Some SZD-55-1 Questions

[WDM]

I have some SZD-55 questions for folks familiar with the 55.

1) How to stop the honking sound when applying rudder in cold weather. The
noise appears to come from the mylar on the vertical and is less prevailent
in warmer weather. Though mylar appears to be in good shape and tight. This
occurs on another 55 that I am familiar with.

2) Anyone have the problem of heavy airlerons? Oringinally I thought the
problem was with the sliders in the wings. I have recently discovered
interference bewteen the fuselage and the airleron torque tube where it
exits the fuselage when the wing is mated. The torque tube is rubbing at the
lower half of the exit hole of the fuselage of the right side. Another 55 at
our field believe they have the same problem on the same side as well. The
ailerons become heavier at higher speed and greater wing loading. The
gelcoat is worn at lower radius of hole and torque tube show discoloration
from rubbing in the 7 to 4 o'clock position when viewed from side.

3) Has anyone found a place to improve fuselage venting on the 55?

Thanks in advance, WDM

[Nolaminar]

There is a fix that has worked for 55 aileron drag.
An interesting design mechansim is inside the wing root. The lower skin has to
be opened for access and this device cleaned and polished. Makes a world of
difference.
GA

[Paul B[_2_]]

On Thursday, 4 December 2003 12:00:22 UTC+10, Nolaminar wrote:
> There is a fix that has worked for 55 aileron drag.
> An interesting design mechansim is inside the wing root. The lower skin has to
> be opened for access and this device cleaned and polished. Makes a world of
> difference.
> GA

Well I know this is ten years since the the above post, but what is this fix and how would I find more specific information?

Cheers

paul

[[email protected]]

On Sunday, July 14, 2013 12:27:52 AM UTC-4, Paul B wrote:
> On Thursday, 4 December 2003 12:00:22 UTC+10, Nolaminar wrote:
>
> > There is a fix that has worked for 55 aileron drag.
>
> > An interesting design mechansim is inside the wing root. The lower skin has to
>
> > be opened for access and this device cleaned and polished. Makes a world of
>
> > difference.
>
> > GA
>
>
>
> Well I know this is ten years since the the above post, but what is this fix and how would I find more specific information?
>
>
>
> Cheers
>
>
>
> paul


Paul: SZD 55 has brass bushing at wing root that needs a few drops of machine oil thru the small pinhole every 30-50 hours to minimize aileron stiffness; if that doesn't help then I would remove ailerons, clean and lube hinges, and get some lubricant on the aileron tube where it goes thru the bearing (?teflon spray?). I would do both these before cutting into the skin.

Bill Drury

[Dan Daly[_2_]]

> 2) Anyone have the problem of heavy airlerons? Oringinally I thought the
> problem was with the sliders in the wings. I have recently discovered
> interference bewteen the fuselage and the airleron torque tube where it
> exits the fuselage when the wing is mated. The torque tube is rubbing at the
> lower half of the exit hole of the fuselage of the right side. Another 55 at
> our field believe they have the same problem on the same side as well. The
> ailerons become heavier at higher speed and greater wing loading. The
> gelcoat is worn at lower radius of hole and torque tube show discoloration
> from rubbing in the 7 to 4 o'clock position when viewed from side.

I have serial 001 - 1990 - the first production 55 and my ailerons are still very light. I do follow the lubrication plan as Bill indicates - on page 25 of the Technical Service Manual; steps 1, 2, 4, 18 are for ailerons. I can send you a copy if you don't have it (PM me here). Picture on page 55.

Aileron locks are recommended for trailering, and the stick should be immobilized.

How many hours on your 55?

