Schempp-Hirth | The New Ventus E and Visions for the Future

We talk to Tilo Holighaus about the Ventus E, FES retrofits for the Discus and Duo Discus and a possible increase in the wingspan of the Ventus.
Schempp-Hirth | The New Ventus E and Visions for the Future

Tilo Holighaus gives us an insight into the reorganization of the company. We talk about the philosophy behind the new Ventus E and about visions for the future. We meet Tilo in his office in Kirchheim/Teck.

Hello Tilo. Schempp-Hirth and the name Holighaus are inseparable. A few words about you?

My father Klaus Holighaus shaped the company as a designer, pilot, and businessman since the late 1960s. He brought many successful aircraft onto the market. When he died in an accident in 1994, it was clear to my mother Brigitte, my brother Ralf, and me that we wanted to take over responsibility for the company. After almost 30 years, we have now placed the operational work in new hands, but we are still wholeheartedly involved, for example in developing strategies with the new management or representing Schempp-Hirth to the outside world. We also like to share special occasions with the workforce, such as the recent delivery of our 400th Arcus. Commitment has already been passed on to the next generation - for example, my daughter Amelie is involved in social media.

The 400th Arcus

From the outside looking in, a lot is changing at the moment. Why don't you enlighten us first-hand?

For decades, we were a very close-knit team with the engineers from my father's time, i.e. Helmut Treiber, Ebi Schott, but especially Biggo Berger and many others. In the meantime, many of them have taken their well-deserved retirement and their experience cannot be replaced so easily. In many areas, we have been able to fill the gaps internally. However, a lot has changed in the meantime. Therefore, after much deliberation, we in the family decided to look externally to reposition the company for the future.

Have you found what you were looking for?

Yes, we are very happy about that. We have been able to bring a lot of people on board who complement Schempp-Hirth perfectly with new knowledge. With Sascha Costabel, for example, we have found someone with outstanding expertise in process optimization. At the very beginning of his career, he gained several years of experience in an LTB, which later led him into development and project management in the aviation sector. Many of his technical innovations and patents are now in use in large aircraft. And Sascha is ready to take on responsibility - a huge asset for us. As the new Managing Director, he will take over all of our operational activities. We have also gained extremely competent support in the commercial area with Frerk Frommholz.

What are the biggest challenges in restructuring?

First of all, the rapidly rising costs of materials and work are a major issue. Optimizing our purchasing to be sustainably prepared for the future is an enormous task.

Another point is the transfer of knowledge. As mentioned, the manufacturing processes worked well for a long time with our close-knit team. However, we allowed this enormous amount of knowledge to be anchored in individual heads. We are now working hard to bring knowledge from the heads into the company. In the meantime, we have already been able to optimize many structures and processes so that this know-how is accessible to everyone. For example, it is now easier to train new staff efficiently. At the same time, the aim was for every employee to be able to find themselves in this structure, see the sense in it, and enjoy working in a tidy atmosphere.

Internal restructuring often also has its negative sides.

Unfortunately, that's true. We were aware from the outset that not everyone would go along with this kind of restructuring. We have lost good people. Nevertheless, we have succeeded in attracting new knowledge and expertise to the company through a pleasing number of new good recruits, increasing the number of our employees and further qualifying them through numerous training courses. We have thus equipped ourselves for the future in the long term.

One question still needs to be asked here. With Michael Greiner, you now have someone on board who has already immortalized himself at Alexander Schleicher. What are his tasks with you?

Michael is another good example of bringing new and very valuable knowledge into the company. Having worked for a long time in research at the University of Stuttgart, old friendships from Akaflieg times with our engineering team around Christoph Wannemacher have brought one thing to another. As Michael recently told me, he simply wanted to put theory into practice again. In addition to other projects, he is currently working with Andreas Lutz on the electrical system of the new Ventus E.

So Michael is not directing the design of a new glider?

No. In general, we have always created new designs as a team, which has worked very well for us.

Let's move on to your latest project, the Ventus E. How did the idea come about?

In general, the path to electric flying was not an easy one. When the FES system from LZ-Design emerged, I was a fan right from the start. Nevertheless, I had to do a lot of convincing to implement the concept in our company. But I enjoyed it and as you can see from well over 100 FES aircraft from Schempp-Hirth: It was worth it! At some point, it was clear that an electric self-launcher would follow.

Have you been able to benefit from the experience of the FES system?

Indeed, we have. At first glance, the FES on the aircraft looks very simple, but actually, it is very complex. In contrast to a model airplane with a propeller in the nose, there were challenging issues such as safety, certification, and implementation to deal with. The result is a practical system for everyday flying. We benefit enormously from all this experience with the Ventus E.

The system was on display for the first time at the German Gliding Day. Does the motor concept come from your company?

No, we don't want to reinvent the wheel in electric gliding but rather concentrate on optimal integration into the Ventus. The drive concept comes from the company Solo, with whom we have been working closely for over 40 years - using their turbos and self-starters. There is a great deal of mutual trust here and we have closely followed the development of their electric drive concept. Now the time has come and the Ventus E builds on the experience that Solo has already gained over many years in the development of the system. The aim was to use as much of what was already available.

At first glance, the system resembles the JS3 RES.

That's partly true. The batteries are almost identical, but we position them differently. The engine is larger than in the JS3, as even the Ventus' sports fuselage offers more space. It is the same engine as in the AS33 Me and AS34 Me. There you can already see that it works well. For the controller, we rely on the controller originally designed by Solo with water cooling. We are focusing on using the space we have in the fuselage to optimize the system.

