Wing tie down question

[MNLou]

I will by flying my LAK17at at contests and camps this summer. I will need to tie out the glider.

I am trying to figure out a good way to tie down the wings. With 18m wingtips, the ailerons extend almost to the end of the wingtip. I am concerned about damaging the aileron if I just throw a strap over the top and tighten down.

Any ideas would be greatly appreciated.

(I did post a question on the LAK17a Yahoo group as well.)

Lou

[[email protected]]

How about a wing-bow made of fibreglass with some sort of eyelets that you can tie rope to? If the shape of the wing makes it difficult to slip over the tip you could make it hinging and latched at the rear.

Also stops your ailerons (and flaps if flaperons) from flapping around in the wind.

Nick.

[Ben Coleman]

On Thursday, 12 May 2016 08:51:09 UTC+9:30, wrote:
> How about a wing-bow made of fibreglass with some sort of eyelets that you can tie rope to? If the shape of the wing makes it difficult to slip over the tip you could make it hinging and latched at the rear.
>
> Also stops your ailerons (and flaps if flaperons) from flapping around in the wind.
>
> Nick.

That's what I've seen for Ventus 16.6...tie down one side with wing dolly and other side fibreglass wing cuff.

Cheers Ben

[[email protected]]

If you use the one from your trailer you need to remind your crew that they have to collect it from your tiedown in the event of an outlanding. Either that or put it in your trailer every day before takeoff.

I think it's probably best to have one dedicated to the job.

Nick

[JS]

On Wednesday, May 11, 2016 at 3:55:21 PM UTC-7, MNLou wrote:
> I will by flying my LAK17at at contests and camps this summer. I will need to tie out the glider.
>
> I am trying to figure out a good way to tie down the wings. With 18m wingtips, the ailerons extend almost to the end of the wingtip. I am concerned about damaging the aileron if I just throw a strap over the top and tighten down.
>
> Any ideas would be greatly appreciated.
>
> (I did post a question on the LAK17a Yahoo group as well.)
>
> Lou

Most glider manufacturers neglect this minor detail as any sort of option.

Gliders with a single wing panel per side are usually easy. One approach there is a webbing "bra" over the tip. Not just one loop, there should be a strap to stop the bra from creeping inboard to the ailerons. Had those for LS4 and LS6.

Can you put a tube through the wing at the outboard end of the inner panel, bonded to the tip rib and spar if possible?
Run a forged eyebolt with padded washers through it for tiedown.
Tape over the holes in flight. That mod on Nimbus 3 worked extremely well, worked with typical GA tiedown area points and was at the break point in the covers.

A similar approach: Bond a piece of T3, threaded for an eyebolt, into the outer end of the spoiler boxes. Only one hole per wing to tape. Not at a break point, so you need to have holes cut in the covers to accommodate this.

All of those can be packed in your landout kit.
Jim

[Mark628CA]

If you are intending to tie down overnight and do not want to damage your wings and control surfaces, use a webbing tie down strap OVER a wing stand. (On BOTH wings!) The wing stand cradle is positioned to prevent aileron movement and the webbing strap goes over the leading edge, the top of the wing and control surface and down to the tiedown point on the ground. With the wing stand cradle at the same point, the wings will remain rock solid with no unwanted flex or movement. Don't forget to use some sort of gust lock on the rudder (and elevator if you think it is necessary.

Personally, I prefer a hangar, but they don't fit in the baggage compartment.

[Martin Gregorie[_5_]]

On Wed, 11 May 2016 15:55:18 -0700, MNLou wrote:

> I will by flying my LAK17at at contests and camps this summer. I will
> need to tie out the glider.
>
> I am trying to figure out a good way to tie down the wings. With 18m
> wingtips, the ailerons extend almost to the end of the wingtip. I am
> concerned about damaging the aileron if I just throw a strap over the
> top and tighten down.
>
Don't know whether this helps, but....

I made a pair tip caps. These are glass+carbon mouldings. The top and
bottom surfaces are joined at the TE and round the end of the tip. They
are handed and slip onto the wingtips from behind. There's an alloy
bobbin mounted on a piece of 1.5mm epoxy plate and glued onto the upper
surface of the mouldings. Each tip-cap is lined with pieces cut from 6mm
foam-rubber camping mat that is glued in so it won't fall out and get
lost.

To use them, I put trestles under both wings to steady them, slip a tip
cap over each and run soft climbing rope round the bobbin, forward over
the LE and down to a Claw tiedown placed directly under the LE and with
the top rope angled 45 degrees inward where it is on top of the wing. The
rope is snugged down to hold the wings firmly on the trestles. Angling
the rope in makes sure the tip-caps cant work off outwards and puting the
centre of the Claw directly below the LE minimises fore/aft loading on
the wings.

