Libelle 201 query

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 Tue, 22 Mar 2016 17:09:58 -0700, 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.

Thanks for the correction.

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.

That makes perfect sense. Thanks for the info.

I am guessing this is what you are asking about?

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

I wasn't asking, being happy with my Libelle as she stands, but Ommadawn
will find this interesting and I have a question or two about that rear
hinge.

- I'm guessing that it needs a spring to help the pilot swing it
up when he gets out. Is this right?

- Can the pilot close it without help and if so, how?
It looks like quite a stretch to get a grip on the frame when
you're in the glider.

- Were there any problems with the open canopy on a windy day?


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

Originally Posted by Martin Gregorie[_5_]

On Tue, 22 Mar 2016 17:09:58 -0700, 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.

Thanks for the correction.

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.

That makes perfect sense. Thanks for the info.

I am guessing this is what you are asking about?

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

I wasn't asking, being happy with my Libelle as she stands, but Ommadawn
will find this interesting and I have a question or two about that rear
hinge.

- I'm guessing that it needs a spring to help the pilot swing it
up when he gets out. Is this right?

- Can the pilot close it without help and if so, how?
It looks like quite a stretch to get a grip on the frame when
you're in the glider.

- Were there any problems with the open canopy on a windy day?


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

Steve, thank you VERY much for that image. I was hoping that someone had done it already, so I know now that it is possible. The rear hinge mod looks to be exactly what I would like to achieve. Im just surprised that more people have not done it.
The amount of angle it opens to could be adjusted to make it accessible from a seated position. I assume some sort of spring or preferably gas strut would be included within the hinge mechanism. There is ample room aft of the canopy within the hull. This region has significant structural reinforcement to support additional hardware for a hinge attachment. The canopy frame also appears to be sufficiently robust to support some form of attachment. I will discuss this with an engineering pal and see what input he has.

On Thursday, March 24, 2016 at 8:43:10 AM UTC-5, Ommadawn wrote:


Steve, thank you VERY much for that image. I was hoping that someone had
done it already, so I know now that it is possible. The rear hinge mod
looks to be exactly what I would like to achieve. Im just surprised that
more people have not done it.
The amount of angle it opens to could be adjusted to make it accessible
from a seated position. I assume some sort of spring or preferably gas
strut would be included within the hinge mechanism. There is ample room
aft of the canopy within the hull. This region has significant
structural reinforcement to support additional hardware for a hinge
attachment. The canopy frame also appears to be sufficiently robust to
support some form of attachment. I will discuss this with an engineering
pal and see what input he has.


+-------------------------------------------------------------------+
+-------------------------------------------------------------------+



--
Ommadawn

I believe he lost the space for an oxygen bottle (at least, the factory installation space) when he did that mod. Also, many easy ways to be able to lower the canopy while seated. Most notable being something like a leather cord that hangs down from the canopy into easy grasp range. You can find several other images, maybe of that same Libelle, with Google. You may also find pictures of a twin wheeled Libelle!

Link to a few shots of the one JJ modified.

https://grassrootsmotorsports.com/fo.../103076/page1/

Steve Leonard

--
Ommadawn[/i][/color]

I believe he lost the space for an oxygen bottle (at least, the factory installation space) when he did that mod. Also, many easy ways to be able to lower the canopy while seated. Most notable being something like a leather cord that hangs down from the canopy into easy grasp range. You can find several other images, maybe of that same Libelle, with Google. You may also find pictures of a twin wheeled Libelle!

Link to a few shots of the one JJ modified.

https://grassrootsmotorsports.com/fo.../103076/page1/

Steve Leonard[/quote]

Hi Steve,
I'm not too worried about losing the O2 setup, but the attachment points for it could be useful. Certainly a lanyard would be a simple solution. I don't see that the canopy needs to swing open as far as 90 degrees. I didn't have much success tracking down any more images of that particular mod though.
The JJ mod looks quite radical.

On Thursday, March 24, 2016 at 9:43:10 AM UTC-4, Ommadawn wrote:
'Martin Gregorie[_5_ Wrote:
;923127']On Tue, 22 Mar 2016 17:09:58 -0700, 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.
-
Thanks for the correction.
-
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.
-
That makes perfect sense. Thanks for the info.
-
I am guessing this is what you are asking about?

http://libelle.bugwiper.com/oyvxx_k.jpg
-
I wasn't asking, being happy with my Libelle as she stands, but Ommadawn

will find this interesting and I have a question or two about that rear
hinge.

- I'm guessing that it needs a spring to help the pilot swing it
up when he gets out. Is this right?

- Can the pilot close it without help and if so, how?
It looks like quite a stretch to get a grip on the frame when
you're in the glider.

- Were there any problems with the open canopy on a windy day?


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


Steve, thank you VERY much for that image. I was hoping that someone had
done it already, so I know now that it is possible. The rear hinge mod
looks to be exactly what I would like to achieve. Im just surprised that
more people have not done it.
The amount of angle it opens to could be adjusted to make it accessible
from a seated position. I assume some sort of spring or preferably gas
strut would be included within the hinge mechanism. There is ample room
aft of the canopy within the hull. This region has significant
structural reinforcement to support additional hardware for a hinge
attachment. The canopy frame also appears to be sufficiently robust to
support some form of attachment. I will discuss this with an engineering
pal and see what input he has.


+-------------------------------------------------------------------+
+-------------------------------------------------------------------+



--
Ommadawn

There are more photos of this on the Yahoo Libelle use group site.
UH

I believe that glider resides at my club in upstate NY. If needed, I can get more specific pictures of it.