Discus CS vs LS6

[Varun Gite]

Opinions on Discus CS vs LS6? How to they compare and which one is favorable for competition?

[R]

On Sunday, September 4, 2022 at 8:06:33 PM UTC-4, vgi...@groton.org wrote:
> Opinions on Discus CS vs LS6? How to they compare and which one is favorable for competition?

Both. The CS will allow you more choices being a non-flap glider. Neither is a top competitive glider when flown by a beginner, but both are a great choice to hone your skills.A good way to start.
Go with what attracts you the most.

R

[Jay Campbell]

Other considerations? I have a 24 year-old CS and the gel-coat is virtually craze-free. I have no knowledge of the gelcoat quality of the LS6, but it would be something to look for before buying. Also, the LS-6 may have bags for water, depending on model; the integral tanks on the CS would seem a better choice.

[John Sinclair]

I have flown them both and would come down on the LS-6 side, all other considerations being equal. The 6 has a soft wing because the wing is not all carbon like the Discus. The soft wing gives a soft ride and allows you to feel the thermal. My suspicion was confirmed when a friend sold his 15 meter LS-6 and bought an LS-6/18 which is all carbon. He didn’t like the stiff wing on the 15/18 and ended up selling it and buying his LS-6 back!
JJ

[Hank Nixon]

On Sunday, September 4, 2022 at 8:06:33 PM UTC-4, privpilot06 wrote:
> Opinions on Discus CS vs LS6? How to they compare and which one is favorable for competition?

Both are excellent gliders with no real negative issues.
The Discus can be flown in Sports, Club, and Standard classes. The current US in Std handicap so it is competitive. It is and easy , forgiving glider, with very good performance. All controls are automatic.
The '6 was the bench mark of it's time. Great handling, excellent performance. Can be flown in Sports and Club. Manual control connections with not great access.
The '6 is more complex to fly, given flaps, but has a higher performance range. There is also an overhanging issue of manufacturer maintenance agreement which can make the cost of support and parts higher.
Deciding between 2 ships?.- The decision would probably be based upon the whole package- glider condition, equipment, trailer.
FWIW
UH

[Stéphane Vander Veken]

I'd say it very much depends on how serious you are about competition flying. Neither of these gliders is competitive in a modern high level competition in their original classes. However, the CS can be flown in the - handicapped - international Club class. At this moment, the LS-6 is not eligible for any international handicapped competition. I don't know about the USA "Sports class".

Another point is the fact that the CS is very sturdily built. The LS-6 however comes with caveats in the manual about being careful of not pressing too hard on the flaps and ailerons to avoid compromising the integrity of the structure. That can be a factor in your choice, if you think of leaving the glider in the open.

About wing flexibility: the CS indeed has a very hard wing, but some pilots prefer it that way, because you can feel every bump in the air. If you fly in a region with very strong and turbulent thermals, it can be a bit much, I think, unless you fly with ballast. I never flew a pure 15 m LS-6, but I find the flexibility of the 18 m wing just right, even without water.

[Eric Greenwell]

I suspect it's not the carbon that makes for a rougher ride, but the strength required for
the 18 configuration. That requirement leads to stronger, stiffer, heavier inboard panels
than needed for a 15 M configuration.

And, I've never figured how a soft, bump-absorbing wing let's you "feel the thermal"
better than a stiffer wing.

--
Eric Greenwell - USA
- "A Guide to Self-launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications

[andy l]

The Discus is not an all carbon wing. There are carbon rovings as the spar cap (and not carbon the full wing span) but the rest is glass.

[John Sinclair]

It’s not just carbon verses fiberglass that makes one wing stiff and another wing soft. Aspect ratio and thickness of the wing are big factors. The LS-6 has carbon spar caps, but the airfoil selected is quite thin allowing the wing to bend as it encounters changing conditions, which allows the pilot to feel how the ship is reacting to the air it is flying through! I call this, “feeling the thermal”! When flying a stiff wing in strong conditions, all I feel is the vertical changes, going from “hanging in the straps “ to “slamming down hard” in the seat………………..I’m feeling the seat and shoulder straps, not what the ship is doing in the air it’s encountering!
The first time I noticed the difference between a soft wing vs. a stiff wing was flying an ASW-20B. I had been flying an ASW -20 and loved the feel of the ship. The ASW-20B was made stronger so that it could carry more water, 1200 # vs. 1000# . The soft ride was gone!
JJ

[Christoph Barniske]

Some thoughts:

Pro Discus CS:
- automatic control hookups
- wider cockpit
- no service agreement needed for spare parts
- simple water filling procedures
- decent performance
- suitable for low-time pilots

Cons Discus CS:
- it's heavily optimized for simple production, not for quality (horizontal tail attachment prone to play, lift pins wear out)
- shorter cockpit
- a bit trickier to rig

Pro LS6:
- excellent handling characteristics
- well built (except for gelcoat quality)
- easy to rig
- quite long cockpit, very comfortable for regular sized European pilots
- better performance than Discus CS
- new winglets available for some versions, making it competitive in 15m class

Cons LS6:
- narrow cockpit
- manual control hookups (except LS6-c)
- service agreement needed for spare parts
- there are significant differences between the different versions; early versions require a damper in flap connection and may not be equipped with a tail tank