These work well on my Libelle and fit nicely with wing covers on or off.
I've seen no sign of the ropes getting pulled loose, even in quite a lot
of wind.

If you want the tip caps to stop ailerons/flaperons from flapping, make
them long enough spanwise to fit over the control surface' outer ends and
deep enough chordwise to extend 1.5 to 2 times the width of the control
surface. By putting the bobbins well outboard you should be able to feed
the rope tension onto the fixed TE outboard on the control surface and
avoid loading its hinges.

> Any ideas would be greatly appreciated.
>
If you like this idea and would like to see pictures, just ask: there are
none online at present but putting them up is no problem. I made pics of
the bits while I was assembling them.


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

[glidergreg]

On Wednesday, May 11, 2016 at 5:55:21 PM UTC-5, MNLou wrote:
> I will by flying my LAK17at at contests and camps this summer. I will need to tie out the glider.
>
> I am trying to figure out a good way to tie down the wings. With 18m wingtips, the ailerons extend almost to the end of the wingtip. I am concerned about damaging the aileron if I just throw a strap over the top and tighten down.
>
> Any ideas would be greatly appreciated.
>
> (I did post a question on the LAK17a Yahoo group as well.)
>
> Lou

Just thinking, if you remove the wingtips and replace it with a rod or tube which fits into the wingtip receiver hole, you could then use the extending rod or tube as a tie-down point.

[Dan Marotta]

I sometimes tie down my LAK-17a by the holes in the wing tip wheels
using ropes with metal hooks that fit through the holes in the tip wheel
supports. I also support the wings with the wing stands. I don't know
how the wing tip wheels are attached to the wings, however, and if only
glued on, this is probably not a good method. This is for short-term
use only.

I also sometimes use nylon straps consisting of a loop which encircles
the wingtip in a chord-wise direction, has a half loop sewn to it in a
span-wise direction, which continues a couple of inches inboard with a
steel ring sewn to the extension. Ropes are tied to the rings and
angled inward to prevent the loops slipping off the tops. Of course the
wings are supported by wing stands.


On 5/11/2016 7:02 PM, Mark628CA wrote:
> If you are intending to tie down overnight and do not want to damage your wings and control surfaces, use a webbing tie down strap OVER a wing stand. (On BOTH wings!) The wing stand cradle is positioned to prevent aileron movement and the webbing strap goes over the leading edge, the top of the wing and control surface and down to the tiedown point on the ground. With the wing stand cradle at the same point, the wings will remain rock solid with no unwanted flex or movement. Don't forget to use some sort of gust lock on the rudder (and elevator if you think it is necessary.
>
> Personally, I prefer a hangar, but they don't fit in the baggage compartment.

--
Dan, 5J

[Oscar-Hotel-Mike]

I bought a pair of JJ Sinclair's wing tie down kit. http://cumulus-soaring.com/jj.htm

It is a piece of stiff and padded aluminum that captures the trailing edge of the wing and then has a strap that goes around the leading edge and from there to a ground stake. It works great.

It should work on your 18m tips as long as the ailerons do not go all the way to the very wing tip. For a "belts and braces" approach, add a wing stand.

My $0.02. John

[kirk.stant]

Cheap rudder lock: wing tape on BOTH sides of the rudder hinge. Just make sure you remember to take it off before flying!

Kirk
66

[Jim White[_3_]]

At 15:32 12 May 2016, kirk.stant wrote:
>Cheap rudder lock: wing tape on BOTH sides of the rudder hinge. Just make
>sure you remember to take it off before flying!
>
>Kirk
>66
>
What kind of weather are you expecting? If the expected gusts are large
enough to lift your glider off a pair of firmly wedged wing stands, I would
de-rig and tuck it away safely in its trailer.

Jim

[Martin Gregorie[_5_]]

On Wed, 11 May 2016 19:49:17 -0700, resigler wrote:

> Hi Martin. I'm very interested in seeing some pics of the tie down you
> describe. I'm having a hard time visualizing so a pic will be quite
> helpful. My Libelle has the Striefeneder winglets - will your kit work
> with those too I wonder? Thanks.
>
> Robert
>
Here's the link: http://www.gregorie.org/gliding/tie-down

The photos should make the way they work clearer as well as showing the
impact of my model flying background when it came to making a male mould
for the tip fittings.

You may be able to use a similar approach: since the winglets are
removable, you could either design the tie-downs to be used with the
winglets removed (and designed to fit a squared-off tip), or treat the
carbon mouldings as effectively a V-shape that fits over the TE, rather
like giant aileron locks, but with the outer edges curling upward to fit
the winglet fairing. This would mean that the tie-downs can't slide
inward along the wing, but may mean that they need to be under the winglet
covers to keep rain from getting inside them. That wouldn't hurt the tie-
downs but could lead to water pooling between the foam rubber and the
wing surface.


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