10 knots, and you are looking at a 30 knot headwind for
your 70 mile final glide...I think I want to have my nice heavy
wingloading, thankyou.

So if you want to see the same ground from up close, then go for it.
I think I prefer to see more ground from up high!

Another problem I see is in enticing people to go XC in microlift
gliders - sure a confident pilot will set off at 1000ft expecting to
find more microlift to keep going, out of range of any airfield, in
his $30k+ Microhawk; but your average Twirlybird is scared to death of
getting out of 10/1 from the home gliderport - he is never going to
push out at those altitudes - it's just too scary for him!

Anyway, keep up the good work - you guys are essentially filling the
gap between hang/paragliders and heavy gliders, and that is a good
thing, since in some areas (and for some pilots) that is exactly what
is needed.

Kirk

Bill Daniels wrote:

Low wing loading gliders working the same environment have the same problem
moving upwind as the birds but lack the land and re-launch capability. At
200', it's easy to get out of range of a suitable landing spot.

THis is very dependent on where you fly. How about Kansas? Or here in
Eastern Washington State, were the fields are a mile square, half of
them fallow, half of the other half in low crops, and cover hundreds of
square miles at a stretch. They are prolific producers of low lift on
many days.

The low
wing loading buys you the option of working microlift but it requires that
you operate in a hostile environment where options are limited.

Not! See above.

At 200 feet
with approximately one foot per second sink rate, you are three minutes from
a forced landing if microlift fails.

I think you grab should hold of this microlift idea because the gliders
are ideal candidates for one of your preferred launch methods: winch
launching. THese gliders require only a small, low powered winch, and to
low altitudes (500', say). An airport isn't required.
--
-----
change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

When Microlift conditions go bad, is the lift then called microsoft?
-
Mark Navarre
ASW-20 OD
California, USA
-

"Mark Navarre" wrote in message
...
When Microlift conditions go bad, is the lift then called microsoft?
-
Mark Navarre
ASW-20 OD
California, USA
-

Oh no! Gates will now patent and copyright microlift and each of us will
have to pay a licence fee per thermal. Every 2 years the thermals will get
an upgrade and will cost more, the hardware required to exploit them will
need to be more and more sophisticated but wont actually do anything new.

:-)

Ian

The thermals might be restored by opening and closing the windows.

--
Gary Boggs
3650 Airport Dr.
Hood River, Oregon, USA
97031-9613
"tango4" wrote in message
...

"Mark Navarre" wrote in message
...
When Microlift conditions go bad, is the lift then called microsoft?
-
Mark Navarre
ASW-20 OD
California, USA
-

Oh no! Gates will now patent and copyright microlift and each of us will
have to pay a licence fee per thermal. Every 2 years the thermals will get
an upgrade and will cost more, the hardware required to exploit them will
need to be more and more sophisticated but wont actually do anything new.

:-)

Ian

Kind of like buying a new car every two years because Detroit changes the
fenders or someone makes one that is called a SUV and every person in town
has to have one. If you don't like Microsoft, try doing your business
without the world of computers that they have assisted in creating. Without
MS, you would not have money to buy all the glider toys you play with every
weekend.

"tango4" wrote in message
...

"Mark Navarre" wrote in message
...
When Microlift conditions go bad, is the lift then called microsoft?
-
Mark Navarre
ASW-20 OD
California, USA
-

Oh no! Gates will now patent and copyright microlift and each of us will
have to pay a licence fee per thermal. Every 2 years the thermals will get
an upgrade and will cost more, the hardware required to exploit them will
need to be more and more sophisticated but wont actually do anything new.

:-)

Ian

On Mon, 8 Mar 2004 06:51:54 -0800, "Libelle Driver"
wrote:

Kind of like buying a new car every two years because Detroit changes the
fenders or someone makes one that is called a SUV and every person in town
has to have one. If you don't like Microsoft, try doing your business
without the world of computers that they have assisted in creating. Without
MS, you would not have money to buy all the glider toys you play with every
weekend.

Actually, that's quite easy: throughout my professional life I have
never used a DOS or Windows PC for more than a cheap terminal and word
processor.

Now, thanks to Linux and Open Office I can do everything quite nicely,
thanks, without any of Mr Gates' products.


--
martin@ : Martin Gregorie
gregorie : Harlow, UK
demon :
co : Zappa fan & glider pilot
uk :

Gary Osoba wrote:

at Lausanne, Switzerland, had voted to accept the OSTIV-proposed
definition and creation of a new class of gliders- MIcrolift.

.... of micro-interest :-(((

--
Denis

R. Parce que ça rompt le cours normal de la conversation !!!
Q. Pourquoi ne faut-il pas répondre au-dessus de la question ?