Libelle 201 query

On Thu, 04 Feb 2016 21:51:16 +0000, Ommadawn wrote:

She is fitted for water, but the bags are removed. The last owner made
some new ones, but didn't fit them, as he wasn't happy with the result.

Another go-faster trick you might consider is fitting turbulators. This
used to add a point to the UK handicap (89 - 90) though the latest
handicap list seems to have dropped the '+turbulator' handicap. Anyway,
its a full span zigzag mylar turbulator on the under surface just ahead
of the undercambered region. Has no effect at lower speeds, but stops
flow separation in the undercambered area at high speed - at least that's
what I was told. It was on my Libelle when I bought her and certainly
high speed cruise around 70-80 kts shows less height loss than I expected.

If you're interested, talk to Glasfaser, who can supply the tape and/or
fitting instructions.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Originally Posted by Martin Gregorie[_5_]

On Thu, 04 Feb 2016 21:51:16 +0000, Ommadawn wrote:

She is fitted for water, but the bags are removed. The last owner made
some new ones, but didn't fit them, as he wasn't happy with the result.

Another go-faster trick you might consider is fitting turbulators. This
used to add a point to the UK handicap (89 - 90) though the latest
handicap list seems to have dropped the '+turbulator' handicap. Anyway,
its a full span zigzag mylar turbulator on the under surface just ahead
of the undercambered region. Has no effect at lower speeds, but stops
flow separation in the undercambered area at high speed - at least that's
what I was told. It was on my Libelle when I bought her and certainly
high speed cruise around 70-80 kts shows less height loss than I expected.

If you're interested, talk to Glasfaser, who can supply the tape and/or
fitting instructions.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Hi Martin,
That sounds almost too good to be true. Quite a simple mod for tangible gains.
I assembled the bird today and had a good look at her. Everyone was pleased with the choice. I'm a little short of achieving the skill level to fly her just yet, but will work on that. I'm still bashing around in the single Astir. Landings need attention. I have only been back flying since late August, and solo again since mid November. No need to rush.

On Sat, 06 Feb 2016 11:22:12 +0000, Ommadawn wrote:

'Martin Gregorie[_5_ Wrote:
;919283']On Thu, 04 Feb 2016 21:51:16 +0000, Ommadawn wrote:
-
She is fitted for water, but the bags are removed. The last owner made
some new ones, but didn't fit them, as he wasn't happy with the result.
-
Another go-faster trick you might consider is fitting turbulators. This

used to add a point to the UK handicap (89 - 90) though the latest
handicap list seems to have dropped the '+turbulator' handicap. Anyway,

its a full span zigzag mylar turbulator on the under surface just ahead

of the undercambered region. Has no effect at lower speeds, but stops
flow separation in the undercambered area at high speed - at least
that's what I was told. It was on my Libelle when I bought her and
certainly high speed cruise around 70-80 kts shows less height loss
than I expected.

If you're interested, talk to Glasfaser, who can supply the tape and/or

fitting instructions.


--
martin@ | Martin Gregorie gregorie. | Essex, UK org |

Hi Martin,
That sounds almost too good to be true. Quite a simple mod for tangible
gains.
I assembled the bird today and had a good look at her. Everyone was
pleased with the choice. I'm a little short of achieving the skill
level to fly her just yet, but will work on that. I'm still bashing
around in the single Astir. Landings need attention. I have only been
back flying since late August, and solo again since mid November. No
need to rush.

Yes, you'll find that landings do require attention because its
relatively weak brakes mean that a Libelle will float further and have
more of a tendency to balloon than most other gliders. For this reason
you'll see a lot of not fully held-off landings done with them: going for
a two point fully held-off landing is almost guaranteed to balloon until
you're fully up to speed with it.

Your early efforts to avoid ballooning a landing will probably result in
a main wheel landing with a tiny bounce. This is normal. FWIW there is
one other Libelle on my field. Its pilot almost always lands this
way, is an instructor, and has at least 5 years more years on type than I
have. I've worked on two-pointing mine 'just because I could' and can now
do that most times, but I've had mine for 10 years and have only managed
mostly two-pointing it for the last 4 years or so.

