Or: Are we manoeuvring ourselves into a dead end?

We’d like to hear your views.

I received the following mail and thought long and hard about what I was going to do about it.
But see for yourself:

Dear Mr Weber,

in light of the French study, wouldn’t it be an idea to offer a glider type for less testosterone? A glider type that admittedly doesn’t reach the performance of gliders with a wing loading the other side of 40kg/m² in great conditions, but which, for exactly that reason, may be available to “normal” pilots on those kind of days, and which climbs well in weak thermals due to its lower wing loading – in conditions when the “top people” can only fly around the thermals and lose out. A type that can be landed at 27kts on a sprung and at least 3/4 retractable main wheel, thus reducing the risk of damage and injury in a field landing in a much more primitive way than by fitting an engine.

Such a glider type doesn’t need to be a primitive thing like the Czech Banjo, but a wing area of approx. 11m² at 15m wing span, a thicker and more curved profile (approx. 16%) and the use of mainly carbon fibre could make an empty weight of 310lb (140kg) with a vne of approx. 80kts (150kph) a real possibility. Designing a glider like this would present a totally different challenge to building the heavy high-performance ships. To achieve such a low wing loading (approx. 22kg/m²), slightly different profiles will be necessary, maybe one of the Eppler profiles would be suitable – the fs-24 profile was not bad, after all. (And I would also have an idea for a different, lighter, spar construction). An impeccable finish is probably even more challenging and important to achieve on such a light aircraft than on one of its heavier colleagues.

I don’t think that your company would lower its standards if you started building this kind of glider. Quite the opposite, it would be a great addition to the product range.
In brief: a glider for the majority of pilots!

I believe that club gliders should not just always be basic versions of competition glider types, they should not aim to meet lower expectations, but instead they should be able to provide a satisfying gliding experience in weaker weather conditions and thus enable pilots to do more flights, more hours, per flight as well as over the whole year! It was possible, after all, to carry out thermal cross-country flights in December with the second version of the Windspiel (78kg). Wouldn’t it be great if this were possible again, and not just with an L/D of 22 then, and (allegedly) 28 today, like the Banjo, but with an L/D of 37, like the fs-24 Phönix (admittedly with 16 m wing span).

And even if people can’t do without the adrenalin and testosterone-rich advertising effect of record flights and competitions: Why not organise a weak weather comp in the Northern German flatlands in mid October? Whoever would win such a comp would do so because of the nature of their mostly second-hand gliders rather than any high-performance ship, which would be too heavy for this kind of event. In addition, there are always days in autumn – from the end of September – where there are cloud streets building over the (western part of the) Mediterranean as the sea is still warm and the air above it therefore generally unstable. A lightweight, high-performance glider designed for weak weather conditions should be able to put those to good use! How does that sound – to Mallorca in a glider? The first 300km flight over open water?

In the same way as the DG brand has a Mercedes-like reputation, and LS is seen as the Porsche equivalent of the gliding world, surely there must be a niche for something similar to the (technically not necessarily simple) brand VW. That would be a big step towards getting an ex-glider pilot like me back into the movement.

(If you then fitted a twin undercarriage and a winch that’s remotely controlled from the glider so that one man can launch his glider without any help, you would create the perfect situation for the ex-pilots (who may be more suitable as role models) who want to fly again but also want to spend time with their wife and children, and who don’t want to be subtly kicked out by the “ambitious pilots” (who often have less responsibility for others) via family-unfriendly morning briefings.

There is always a close relation between the fleet and social network in a club. You could open a very important door there.

Oh, I would be delighted, I would almost love to help design it.

Kind regards,

Klaus Kleinhoff

---

Here my quick reply:

Dear Mr Kleinhoff,

your detailed mail is, as ever, a joy to read.

My response to your suggestions is that the whole thing is a non-starter, for the simple reason that it is not cheaper to build a “bad” glider than a “good” one.
An alternative may be to spend €15,000 (or £10,000 / $20,000) on a good DG-100 or LS1f – they can give you joy for many decades.