Dan

[[email protected]]

On Sunday, July 14, 2013 12:28:38 PM UTC-5, Dan Daly wrote:
> > 2) Anyone have the problem of heavy airlerons? Oringinally I thought the
>
> > problem was with the sliders in the wings. I have recently discovered
>
> > interference bewteen the fuselage and the airleron torque tube where it
>
> > exits the fuselage when the wing is mated. The torque tube is rubbing at the
>
> > lower half of the exit hole of the fuselage of the right side. Another 55 at
>
> > our field believe they have the same problem on the same side as well. The
>
> > ailerons become heavier at higher speed and greater wing loading. The
>
> > gelcoat is worn at lower radius of hole and torque tube show discoloration
>
> > from rubbing in the 7 to 4 o'clock position when viewed from side.
>
>
>
> I have serial 001 - 1990 - the first production 55 and my ailerons are still very light. I do follow the lubrication plan as Bill indicates - on page 25 of the Technical Service Manual; steps 1, 2, 4, 18 are for ailerons. I can send you a copy if you don't have it (PM me here). Picture on page 55.
>
>
>
> Aileron locks are recommended for trailering, and the stick should be immobilized.
>
>
>
> How many hours on your 55?
>
>
>
>

Dan,

Since you have SN 1 you are probably a great guy to ask this question.
How serious is the "tip dragging" problem with the 55 during the initial few seconds on tow??

Thanks
Rick Lake

[Dan Daly[_2_]]

If you have a following wind, it may drop a wing briefly (I have only released once on roll since buying in 2007 so I have only had the wing touch once in 6 years), but as soon as the tail comes up it is not a problem. POH calls for dive brakes at the beginning of the roll to improve aileron effectiveness and that works quite well (stow them when the tail comes up). It is not a problem with calm or headwinds (which are, after all, what you really should have for takeoff). Similar to our club ASW-24 - which is to say, not much of a problem. I keep ailerons neutral until the tail comes up (full elevator to get this to happen as soon as I can) so as not to stall the down wing any more than it is.

I still have aileron dams on mine, though I see pictures of others without and wonder if that's part of the wing-drop legend. Theoretically they should improve aileron effectiveness, I'm told. There are 3 55's at my club, same opinion among the pilots (and 5+ at my last club).

I fly more/worry less. Love the 55 in eastern conditions, can fill it with water if out west.

DD

[[email protected]]

I have been flying an SZD-55 since 2001.
I have aileron dams/fences installed all the time. The wing drop/drag problem has happened with me only when loaded with ballast water and with the wind calm or possibly a slight tail component. Yes I know the preferred direction for take off is into wind! However when positioned in a grid of other glider for an event on a hot calm day and thermal comes along just as the tug takes up slcak in front of you the pucker factor escalates.

[[email protected]]

On Sunday, July 14, 2013 10:25:58 PM UTC-5, wrote:
> I have been flying an SZD-55 since 2001.
>
> ... The wing drop/drag problem has happened with me only when loaded with ballast water and with the wind calm or possibly a slight tail component. Yes I know the preferred direction for take off is into wind! However when positioned in a grid of other glider for an event on a hot calm day and thermal comes along just as the tug takes up slcak in front of you the pucker factor escalates.

True on many gliders. Contests will usually keep the grid in place until the tail wind is pretty substantial.

It doesn't help that most contests have helpful but not very experienced volunteers running wings. Get them level, get them balanced, the upwind wing must be a little low, and run like heck. And thanks for being here, but let's do it right.

Now to the point. It would be lovely if some of you mechanical gurus out there could develop a droppable wing wheel. I have in mind a cuff around the leading edge, a stick and a wheel below, which keeps the wings level to about 20 mph and then automatically falls off. Or maybe a waggle of the ailerons causes it to fall off. Yes, ground crew then has to run out and pick them up. But it's a small price to pay for an end to wing drops, ground loops, and the worse things that happen on winch tows.

John Cochrane

[Dan Marotta]

Do tip wheels *have* to be droppable? My LAK-17a has what amounts to roller
blade wheels in an aerodynamic fairing glued to the underside of the wing at
the tip. It also makes moving the glider around on the grid easier since
you don't need someone to hold a wing.

I can't imagine these wheels generate too much drag, but then, I don't fly
in contests...


> wrote in message
...
On Sunday, July 14, 2013 10:25:58 PM UTC-5, wrote:
> I have been flying an SZD-55 since 2001.
>
> ... The wing drop/drag problem has happened with me only when loaded with
> ballast water and with the wind calm or possibly a slight tail component.
> Yes I know the preferred direction for take off is into wind! However when
> positioned in a grid of other glider for an event on a hot calm day and
> thermal comes along just as the tug takes up slcak in front of you the
> pucker factor escalates.

