View Full Version : Soaring Simulator Training and Competiton
RN
February 2nd 10, 10:17 PM
At the SSA Convention, Scott Manley provided an opportunity for hands
on experience with the Condor Soaring Simulator in Paul Remde's
Cumulus Soaring Booth.
Scott was also the speaker at two sessions, one on using simulators to
supplement soaring flight training, and the other flying a contest
with 4 or 5 other pilots scattered around the US and connected on the
internet.
It was obvious that Scott has put a lot of time and effort into this,
and he makes a very strong case, with real life examples, for the
benefits in training.
The contest added another dimension for experienced pilots. A highly
ranked national pilot that participated in 8 or 9 real contests last
year indicated he had been racing on the simulator once a week for
quite a while.
I have no financial interest in any of this, but came away very
excited with the potential and opportunities this offers to make
training more effective at a lower cost, and to provide some soaring
and racing during the winter. This has been available, but not widely
exposed to the soaring community as far as I can determine.
If there is sufficient interest, it seems to make sense to try to get
a monthly article started in the SSA Soaring Magazine to help folks
get started and share ideas.
Any comments, ideas and opinions will be appreciated.
bildan
February 2nd 10, 10:39 PM
On Feb 2, 3:17*pm, RN > wrote:
> At the SSA Convention, Scott Manley provided an opportunity for hands
> on experience with the Condor Soaring Simulator in Paul Remde's
> Cumulus Soaring Booth.
>
> Scott was also the speaker at two sessions, one on using simulators to
> supplement soaring flight training, and the other flying a contest
> with 4 or 5 other pilots scattered around the US and connected on the
> internet.
>
> It was obvious that Scott has put a lot of time and effort into this,
> and he makes a very strong case, with real life examples, for the
> benefits in training.
>
> The contest added another dimension for experienced pilots. A highly
> ranked national pilot that participated in 8 or 9 real contests last
> year indicated he had been racing on the simulator once a week for
> quite a while.
>
> I have no financial interest in any of this, but came away very
> excited with the potential and opportunities this offers to make
> training more effective at a lower cost, and to provide some soaring
> and racing during the winter. This has been available, but not widely
> exposed to the soaring community as far as I can determine.
>
> If there is sufficient interest, it seems to make sense to try to get
> a monthly article started in the SSA Soaring Magazine to help folks
> get started and share ideas.
>
> Any comments, ideas and opinions will be appreciated.
At a minimum, students and instructors can benefit from using Condor
as an "Animated White Board" where the instructor flies the simulated
glider through maneuvers to be taught or exploring areas where the
student has questions. Students benefit from watching high quality
computer displays from various perspectives of sometimes difficult to
explain situations. These situations can be ones too hazardous for
real flying.
Condor can be adapted to very realistic "cockpits" where the controls
are located similar to a real glider. Condor even outputs data for
force feedback controls that "feel" just like the real ones.
Condor, lacking full motion and usually force feedback, leaves the
'pilot' using only screen based visual cues to fly the simulated
'glider'. This is not a bad thing since those visual cues are
critical in becoming a truly great pilot. If you can fly solely with
limited visual cues, flying with a 360 view, tactile and kinetic cues
is easy.
Learning with a simulator frees a student from the task of scheduling
a glider, towplane, towpilot, instructor and flyable weather on the
same day. Condor even works at night. However, it's great if an
instructor can work with the student at a computer.
SoaringXCellence
February 3rd 10, 12:50 AM
On Feb 2, 2:39*pm, bildan > wrote:
> On Feb 2, 3:17*pm, RN > wrote:
>
>
>
>
>
> > At the SSA Convention, Scott Manley provided an opportunity for hands
> > on experience with the Condor Soaring Simulator in Paul Remde's
> > Cumulus Soaring Booth.
>
> > Scott was also the speaker at two sessions, one on using simulators to
> > supplement soaring flight training, and the other flying a contest
> > with 4 or 5 other pilots scattered around the US and connected on the
> > internet.
>
> > It was obvious that Scott has put a lot of time and effort into this,
> > and he makes a very strong case, with real life examples, for the
> > benefits in training.
>
> > The contest added another dimension for experienced pilots. A highly
> > ranked national pilot that participated in 8 or 9 real contests last
> > year indicated he had been racing on the simulator once a week for
> > quite a while.