Another option would be a UL glider like e.g. the “Apis”. It is light and easy to rig, but it doesn’t fit into the German certification regulations. For that the MTOW of 120kg (265lb) would have to be increased a little.

Regarding your mail – I would love to open this subject up for discussion. Believe me, I don’t fancy building gliders which are mainly aimed at the few competition pilots and only moderately suitable for the masses. To kick-start that discussion it would really be worth publishing a new article.

Should I?

---

Dear Mr Weber,

for heaven’s sake, no, I don’t want you to build a cheap, and by no means a bad glider.
What I had in mind would not be much cheaper than a 15m LS8 or a 15m DG, because only the material costs will be slightly lower (due to less mass), but not the labour cost. You should definitely use (expensive) carbon fibre – indeed in the wing you should use it nearly exclusively. And of course it should be a non-strutted wing.

My idea is not about a different financial budget but a different time budget. Someone who is highly flexible in their job (even if it’s only because they have to be, in order to feed and educate a bunch of children), has to be less flexible in their spare time, whether they like it or not. When such pilots have some spare time, they probably want to go and fly – instead of waiting for the “stonking thermal days”, which are rather rare and tend to happen exactly during the annual family holiday, or when they are away on business. Or when the “better” fellow club member has taken the glider away on a “bigger” task. The most likely time they will be able to fly will probably be later in the afternoon/evening, but the average, competition-tuned glider will not be able to find sufficient lift.

If such a glider were flown by club members for about 400 instead of, say, 150 hours per year then it would actually be cheaper to run even if it’s only maybe 15% cheaper to buy, as the cost of interest to be paid on the money raised for its purchase is less if you see it in relation to the glider’s utilisation.

Because of the much lighter wings (preferably split into three sections), frequent rigging and derigging would cause much less back pain. This would be of interest to private pilots as they would not have to find a hangar space, which in turn eliminates the risk of hangar rash.

Please feel free to publish this, in fact I’d be glad if I may have contributed just a little bit to a new development.

Kind regards,

Klaus Kleinhoff

---

What are your thoughts on this?

To our surprise, the study mentioned earlier indeed revealed that the vast majority of glider pilots are not interested in competition flying. (In the three age sections, 79%, 88% and 78% did not want to fly in competitions!) If this is the case, why do we build such narrow cockpits which are supposed to reduce drag by tiny, immeasurable percentages, but stop slightly bigger club members from flying those gliders? Surely this doesn’t help ensure the future of our sport either!
I can tell you why we do it:

“Win on Sunday, sell on Monday!” – it seems that the competition results are an important criterion for a lot of potential buyers after all, and the “better” fellow pilots mentioned above often seem to be the decision makers in clubs. All this despite the fact that the performance of all modern gliders is so similar that the competition results are almost entirely down to the pilots’ skills and a bit of luck!

But what do you think? Please write your opinion to

weber@dg-flugzeugbau.de

– friedel weber –

Translation: Claudia Büngen

---

Your Comments:

Dear Mr Weber,

I think this is an interesting discussion.  I agree with Mr. Kleinhoff’s basic proposition that there should be a glider for maximum pleasure for the typical pilot rather than maximum performance for the minority of competition pilots. I do not agree on his proposal for the type of glider to do this and I can understand your initial response.

I think the PW-5 gives a good example. This was designed based on mistaken
logic:

• All pilots want to fly in competitions – right?
• The cost of top-performance gliders is too high for many pilots.
• So let’s build a low-cost glider competition glider of lower performance.
• The lower performance does not matter since all pilots will be
  competing with the same glider.

The PW-5 was a failure because pilots could get better performance and more FUN by buying an old 15m glider. Most pilots did not really want to take part in competitions anyway, so why pay more to downgrade?