BTW, its useful get up to speed with slipped approaches. Libelles slip
beautifully with full brakes out and this gives a nice steep and
controllable approach when you need it.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Originally Posted by Martin Gregorie[_5_]

On Sat, 06 Feb 2016 11:22:12 +0000, Ommadawn wrote:

'Martin Gregorie[_5_ Wrote:
;919283']On Thu, 04 Feb 2016 21:51:16 +0000, Ommadawn wrote:
-
She is fitted for water, but the bags are removed. The last owner made
some new ones, but didn't fit them, as he wasn't happy with the result.
-
Another go-faster trick you might consider is fitting turbulators. This

used to add a point to the UK handicap (89 - 90) though the latest
handicap list seems to have dropped the '+turbulator' handicap. Anyway,

its a full span zigzag mylar turbulator on the under surface just ahead

of the undercambered region. Has no effect at lower speeds, but stops
flow separation in the undercambered area at high speed - at least
that's what I was told. It was on my Libelle when I bought her and
certainly high speed cruise around 70-80 kts shows less height loss
than I expected.

If you're interested, talk to Glasfaser, who can supply the tape and/or

fitting instructions.


--
martin@ | Martin Gregorie gregorie. | Essex, UK org |

Hi Martin,
That sounds almost too good to be true. Quite a simple mod for tangible
gains.
I assembled the bird today and had a good look at her. Everyone was
pleased with the choice. I'm a little short of achieving the skill
level to fly her just yet, but will work on that. I'm still bashing
around in the single Astir. Landings need attention. I have only been
back flying since late August, and solo again since mid November. No
need to rush.

Yes, you'll find that landings do require attention because its
relatively weak brakes mean that a Libelle will float further and have
more of a tendency to balloon than most other gliders. For this reason
you'll see a lot of not fully held-off landings done with them: going for
a two point fully held-off landing is almost guaranteed to balloon until
you're fully up to speed with it.

Your early efforts to avoid ballooning a landing will probably result in
a main wheel landing with a tiny bounce. This is normal. FWIW there is
one other Libelle on my field. Its pilot almost always lands this
way, is an instructor, and has at least 5 years more years on type than I
have. I've worked on two-pointing mine 'just because I could' and can now
do that most times, but I've had mine for 10 years and have only managed
mostly two-pointing it for the last 4 years or so.

BTW, its useful get up to speed with slipped approaches. Libelles slip
beautifully with full brakes out and this gives a nice steep and
controllable approach when you need it.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Hi Martin,
I enquired of the previous owner, who fitted the winglets mod about 5 years ago. He told me that although there didn't seem to be any tangible performance gains, the handling was another issue. Apparently the winglets improve very low speed handling, giving a noticeable improvement in roll response just ahead of stall. The other noticeable change was a definite resistance to side slipping. I imagine this would be a natural thing to expect when adding 'fins' to a wingtip. The long moment arm of the wings would mean that even a small vertical area that far out would resist yawing somewhat.
It will be interesting to see what he means. In any case she will remain in the hangar until I have flown the wings off the club's Astir.

On Sun, 07 Feb 2016 07:52:54 +0000, Ommadawn wrote:

I enquired of the previous owner, who fitted the winglets mod about 5
years ago. He told me that although there didn't seem to be any tangible
performance gains, the handling was another issue. Apparently the
winglets improve very low speed handling, giving a noticeable
improvement in roll response just ahead of stall.

Fair comment. As far as I can tell winglets help at the low speed end of
the performance curve while undersurface turbulators and wing root
fairings improve the high speed performance.

The fairings would be nice because the airflow round the root of early
glass was often horrible and in some cases the wing planform made it even
worse. I thought about fitting fairings, but they are quite large and
would increase the root chord and/or the fuselage width (depending on how
you fit them and where you split them for wing removal), so it seemed
likely that using them would also mean a new trailer. Thats because mine
is a box trailer that was apparently designed on the principle of "pile
all the bits in as small an area as possible, draw a line around that
with a 50mm margin and that's the size of the trailer".