>
> > I have no financial interest in any of this, but came away very
> > excited with the potential and opportunities this offers to make
> > training more effective at a lower cost, and to provide some soaring
> > and racing during the winter. This has been available, but not widely
> > exposed to the soaring community as far as I can determine.
>
> > If there is sufficient interest, it seems to make sense to try to get
> > a monthly article started in the SSA Soaring Magazine to help folks
> > get started and share ideas.
>
> > Any comments, ideas and opinions will be appreciated.
>
> At a minimum, students and instructors can benefit from using Condor
> as an "Animated White Board" where the instructor flies the simulated
> glider through maneuvers to be taught or exploring areas where the
> student has questions. *Students benefit from watching high quality
> computer displays from various perspectives of sometimes difficult to
> explain situations. *These situations can be ones too hazardous for
> real flying.
>
> Condor can be adapted to very realistic "cockpits" where the controls
> are located similar to a real glider. *Condor even outputs data for
> force feedback controls that "feel" just like the real ones.
>
> Condor, lacking full motion and usually force feedback, leaves the
> 'pilot' using only screen based visual cues to fly the simulated
> 'glider'. *This is not a bad thing since those visual cues are
> critical in becoming a truly great pilot. *If you can fly solely with
> limited visual cues, flying with a 360 view, tactile and kinetic cues
> is easy.
>
> Learning with a simulator frees a student from the task of scheduling
> a glider, towplane, towpilot, instructor and flyable weather on the
> same day. *Condor even works at night. *However, it's great if an
> instructor can work with the student at a computer.- Hide quoted text -
>
> - Show quoted text -
With regard to the visual cue comment above: I fly with many pilots
that have spent too much time on a PC-based simulator (on the order of
1 hour of PC to 3 hours of flight). One common theme in their flying
is the fixation on only looking forward while flying. It's like
pulling teeth to get them using all the horizon and looking at the
wings for level reference. I sat in the chair at the convention for
several minutes and I have many friends that love Condor. I have
"flown" SFS, SilentWings, Sailors of the Sky and Condor (oh yeah and
several versions of MSFS). They all have been improving over the
years but I hesitate to encourage anyone to spend too much time
"flying" them. I think they're excellent for learning decision making
and strategy but you need to keep it clear in your mind, It's not
flying and especially that flying requires a "swivel-head" approach
that cannot be replicated in the PC simulator.
Mike
Chris
February 3rd 10, 01:09 AM
On Feb 2, 4:50*pm, SoaringXCellence > wrote:
> On Feb 2, 2:39*pm, bildan > wrote:
>
>
>
>
>
> > On Feb 2, 3:17*pm, RN > wrote:
>
> > > At the SSA Convention, Scott Manley provided an opportunity for hands
> > > on experience with the Condor Soaring Simulator in Paul Remde's
> > > Cumulus Soaring Booth.
>
> > > Scott was also the speaker at two sessions, one on using simulators to
> > > supplement soaring flight training, and the other flying a contest
> > > with 4 or 5 other pilots scattered around the US and connected on the
> > > internet.
>
> > > It was obvious that Scott has put a lot of time and effort into this,
> > > and he makes a very strong case, with real life examples, for the
> > > benefits in training.
>
> > > The contest added another dimension for experienced pilots. A highly
> > > ranked national pilot that participated in 8 or 9 real contests last
> > > year indicated he had been racing on the simulator once a week for
> > > quite a while.
>
> > > I have no financial interest in any of this, but came away very
> > > excited with the potential and opportunities this offers to make
> > > training more effective at a lower cost, and to provide some soaring
> > > and racing during the winter. This has been available, but not widely
> > > exposed to the soaring community as far as I can determine.
>
> > > If there is sufficient interest, it seems to make sense to try to get
> > > a monthly article started in the SSA Soaring Magazine to help folks
> > > get started and share ideas.
>
> > > Any comments, ideas and opinions will be appreciated.
>
> > At a minimum, students and instructors can benefit from using Condor
> > as an "Animated White Board" where the instructor flies the simulated
> > glider through maneuvers to be taught or exploring areas where the
> > student has questions. *Students benefit from watching high quality
> > computer displays from various perspectives of sometimes difficult to
> > explain situations. *These situations can be ones too hazardous for
> > real flying.