I therefore think that Mr. Kleinhoff’s basic idea is good (design something for the vast majority of real pilots), but his solution would fall into the “PW-5 trap” for a manufacturer. People would instead buy used gliders to get higher performance at lower cost. My proposal is different.

The reality is that the vast majority of pilots do NOT fly in competitions (you quote about 80%, I have seen higher figures and at my club it is 100%). Gliding is also a sport which hooks people for life. It is a great sport to enjoy in your retirement.  At many clubs a lot of the members are aged over 55 and hope to fly for 20 years more. I do not know if you have researched the median age of DG owners but I suspect it is between 55 and 60.  The design should also recognise that for this age group comfort and ease of use are important.

I am the owner of a DG300 with winglets and love it. I could afford to buy a new DG808S but do not intend to because the improvements are not meaningful to me as a non-competition pilot. I do attempt cross-country flights but for me there is as much pleasure and challenge in trying a 300km flight in a 41:1 glider as a 400km flight in a 50:1 glider.

My proposal is for a glider which gives greater gliding pleasure, only part of which is good performance. My target design would be based on the 808 series.

Let us start with the cockpit. The DG300 has an excellent seating position and visibility. For high wave flights the big canopy keeps your feet warm in the sunshine.  You should NEVER change that. However the cockpit is not wide enough for comfort (and I am not a large person). An extra 50mm in width would be good, 100mm excellent.  There would be a performance penalty but read my next point.

If you forget about competitions you need not fit into a 15m or 18m class. You can make the wings long enough to do the job. I would make them the length necessary to give a 48:1 performance despite the wider cockpit.  The wings should not be longer than necessary in order to reduce the risk of a ground-loop in field landings.  Hopefully something like 17 to 18 metres with winglets would do it. Apart from competitions and record-breaking, 48:1 is good enough and gives an incentive to people to buy this instead of older 15m gliders (35 to 40:1).

The wings should have a parting just outboard of the airbrakes.  At present the parting is done to have the choice of 15m or 18m classes. For non-competition pilots this is of no importance.  For this glider the purpose of the parting is just for ease of rigging. It is important to reduce the weigh of each section to be carried.  Your testing team for rigging should be two small people both aged 70!  I am not 70 yet but one day I hope to be and also hope to still be flying.

For lower and safer speeds for field landings perhaps simple landing flaps could be used.  These would have only two settings – “Flying” and “Take-off/Landing”.  These could be linked to the wheel up/down mechanism to be less complex and safer in operation.

Taping the joints after rigging is easy on the tail, winglets, and wing tops. For the underside of the wings it means lying on perhaps cold wet ground and stretching in an uncomfortable position. It should be technically possible to design wings which do not need taping at the roots.  For example, what about an inflatable rubber seal which can be pumped up after rigging? This would seal the joint even when the wings flex in flight.  Even something which just seals the underside of the wing root would be very useful.

To keep the cost down no water bags need be installed except perhaps as an optional extra.  In Northern Europe conditions are rarely good enough to justify the time and trouble to use them except for competition pilots for whom every minute counts.

There is a need to urinate on longer flights yet the systems provided in gliders are still primitive.  Tubes to the outside of the glider to dispose of urine in flight can spray corrosive liquid under the glider and can freeze up on high-altitude flights Quite good solutions now exist for people who are wheel-chair users.  They can use well-designed systems to pee into an expanding bag attached to their leg or under the wheelchair. It would require very little space to make a rigid tank of 3 to 4 litres capacity under the cockpit floor. Inside this can be a rubber bag which can be emptied and hygienically washed after the flight. I have made my own system which fits in a box under the seat and works very well. If it is filled during a very very long flight it can be switched over to the standard system.