True on many gliders. Contests will usually keep the grid in place until the
tail wind is pretty substantial.

It doesn't help that most contests have helpful but not very experienced
volunteers running wings. Get them level, get them balanced, the upwind wing
must be a little low, and run like heck. And thanks for being here, but
let's do it right.

Now to the point. It would be lovely if some of you mechanical gurus out
there could develop a droppable wing wheel. I have in mind a cuff around the
leading edge, a stick and a wheel below, which keeps the wings level to
about 20 mph and then automatically falls off. Or maybe a waggle of the
ailerons causes it to fall off. Yes, ground crew then has to run out and
pick them up. But it's a small price to pay for an end to wing drops, ground
loops, and the worse things that happen on winch tows.

John Cochrane

[[email protected]]

On Monday, July 15, 2013 10:07:27 AM UTC-5, Dan Marotta wrote:
> Do tip wheels *have* to be droppable? My LAK-17a has what amounts to roller
> blade wheels in an aerodynamic fairing glued to the underside of the wing at
> the tip. It also makes moving the glider around on the grid easier since
> you don't need someone to hold a wing.
>
>
Yeah, contest pilots hate to add any drag. Also a wing down with full water will take a long time to pick up, and a wing down with half water is a non-starter. So pogo sticks that keep the wings level would work better. Retracting would be nice, but we need something for the after market. 1-26 /2-33 style wheels on a cuff that fell off would work. Perhaps someone can think of a way to fold the wheel or pogo stick back into the wingtip vortex or retract it. I'm not a mechanical genius, just sick of dropping wings at contests!

John Cochrane

John Cochrane

[Martin Gregorie[_5_]]

On Mon, 15 Jul 2013 09:13:13 -0700, cochranejohnh wrote:

> Yeah, contest pilots hate to add any drag. Also a wing down with full
> water will take a long time to pick up, and a wing down with half water
> is a non-starter. So pogo sticks that keep the wings level would work
> better. Retracting would be nice, but we need something for the after
> market. 1-26 /2-33 style wheels on a cuff that fell off would work.
> Perhaps someone can think of a way to fold the wheel or pogo stick back
> into the wingtip vortex or retract it. I'm not a mechanical genius, just
> sick of dropping wings at contests!
>
A replacement tip fairing/winglet with a 'thin wheel on a stick' that
'retracts' by swinging up in line with the tip chord should work and be
reasonably low drag. However, I see two problems:

- controlling retraction if you don't want to string wires through the
wing or use a radio.
Maybe a GPS receiver to trigger retraction at 45 kts?

- the wheel would need to be fairly large (150mm?) to survive
operation off grass or rough surfaces. Not a big deal, but you're not
going to get rid of that wetted area and a thin disk would be lower
drag than something with spokes of almost any design.


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

[Dan Marotta]

At the recent Region 9 Contest in Moriarty I saw one glider with a stick
held to the under side of the wing with a suction cup. Looks like it would
fall off if the wing runner failed to remove it. I asked about it and was
told that he got it at a camera shop.


> wrote in message
...
On Monday, July 15, 2013 10:07:27 AM UTC-5, Dan Marotta wrote:
> Do tip wheels *have* to be droppable? My LAK-17a has what amounts to
> roller
> blade wheels in an aerodynamic fairing glued to the underside of the wing
> at
> the tip. It also makes moving the glider around on the grid easier since
> you don't need someone to hold a wing.
>
>
Yeah, contest pilots hate to add any drag. Also a wing down with full water
will take a long time to pick up, and a wing down with half water is a
non-starter. So pogo sticks that keep the wings level would work better.
Retracting would be nice, but we need something for the after market. 1-26
/2-33 style wheels on a cuff that fell off would work. Perhaps someone can
think of a way to fold the wheel or pogo stick back into the wingtip vortex
or retract it. I'm not a mechanical genius, just sick of dropping wings at
contests!

John Cochrane

John Cochrane

[Craig R.]

A cheap toilet plunger is fairly common in many countries for a landout takeoff aid. If it falls off after the launch, who cares.