>
> > Condor can be adapted to very realistic "cockpits" where the controls
> > are located similar to a real glider. *Condor even outputs data for
> > force feedback controls that "feel" just like the real ones.
>
> > Condor, lacking full motion and usually force feedback, leaves the
> > 'pilot' using only screen based visual cues to fly the simulated
> > 'glider'. *This is not a bad thing since those visual cues are
> > critical in becoming a truly great pilot. *If you can fly solely with
> > limited visual cues, flying with a 360 view, tactile and kinetic cues
> > is easy.
>
> > Learning with a simulator frees a student from the task of scheduling
> > a glider, towplane, towpilot, instructor and flyable weather on the
> > same day. *Condor even works at night. *However, it's great if an
> > instructor can work with the student at a computer.- Hide quoted text -
>
> > - Show quoted text -
>
> With regard to the visual cue comment above: *I fly with many pilots
> that have spent too much time on a PC-based simulator (on the order of
> 1 hour of PC to 3 hours of flight). *One common theme in their flying
> is the fixation on only looking forward while flying. *It's like
> pulling teeth to get them using all the horizon and looking at the
> wings for level reference. *I sat in the chair at the convention for
> several minutes and I have many friends that love Condor. *I have
> "flown" SFS, SilentWings, Sailors of the Sky and Condor (oh yeah and
> several versions of MSFS). *They all have been improving over the
> years but I hesitate to encourage anyone to spend too much time
> "flying" them. *I think they're excellent for learning decision making
> and strategy but you need to keep it clear in your mind, It's not
> flying and especially that flying requires a "swivel-head" approach
> that cannot be replicated in the PC simulator.
>
> Mike
As a real life glider pilot, who flies both Condor and Silent Wings
actively, I agree with your point about the need to develop a habit of
keeping your head out of the cockpit. But it's simply not true that
you cannot develop a good, head out of the cockpit habit using these
simulators. I always fly with a simple, and relatively inexpensive,
head tracking system that sits on top of the monitor. The system
exaggerates your head movements so that you can look far too the left
or right, up or down, while still facing the monitor. This allows you
look around constantly--useful for judging your landing, reading the
clouds, and also flying in gaggles during online competitions. While
it's not perfect, I simply hate to fly simulators without it now. I
would certainly advocate it being used in any student training setup.
Chris
JS
February 3rd 10, 01:50 AM
Excellent use of technology.
There was an article a year or so ago in S+G about soloing a student
in an AS-K21 with something unbelievable, perhaps four flights. This
was a after he had trained in a simulator, built around the front
fuselage of a two seat glider procured from a wreck. I believe Condor
was the software.
The student can be allowed to see what happens in bad situations
such as getting on the back side of the ridge or low on final.
The "animated white board" as Bill put it.
Jim
Chris
February 3rd 10, 04:36 PM
On Feb 2, 5:09*pm, Chris > wrote:
> On Feb 2, 4:50*pm, SoaringXCellence > wrote:
>
>
>
>
>
> > On Feb 2, 2:39*pm, bildan > wrote:
>
> > > On Feb 2, 3:17*pm, RN > wrote:
>
> > > > At the SSA Convention, Scott Manley provided an opportunity for hands
> > > > on experience with the Condor Soaring Simulator in Paul Remde's
> > > > Cumulus Soaring Booth.
>
> > > > Scott was also the speaker at two sessions, one on using simulators to
> > > > supplement soaring flight training, and the other flying a contest
> > > > with 4 or 5 other pilots scattered around the US and connected on the
> > > > internet.
>
> > > > It was obvious that Scott has put a lot of time and effort into this,
> > > > and he makes a very strong case, with real life examples, for the
> > > > benefits in training.
>
> > > > The contest added another dimension for experienced pilots. A highly
> > > > ranked national pilot that participated in 8 or 9 real contests last
> > > > year indicated he had been racing on the simulator once a week for
> > > > quite a while.
>
> > > > I have no financial interest in any of this, but came away very
> > > > excited with the potential and opportunities this offers to make
> > > > training more effective at a lower cost, and to provide some soaring
> > > > and racing during the winter. This has been available, but not widely
> > > > exposed to the soaring community as far as I can determine.
>
> > > > If there is sufficient interest, it seems to make sense to try to get
> > > > a monthly article started in the SSA Soaring Magazine to help folks
> > > > get started and share ideas.