The NOAH system is excellent to assist exit from the glider in an emergency. It would be good also to have a system to assist getting out of the glider in the ordinary way when it is NOT an emergency. I have no problems myself, but I do know people who have difficulty getting out of a DG cockpit.  I am thinking of a system to raise the body level with the edge of the cockpit before exit.  This could be quite simple.  It is easy to use the elbows to raise and lower the body repeatedly to allow a spring-loaded seat to gradually rise and lock at each stage.  Obviously it will need some safety lock in the low position in case of negative G!  The spring to raise the seat need only be a weak one to raise just weight of the seat and cushion. The mechanism can be locked down unless the wheel is down.

In summary this glider would aim to give the best combination of good performance, fun, comfort, safety, and ease of use.  It seems odd to me that the single seat DG and LS models and those of the other manufacturers all target the competition pilots and not the large majority of real pilots.

It is as if the entire car industry made only Porsches.

Brian Brown.

---

Greetings from Canada!

Personally I am all for a lighter, less expensive glider with lower performance. Take a look at something like the SZD junior. Its light and easy to rig. An absolute joy to fly. Rugged. 35:1 It is also reasonably priced.

I am a new cross country pilot. I enjoy the CHALLENGE and ADVENTURE of soaring. When I do my 300km this summer, I plan to do it in the 35:1 junior, or maybe the PW-5. I view the LS-4 as “too easy”.

I fly for ME. In my eyes, flying 300km in a 35:1 pure glider is as much an accomplishment as 500km at 50:1 with a safety net.

DG needs to make a glider for the working man!

K.

May I repeat:
It is not cheaper to build a glider with a worse glide ratio as with a better one.

I have given detailed explanations to this topic here:

---

Dear mr. Weber,

I read with much interest every new idea, particularly if it pertains to the gliding world.

I must say that my budget doesn’t allow me to buy a new glider, and so I am not really interested in the future directions that the new designs will take.

However one thing struck me in your answer: “Win Sunday, sell Monday””.

Well, it seems to me that the DG gliders don’t really need the competitions to sell.

Honestly speaking, apart from the club class, I don’t see many DG gliders in competitions.

As a matter of fact, DG can feel free from the competition constraints.

I don’t know if people really want gliders made for the weak days, or instead they like high performance gliders, but I feel that DG should disregard the competition requirements, and focus on the man behind the stick needs.

That has always been DG trademark, and I think that this attention to the pilot above all has gained the DG its own market share.

Best regards,

Marco Bertoluzza.

---

Dear Mr. Weber,

I fully understand your points made and I am in the fortunate position to own a recently built DG-808C Competition, but I also fly
club gliders of the Grob variety e.g. G-102s and G-103s.
In the early 1970s Grob had the foresight to design and build a fleet of gliders at reasonable costs to the purchasers with good performance. These gliders were bought in very large quantities at the time and many are still flying in a variety of clubs around the world. In other words, Grob found the sweet spot in what the clubs were looking for.

Unfortunatedly since then, the clubs, mainly in Germany I might say, have upped the expectations and decided that the Grobs were not good enough for them and started to go for the DGs, Schempp-Hirths, etc and stopped buying the Grobs, who in turn stopped production.

So, to me the question is: Are the clubs willing to buy, what I would call, a medium performance, easy to assemble and operate, modern glider in the quantities needed to get the costs significantly lower than what a modern “Standard and/or 15m Class Glider” would cost? As long as this is not the case and with the attitude the clubs have, they will go for the higher performance glider anytime, in particular where there is Government funding available like in Germany, France and other countries.

The clubs I am flying with in Canada use  Blanik L-33s, Grob 102s as entry level single seaters and then DG-300s, ASW24s etc and the utilization of the entry level fleet is less than half from the higher level performance ones for a number of reasons, but the main one being, that the pilots want to go as fast as possible to the better performance fleet, which I presume is only human.

Unfortunatedly in summary, I don’t see an easy solution, if one at all developing, as long as the drive by clubs and individuals is towards higher and higher performance. Only if there is a clear two tier market in terms of performance and clubs and individuals are happy to purchase and fly the lower tier performance gliders would it become viable for a company, like DG, to entertain coming out with such a glider.

So, I don’t see the gliding community going back to its roots!