A link you may find interesting and that explains the above is:
http://www.betsybyars.com/guy/soarin.../72-modif.html

I was also looking for another Will Schueman article - the one about how
he diagnosed the low speed airflow problems on his modified ASW-12 and
how he fixed them, but I can't find a link to it. I have a local copy,
but wanted to quote the URL of an online copy. Frank, if nobody comes up
with a link but you'd like to see the article, e-mail me (address is at
end of this post and I'll send you a copy.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Originally Posted by Martin Gregorie[_5_]

On Sun, 07 Feb 2016 07:52:54 +0000, Ommadawn wrote:

I enquired of the previous owner, who fitted the winglets mod about 5
years ago. He told me that although there didn't seem to be any tangible
performance gains, the handling was another issue. Apparently the
winglets improve very low speed handling, giving a noticeable
improvement in roll response just ahead of stall.

Fair comment. As far as I can tell winglets help at the low speed end of
the performance curve while undersurface turbulators and wing root
fairings improve the high speed performance.

The fairings would be nice because the airflow round the root of early
glass was often horrible and in some cases the wing planform made it even
worse. I thought about fitting fairings, but they are quite large and
would increase the root chord and/or the fuselage width (depending on how
you fit them and where you split them for wing removal), so it seemed
likely that using them would also mean a new trailer. Thats because mine
is a box trailer that was apparently designed on the principle of "pile
all the bits in as small an area as possible, draw a line around that
with a 50mm margin and that's the size of the trailer".


A link you may find interesting and that explains the above is:
http://www.betsybyars.com/guy/soarin.../72-modif.html

I was also looking for another Will Schueman article - the one about how
he diagnosed the low speed airflow problems on his modified ASW-12 and
how he fixed them, but I can't find a link to it. I have a local copy,
but wanted to quote the URL of an online copy. Frank, if nobody comes up
with a link but you'd like to see the article, e-mail me (address is at
end of this post and I'll send you a copy.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Hi Martin, all,
Well, after putting some 20 hours in the club's Astir over the last 8 weekends, I finally got the nod to take up my Libelle. I think I nagged the CFI enough that he let me go, just to get me off his back..

First flight was a 4 minute hop, as I didnt manage any lift. Second launch saw me at cloudbase, 5300' within 12 minutes. I logged 2hrs 31 on this flight and was exceeding glad and joyous! Choirs of angels sang. I was applauded by passing eagles. I can see we are going to have a long and fruitful relationship.
Thank you for all of your insightful and accurate feedback. I have read and reread each post in this thread numerous times. As a result, my maiden flight held some apprehension, but no anxiety.

Are you aware of anybody who has fitted canopy hinges to their 201?
I'm going through the mental exercise of trying to figure out a safe method of rear hinges that allow a robust attachment, whilst still engaging the locating pins.
The final setup would include a gas strut or 2.
If this mod could be adequately engineered, I think most owners would consider implementing it. A kit could be an option.
Cheers,
Frank

On Tue, 22 Mar 2016 19:06:27 +0000, Ommadawn wrote:

First flight was a 4 minute hop, as I didnt manage any lift. Second
launch saw me at cloudbase, 5300' within 12 minutes. I logged 2hrs 31 on
this flight and was exceeding glad and joyous! Choirs of angels sang. I
was applauded by passing eagles. I can see we are going to have a long
and fruitful relationship.

Great! I'm pleased you had such a good flight and are enjoying your
Libelle.

Are you aware of anybody who has fitted canopy hinges to their 201?
I'm going through the mental exercise of trying to figure out a safe
method of rear hinges that allow a robust attachment, whilst still
engaging the locating pins.

The only ones I know of for sure was the Will Schueman modified Open
Libelle, and another H.301 in the UK which has a Schuemanised nose and
cockpit. As the fuselages and wing mounts of the H.201 and H.301 are
apparently near as dammit identical (I still haven't seen an H.301
outside of a photograph), presumably what works on an H.301 would also be
OK for an H.201.