>
> > > > Any comments, ideas and opinions will be appreciated.
>
> > > At a minimum, students and instructors can benefit from using Condor
> > > as an "Animated White Board" where the instructor flies the simulated
> > > glider through maneuvers to be taught or exploring areas where the
> > > student has questions. *Students benefit from watching high quality
> > > computer displays from various perspectives of sometimes difficult to
> > > explain situations. *These situations can be ones too hazardous for
> > > real flying.
>
> > > Condor can be adapted to very realistic "cockpits" where the controls
> > > are located similar to a real glider. *Condor even outputs data for
> > > force feedback controls that "feel" just like the real ones.
>
> > > Condor, lacking full motion and usually force feedback, leaves the
> > > 'pilot' using only screen based visual cues to fly the simulated
> > > 'glider'. *This is not a bad thing since those visual cues are
> > > critical in becoming a truly great pilot. *If you can fly solely with
> > > limited visual cues, flying with a 360 view, tactile and kinetic cues
> > > is easy.
>
> > > Learning with a simulator frees a student from the task of scheduling
> > > a glider, towplane, towpilot, instructor and flyable weather on the
> > > same day. *Condor even works at night. *However, it's great if an
> > > instructor can work with the student at a computer.- Hide quoted text -
>
> > > - Show quoted text -
>
> > With regard to the visual cue comment above: *I fly with many pilots
> > that have spent too much time on a PC-based simulator (on the order of
> > 1 hour of PC to 3 hours of flight). *One common theme in their flying
> > is the fixation on only looking forward while flying. *It's like
> > pulling teeth to get them using all the horizon and looking at the
> > wings for level reference. *I sat in the chair at the convention for
> > several minutes and I have many friends that love Condor. *I have
> > "flown" SFS, SilentWings, Sailors of the Sky and Condor (oh yeah and
> > several versions of MSFS). *They all have been improving over the
> > years but I hesitate to encourage anyone to spend too much time
> > "flying" them. *I think they're excellent for learning decision making
> > and strategy but you need to keep it clear in your mind, It's not
> > flying and especially that flying requires a "swivel-head" approach
> > that cannot be replicated in the PC simulator.
>
> > Mike
>
> As a real life glider pilot, who flies both Condor and Silent Wings
> actively, I agree with your point about the need to develop a habit of
> keeping your head out of the cockpit. But it's simply not true that
> you cannot develop a good, head out of the cockpit habit using these
> simulators. I always fly with a simple, and relatively inexpensive,
> head tracking system that sits on top of the monitor. The system
> exaggerates your head movements so that you can look far too the left
> or right, up or down, while still facing the monitor. This allows you
> look around constantly--useful for judging your landing, reading the
> clouds, and also flying in gaggles during online competitions. While
> it's not perfect, I simply hate to fly simulators without it now. I
> would certainly advocate it being used in any student training setup.
>
> Chris
A few people have now emailed me and asked me about the head tracking
unit I'm using. To avoid a lot of individual responses, here's the
link:
http://www.naturalpoint.com/trackir/products/trackir5/
I'm using the slightly older TrackIR 4, but running the same software
at TrackIR 5. Condor only supports it partially--you can look left,
right, up, and down. In SilentWings you also get the ability to tilt
your head and can lean forward or back and have the screen reflect
these motions. In both cases, I think it adds a lot to the "flying"
experience.
Chris
mattm[_2_]
February 3rd 10, 04:39 PM
On Feb 2, 8:50*pm, JS > wrote:
> Excellent use of technology.
> * There was an article a year or so ago in S+G about soloing a student
> in an AS-K21 with something unbelievable, perhaps four flights. This
> was a after he had trained in a simulator, built around the front
> fuselage of a two seat glider procured from a wreck. I believe Condor
> was the software.
> * The student can be allowed to see what happens in bad situations
> such as getting on the back side of the ridge or low on final.
> The "animated white board" as Bill put it.
> Jim
I'll have to dig out the article. The approach was to do all the
primary
instruction in the simulator. This was a full-up cockpit surrounded
by
large projection screens, so it resembled the large trainers used by
the military and airlines (without the moving platform though). The
student
was taken all the way through solo on the simulator. Then, teaching
the student to fly a real glider was more like transition training.