Cheers, Hans Baeggli

---

Dear Mr. Weber,

It all depends on the market. I have worked with Fokker and seen an airplane factory go to waste amongst others due to bad market research.

Customers determine the products, not factories.

The current markets are well known, this is alledgedly a potential new market. But is  it; is a 15% price difference (if at all feasable) enough a reason for other pilots to buy gliders. One thing you don’t want to do is shift a part of your existing (high yield) market to a lesser yield market. If you should be able to make such a glider, what will be the price on the “used”-market after 10 years? Will the aircraft hold its value like the current aircraft or might the depreciation be a lot more than current gliders.

Well, this article is a kind of “market research” already .

Your posting let me ask:
What will happen with the value of Ultra-Light-Sailplanes after 20 years?
Nowadays a DG-400 built in 1985 is more expensive as when it was new!

In this viewpoint new gliders are not so expensive as they seem to be. Or do you have any other consumer product, which lasts for 20 years?

---

Hallo Friedel,

I think that the demand is for a modern replacement of the 1-26 (in North America) and the Prefect (Europe) niche in the club training environment.
In my club we have recently bought two L-33’s and they seem to fit that niche for our club, as well we have the DG300/303 on the HP end of the training schedule.
We tried the PW5 and that received mixed appreciation from members as it was cheaply built (as we found out when it crashed) and looked like a “horse designed by a committee”. The Russian attempt in this market at least looks like a glider with responsible curves etc.
The Schweitzer brothers had a series of performance standards in mind for club use and designed along those lines (2-22, 1-26, 1-23, 1-34, 2-32 etc). Maybe that is what your correspondent has in mind?
I wish you success in making wise decisions.

John

---

Hi,

There are, I think, a number of problems in designing a sailplane with a wide appeal.  These (purely my own views) are:

1)       There are a great number of reasonable performance sailplanes on the market that are not outrageously expensive and provide good rigging, maintenance and performance.  The LS4 and the DG-300 are the classic examples.  This means that the market share that a new glider that is not a high performance rocket is aiming for has a lot of competition.

2)       As you already point out – it is not much cheaper to produce a medium performance glider than it is to produce a higher performance one. Ok 15m ones have less materials than an 18m one and refining the aerodynamics may take slightly less time but the design and then certification time is roughly the same as is the labour to build (I guess).

3)       The people who fly them.  Everybody is getting bigger.  This, I think, may actually partly solve 1) as the number of people who can comfortably get into DG-300s, narrow fuselage Discuses and Ventuses is reducing.  This introduces some interesting design factors where cockpit loads are also going to go up.

So, what I would like to see in a new design:

1)       Very easy to rig.  Obviously complete auto connecting controls but also very light parts.  The point made by one of your correspondents about mid wing splits is very valid.

2)       Wide cockpits.  The bit of me that isn’t fat is my very broad shoulders and I am by no means unique in that.

3)       Heavier cockpit loads.  This will require different seat loads, harnesses and so on.  The population is getting heavier and we are increasingly seeing people that we cannot fit into a glider through load issues.

4)       3) will then require larger wing areas to give reasonable loadings and performance (bigger gliders).

5)       Performance.  In this I am not particularly bothered so long as it is at least in the 1:40 range.  I don’t fly comps but I do aspire to doing 500 km flights (I have my gold and am working on my diamond) and this is compatible with the aspirations of most solo pilots that I talk to.

6)       Repairable.  Some glass designs are complex and require difficult repairs.  The design should minimise this.

Something that meets this would probably have wide appeal to both private owners and clubs.  For what it’s worth I normally fly a very old Slingsby 19m Kestrel which (in the UK) is very cheap (less than 9,000 ukp) and has very good performance albeit a little poor if you try flying fast.  I love flying it because it satisfies 2, 5 and 6 and is cheap.  It is also a delight to fly.  If I could have 1 as well then I would be in heaven.

Hope this helps

Robin