Canopy & heat

[Philip Walker]

In May / June this year we took our Arcus to Jaca for a couple of weeks and had some serious issues with the canopy.

 

My father has owned several Duo Discus gliders, they all have had varying degrees of differential canopy expansion in heat resulting in problems closing the canopy. In some circumstances it has been impossible to close even when covered with the canopy cover and then wetted. During the order process for the Arcus we were assured by SHK that the new cockpit/canopy would deal with this problem. Our first full UK season in 2011 showed that this was not the case. The glider had a visit to Membury to be warmed up in the paint oven and the canopy trimmed. Although this helped it did not fully sort the problem. Eventually Steve Jones flew over from Membury on a hot humid day to carry out further canopy surgery which seemed to resolve the problem.

 

However in Jaca, despite using a silvered canopy cover and keeping the glider in the North hangar until ready to launch when we arrived at the launch point the canopy would not close – even with Pedro sitting on the nose and serious canopy cover wetting. We flew the next day by getting into the glider inside the hangar and being towed out to the launch point, silvered cover on the canopy, whilst sat inside like a pair of pr*tts. That flight ended with a fairly brisk descent from 3000m back to the airfield. Next day we went through the same procedure except that after 4-5 hours of flying the let down to circuit height was more gradual. After landing we could not open the canopy using ‘normal’ pressure, pulling harder resulted in the pin fracturing just forward of the front locating pin. The rear pins had released but with the front pin still attached we could not get out. Fortunately my father had a leatherman tool with pliers which enabled me to pull the pin and open the canopy.

 

This was reported to Schempp immediately together with a  photo of the broken connecting rod. We were advised that we could fly it with the front pin not engaged but decided this wasn’t a very good idea. A sleeved repair part arrived 9 days later as we were about to leave Santa Celia.

 

Since then the UK agent Steve Jones has been very good and has reset the fuselage pins which in what was left of the UK summer has proved to be effective. The response from SHK was very disappointing.

 

Any one else had any problems with heat & canopies? I know that there are Arcus’s in South Africa and the USA who must be getting much warmer weather on a continual basis?

 

Philip

 

 

[the_gle...@msn.com]

I know that my Arcus which was finished in Feb 2012 had significant work done to the canopy by the previous owner, but I don't know the details of what was done. It has seemed fine so far, but of course I have not experienced it in hot weather. Steve Jones told me that he is confident that he now knows how to deal with the apparently universal canopy issues. It is disappointing that the factory got this so wrong and then denied that they had done so!

 

Mark Burton

Flying Arcus M no 24, comp no 4M from Dunstable UK

[Barry]

I was worried about the same problem when I was flying in Uvalde for the Open Class Nationals. I made a cover that enclosed ice packs can be slipped into it. I put it under my normal cover until the start. Even with temps 112 Degrees F the canopy would close easily for  15-20 minutes. They are easy to make. We made a small one for a Nimbus have problems at the contest and it solved it first time he used it.

Barry 

[Mottley]

Hi all

I had the same problem with my Duo Discus

The following company made a canopy cover for me out

of the Hydroweave material.

http://www.cooltekstore.com/

Soaked the cover in Water and

put it over my normal cotton cover and the cooling worked perfectly

to keep the Canopy in good shape for the complete time the glider

was on the grid in Spain, South of France, Australia. Eventually

the Canopy settled down and I no longer required it.

I gave it to Uli Schwenk of Jaxida Covers in Germany for him to

evaluate for a possible mass production. However I have no idea

what he did with it. It may be useful to contact him and he may be

able to loan you my cover for you to try out.

Regards

Mottley

[John Iacobucci]

We are experiencing the same problem with our Arcus M canopy.  How difficult is it to reset the fuselage pins?  Or should we invest in a refrigerated canopy blanket as mentioned elsewhere in this topic blog? 

[Bruno Ramseyer]

Hi all

I had the same problem with my Duo Discus and a Blue Tinted Canopy as I already mentioned somewhere in this Forum

I got a Canopy Cover made up from a Material similar to Hyperkewl  http://www.techniche-intl.com/technologies/hyperkewl/

Powered by HyperKewl - TechNiche Intl. EVAPORATIVE COOLING HyperKewl™ Evaporative Cooling material is a unique fabric that absorbs and slowly releases water through evaporation. We look at this process as “super-charging” the bodies natural cooling process, thereby protecting the wearer against heat stress. www.techniche-intl.com

You soak this completely in water for a few minutes, then dry the inside and i used to place it over the normal grey canopy

cover as not to scratch the canopy as the inside was a plastic material. I used to place it on the glider in the morning before

the Sun started to Heat up. Even the outside Fabric Skin dried up very quickly the evaporative cooling worked for quite a few hours

because of the structure of the inside of this material. The closing the canopy before the flight was no longer a problem and the

Cockpit was also at an agreeable Temperature. However you had to be reasonably swift between taking off the cover and

closing the Canopy for Departure. You also needed somebody to take the cover away as you could not store it in the Cockpit.

Mine used to live in a Coolbox. So it worked well during my stays in the South of France (St. Auban) and Spain (Ocana) and Australia (Benalla)

After a few years the Canopy settled down and I gave the cover to Uli Schwenk of Jaxida Covers, as I thought he could be interested in

commercializing the product. No idea why this was not pursued as in my opinion it worked!!

Bruno

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[Mark Zivley]

I take a different approach. I prop my canopy open rather than cover it. My theory is that when the canopy is closed, no matter what cover you might use, you trap the heat inside the canopy and the temperature can get quite hot very quickly. Think about how quickly it gets hot under the canopy while waiting for the towplane to take up slack on a hot day! If you leave the canopy open, this avoids most of the expansion issue. True, this is not an attractive solution if it’s gusty or if there is a lot of dust, but otherwise it has worked well.

I took some 1/2” PVC and fittings and created a brace that attaches to the middle fuselage pin and connects to the mating hole on the canopy to prevent the canopy from an uncommanded closure. I cut the PVC into 3 equal length pieces so that the overall length is only a bit more than a foot long and it stows nicely in the baggage compartment.

[James Kellerman]

Before we sold the Arcus we had this recurring problem. We went to Terlet in Holland and they beautifully adjusted the canopy. Problem solved and never recurred

On Sat, 22 Sep 2018 at 03:32, Mark Zivley <markde...@gmail.com> wrote:

I take a different approach.  I prop my canopy open rather than cover it.  My theory is that when the canopy is closed, no matter what cover you might use, you trap the heat inside the canopy and the temperature can get quite hot very quickly.  Think about how quickly it gets hot under the canopy while waiting for the towplane to take up slack on a hot day!  If you leave the canopy open, this avoids most of the expansion issue.  True, this is not an attractive solution if it’s gusty or if there is a lot of dust, but otherwise it has worked well.

I took some 1/2” PVC and fittings and created a brace that attaches to the middle fuselage pin and connects to the mating hole on the canopy to prevent the canopy from an uncommanded closure.  I cut the PVC into 3 equal length pieces so that the overall length is only a bit more than a foot long and it stows nicely in the baggage compartment.

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