However,
there is a minimum of 20 flights required to solo in the UK, so that
was
mostly burned off doing pattern flights in a motorglider. Only about
4
flights were required in an actual G103 to solo the student -- a high
flight
to review tow and airwork, a couple of pattern flights to nail the
landing,
and a rope break I think. As a comparison I've soloed someone in as
few
as 6 flights (they were an experienced airline pilot (and fairly
young))
and almost soloed someone in 4 flights (who had a career instructing
on carrier decks), and know someone who soloed in 3 flights (an
astronaut).
The simulator that the BGA built cost something around $10K, which
is approaching what a basic trainer can cost (L13, K7, 2-33).
However,
you skip all that annual cost for insurance, tie downs, maintenance,
etc.
I think it would be great for our club, except that we don't really
have a place
to keep it (we live at a public airport and only have a storage shed
to ourselves).
I have seen several students come from a self-taught simulator
background
over the years. They often make excellent pilots in the end, but we
have to
spend a fair amount of time building in the scan habit and getting
them to
coordinate their turns, compared with other students. The casual
simulator
user at home often doesn't spring for rudder pedals, since they're
quite
expensive. They use "auto-coordinate" or else use a twist grip, which
doesn't help when they get in the real plane. RC pilots often have
the
same trouble with coordination, but can wind up as superior pilots in
the end.
However, even with those limits Condor can seriously improve cross
country (especially contest) flying. I spent half a winter flying it
before
my second RL contest and improved from almost last place to 5th (in
a field of 25). It's a great way to practice what you have to do to
fly
fast -- thermal well, read the conditions to come, plan for them,
select the best lift, extend your glides, and fly a successful final
glide.
You also get to fly with some great pilots from around the world in
the
online contests -- the Hungarian national team spends the whole winter
flying them to keep their skills sharp.
I've also used the online contests to help our budding cross country
pilots
learn some of those skills. Normally they just get our bronze badge
class
plus some fox&hound coaching to learn, since we don't have a cross
country
capable two-place glider. Condor isn't quite a two-place setup
(unless you
build one of those simulators out of a wreck) but you can readily do
fox&hound from the comfort of your own home.
-- Matt
Frank[_12_]
February 4th 10, 11:23 PM
On Feb 2, 5:17*pm, RN > wrote:
> At the SSA Convention, Scott Manley provided an opportunity for hands
> on experience with the Condor Soaring Simulator in Paul Remde's
> Cumulus Soaring Booth.
>
> Scott was also the speaker at two sessions, one on using simulators to
> supplement soaring flight training, and the other flying a contest
> with 4 or 5 other pilots scattered around the US and connected on the
> internet.
>
> It was obvious that Scott has put a lot of time and effort into this,
> and he makes a very strong case, with real life examples, for the
> benefits in training.
>
> The contest added another dimension for experienced pilots. A highly
> ranked national pilot that participated in 8 or 9 real contests last
> year indicated he had been racing on the simulator once a week for
> quite a while.
>
> I have no financial interest in any of this, but came away very
> excited with the potential and opportunities this offers to make
> training more effective at a lower cost, and to provide some soaring
> and racing during the winter. This has been available, but not widely
> exposed to the soaring community as far as I can determine.
>
> If there is sufficient interest, it seems to make sense to try to get
> a monthly article started in the SSA Soaring Magazine to help folks
> get started and share ideas.
>
> Any comments, ideas and opinions will be appreciated.
The editor of the SSA mag has been in possession of a quite detailed
"How to Get Started With Condor" article for 6 months or more.
Apparently it has been relegated to the dustbin :(
TA
RN
February 5th 10, 12:24 AM
TA's post indicates the issue that we need to address.
There are a lot of folks doing a lot of interesting and leading edge
development in using low cost simulators for flight training,
developing new skills, and having some fun when the snow flies up
north. Many soaring pilots and potential soaring pilots can benefit.
This thread indicates a lot of interesting things are happening.
We need to get the SSA mag on board to provide support and to provide
information to a much broader audience than just the RAS regulars.
RN
bildan
February 5th 10, 01:42 AM
On Feb 4, 5:24*pm, RN > wrote:
> TA's post indicates the issue that we need to address.