WS extended the top of the fuselage forward to a little in front of the
wing LE. Probably this was as much so he could build decent wing fairings
onto the fuselage as anything, but it also meant that he halved the
length of the canopy. He hinged the new short canopy so it opened back on
top of the extended fuselage top. I think that halving the canopy's
length is about all you can do, though the resulting canopy could be
hinged at either end or even made to open sideways, but you'd still
probably need to extend the fuselage top forward to the read of the new
canopy and mating it to the wings would be hard because they currently
extend inwards far enough to let the canopy seal onto the wing's top
surfaces. Fixing that would, I think, need the new fuselage top to extend
down inside the wing roots so it wasn't impossibly fragile and then
adding root fairings would be a good idea, if only to make the result
look like a proper, well-thought-out job. I don't know what WS did there
because I've never seen drawings or photos of his modified H.301 with the
wings off (are there any?).

Another disadvantage is that his rearward view must be poor compared with
a standard Libelle - IMO any glider in which I can't see the tailplane
tips has poor rear vision while the Libelle is excellent in this respect:
I can just see my rudder waggle when I'm strapped in.

Hinging the existing canopy sideways wouldn't work at all because cockpit
rail-mounted hinges are so far below the wing's top surface that the
canopy would be prevented from opening at all and hinging it at front or
rear would leave such a long canopy to support that any attempt at
getting in or out without external help would either leave you trapped or
with a smashed canopy.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Tuesday, March 22, 2016 at 4:30:25 PM UTC-5, Martin Gregorie wrote:


WS extended the top of the fuselage forward to a little in front of the
wing LE. Probably this was as much so he could build decent wing fairings
onto the fuselage as anything, but it also meant that he halved the
length of the canopy. He hinged the new short canopy so it opened back on
top of the extended fuselage top.

Minor correction, Martin. WS did NOT hinge his canopy. It was still a lift off and set on the ground affair. JJ Sinclair modified the fuselage on a 301 Libelle, by completely changing the canopy and making it a two piece affair, more similar to the Kestrel with the front piece fixed, and the rear piece hinged at the back. Both did it to make improved wing root fairings..

I am guessing this is what you are asking about?

http://libelle.bugwiper.com/oyvxx_k.jpg

Steve Leonard

On Tuesday, March 22, 2016 at 5:10:02 PM UTC-7, Steve Leonard wrote:
On Tuesday, March 22, 2016 at 4:30:25 PM UTC-5, Martin Gregorie wrote:


WS extended the top of the fuselage forward to a little in front of the
wing LE. Probably this was as much so he could build decent wing fairings
onto the fuselage as anything, but it also meant that he halved the
length of the canopy. He hinged the new short canopy so it opened back on
top of the extended fuselage top.

Minor correction, Martin. WS did NOT hinge his canopy. It was still a lift off and set on the ground affair. JJ Sinclair modified the fuselage on a 301 Libelle, by completely changing the canopy and making it a two piece affair, more similar to the Kestrel with the front piece fixed, and the rear piece hinged at the back. Both did it to make improved wing root fairings.

I am guessing this is what you are asking about?

http://libelle.bugwiper.com/oyvxx_k.jpg

Steve Leonard

Nice Libelle mod! Weight added is around the C/G. Uses the original latching mechanism? You can probably still open the canopy in flight.
Jim

On 3/22/2016 1:06 PM, Ommadawn wrote:

Snip...

Hi Martin, all,
Well, after putting some 20 hours in the club's Astir over the last 8
weekends, I finally got the nod to take up my Libelle. I think I nagged
the CFI enough that he let me go, just to get me off his back..

First flight was a 4 minute hop, as I didnt manage any lift. Second
launch saw me at cloudbase, 5300' within 12 minutes. I logged 2hrs 31 on
this flight and was exceeding glad and joyous! Choirs of angels sang. I
was applauded by passing eagles. I can see we are going to have a long
and fruitful relationship.
Thank you for all of your insightful and accurate feedback. I have read
and reread each post in this thread numerous times. As a result, my
maiden flight held some apprehension, but no anxiety.

Congratulations on a no-sweat transition to your new toy!!! Apprehension
without anxiety is "a good place to be" on any transition to a new-to-you
single-seat glider, in my opinion.

Bob W.

P.S. My sense is (inferring via RAS) you went about transitioning
intelligently...which usually has the desired result. (If you haven't yet,
sooner or later you'll experience the psychic pain of watching someone go
about such a transition UNintelligently, all too often with
"less-than-satisfactory" results...)