>
> There are a lot of folks doing a lot of interesting and leading edge
> development in using low cost simulators for flight training,
> developing new skills, and having some fun when the snow flies up
> north. Many soaring pilots and potential soaring pilots can benefit.
>
> This thread indicates a lot of interesting things are happening.
>
> We need to get the SSA mag on board to provide support and to provide
> information to a much broader audience than just the RAS regulars.
>
> RN
A good article in Soaring would be nice but we need to do a lot more
than that. We need to be writing about some real simulator systems
used by actual training organizations.
If you take a look at the Condor web page http://www.condorsoaring.com/index.htm
and click "Forums" then "Cockpit builders" you can read about some
interesting projects.
What I think is needed is a simple to make "cockpit" something like
http://forum.condorsoaring.com/viewtopic.php?f=14&t=9492 The "Cockpit"
should have a second monitor for the instruments so the projected
outside view doesn't need to display them. A real glider nose section
isn't necessary. If you aren't handy at welding, a similar "simchair"
could be made with PVC pipe.
Then we need a projection system that provides a wider outside view.
It's also possible to provide quite realistic "force feedback" so the
controls "feel" like the real ones.
I feel strongly that, while a PC simulator will never be a replacement
for real time in a glider, this could be very useful adjunct to a
training program.
bildan
February 5th 10, 01:44 AM
On Feb 4, 6:42*pm, bildan > wrote:
> On Feb 4, 5:24*pm, RN > wrote:
>
> > TA's post indicates the issue that we need to address.
>
> > There are a lot of folks doing a lot of interesting and leading edge
> > development in using low cost simulators for flight training,
> > developing new skills, and having some fun when the snow flies up
> > north. Many soaring pilots and potential soaring pilots can benefit.
>
> > This thread indicates a lot of interesting things are happening.
>
> > We need to get the SSA mag on board to provide support and to provide
> > information to a much broader audience than just the RAS regulars.
>
> > RN
>
> A good article in Soaring would be nice but we need to do a lot more
> than that. *We need to be writing about some real simulator systems
> used by actual training organizations.
>
> If you take a look at the Condor web pagehttp://www.condorsoaring.com/index.htm
> and click "Forums" then "Cockpit builders" you can read about some
> interesting projects.
>
> What I think is needed is a simple to make "cockpit" something likehttp://forum.condorsoaring.com/viewtopic.php?f=14&t=9492The "Cockpit"
> should have a second monitor for the instruments so the projected
> outside view doesn't need to display them. *A real glider nose section
> isn't necessary. *If you aren't handy at welding, a similar "simchair"
> could be made with PVC pipe.
>
> Then we need a projection system that provides a wider outside view.
> It's also possible to provide quite realistic "force feedback" so the
> controls "feel" like the real ones.
>
> I feel strongly that, while a PC simulator will never be a replacement
> for real time in a glider, this could be very useful adjunct to a
> training program.
As I clicked on "send" I thought of something else. We REALLY need
some more hi-res US scenery like what is available for the Alps.
There has to be some readers of this newsgroup who know how to do
this.
If we had good scenery around popular gliderports, students could be
practicing in their local area.
Eric Greenwell
February 5th 10, 04:49 AM
Frank wrote:
> On Feb 2, 5:17 pm, RN > wrote:
>
>> I have no financial interest in any of this, but came away very
>> excited with the potential and opportunities this offers to make
>> training more effective at a lower cost, and to provide some soaring
>> and racing during the winter. This has been available, but not widely
>> exposed to the soaring community as far as I can determine.
>>
>> If there is sufficient interest, it seems to make sense to try to get
>> a monthly article started in the SSA Soaring Magazine to help folks
>> get started and share ideas.
>>
>> Any comments, ideas and opinions will be appreciated.
>>
>
> The editor of the SSA mag has been in possession of a quite detailed
> "How to Get Started With Condor" article for 6 months or more.
> Apparently it has been relegated to the dustbin :(
>
It took that long to get my recent article on the Perlan Project
accepted and scheduled for publication. I don't know why it was so
difficult, but sending a copy to my SSA Director with some details on
how hard it was to get the article "adjusted" to Soaring Magazine's
requirements, things went more smoothly and quickly. Coincidence? Don't
know, but it was harder to get published than any of the other eight
articles I've submitted over the years. Keep trying. It's a good idea
that needs exposure.
--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org
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