The propeller also looks larger than that of the competitors.

Exactly. The space in the fuselage is sufficient and the larger motor delivers enough torque. This gives us a very efficient system, which should also be noticeably quieter, as the propeller tips rotate more slowly.

You must have weighed up the pros and cons of the batteries in the fuselage.

Yes, but the decision was made fairly quickly. Thanks to our FES aircraft, we have a lot of experience with batteries in the fuselage and know that this is a very suitable concept.

We are convinced that the design of the Ventus is a quite suitable platform for an electric self-starter. It offers plenty of reserves in the structure and has slightly larger wings. The latter helps to achieve a wider range of wing loading and makes the glider lighter overall.

Larger wings are lighter than smaller ones?

This has to do with the structural design. The slightly greater height in the spar area means we can save a few rovings.

Interesting. Back to the batteries. More reserves in the structure mean no payload problems?

That is exactly the case. From a structural point of view, batteries would be better stored in the wing if you already had a problem with the payload. Fortunately, we don't have this problem with the Ventus thanks to the reserves. In addition, there are three major advantages of batteries in the fuselage:

  • You can take the batteries to a place where there are sockets. At the moment, an airfield rarely has the right infrastructure for electric gliders. This makes everyday life much easier, especially for traveling by glider.
  • The Ventus has always focused on great maneuverability, and this starts on the ground. True to the motto: "The best flight is the one you make", batteries in the fuselage promise easy handling and no heavy wings when rigging. 
  • Finally, the batteries can be installed pre-heated. This also guarantees great flying fun in winter, as batteries need a long time to cool down. I have flown at -8° on a slope and when I needed the FES after 5 hours, the batteries had still 10°. If the batteries were in the trailer overnight, they would be cold before take-off. As everyone knows: cold hurts capacity and battery life.

The Ventus offers plenty of space in the fuselage. Would even larger batteries be possible?

In general, yes, but we are deliberately not doing that at the moment. For the time being, we are relying on a tried-and-tested system and waiting to see what the future brings. You also have to bear in mind that larger batteries mean greater mass and therefore poorer handling, which is not the nature of our Ventus.

The larger wings seem to offer a great deal of leeway in terms of wing loading.

That's right. If you want to push it to the limit, you can only fly with one battery, but then you will no longer be able to self-launch. We are sure that the finished Ventus E will weigh well under 400 kg. With a wing area of 10.8 m². By using only one battery and a 70 kg pilot, we will be at about a 41 wing loading, which stands out in the electric self-launcher market, for sure.

Similar to other current 18m gliders, you focused on very high wing loading of around 60 for your Quintus (open class). Why are you now focusing on a larger wing area and slightly less wing loading?

In fact, the new Ventus looked quite different in our minds at first. Similar to the current 18 m competitors, with the smallest possible surfaces and a very high wing loading. We have a lot of fun thinking about new designs down to the smallest detail and analyzing all the backgrounds very carefully.

Of course, we also wanted a faster glider. But similar to the Arcus, we considered what makes the glider faster. We started by looking at the four common thermal models and analyzed all the IGC files from the last world championships and other competitions. The result: the thermal models are plausible in themselves, even if only three of them are relevant. But what is the situation in practice? Many components have simply not been taken into account so far. We have drawn our conclusions from this for the Ventus.

For example?

For example, existing thermal models simply do not take into account the cruise glides. So we developed our own models and integrated them into a cross-country speed analysis. There is simply more to a glider flight than flying fast between the thermals. The realization: If the design is only trimmed for wing loading, this also has disadvantages. To be more precise, the cross-country speed decreases again from a certain wing depth. Further details would go beyond the scope of this article. These considerations were part of a very extensive research project in cooperation with the University of Stuttgart.

Were you surprised by the result? Actually, the Ventus looked different in your mind.

Yes, it did. But above all, we were delighted. Because it opened up completely new possibilities for us. As already mentioned, a larger wing is somewhat lighter and brings reserves in wing loading. This means that a completely different performance is also available outside the best weather window. In combination with the aerodynamics, geometry, and rudder size, the larger wing gives the Ventus a recognizable good and safe handling and a much confirmed thermal sensitivity.

That sounds plausible. But if it gets really fast, will the Ventus have to make small compromises? I'm thinking of the World Championships in Hungary in 2022 or Uvalde next year.

We are very confident that the Ventus will perform well in Uvalde. Often, there are cloud streets and the proportion of great lines of lift is high. In Texas, the one or other weaker weather window also tends to creep in, which can be decisive for the competition. In Texas, the Ventus should be able to fully exploit its potential with its high bandwidth.

The 2022 World Championships in Hungary were special in many ways. First of all, we had weak statistics there. There were only a few Ventus in the field. In addition, there wasn't a single weak day where you had to be light.

I would like to get one thing off my chest at this point: The other manufacturers also build excellent airplanes. There are simply different philosophies when it comes to design. We are convinced that an aircraft should cover the widest possible range of weather. This range is also often decisive in competition.

A quick digression on your distinctive wing geometry. What advantages does it offer?

I think you're referring to the elliptical wings. Yes, in theory, they could indeed be better in nuances. The emphasis here is really on nuances. In practice, however, one advantage outweighs the others clearly: bent surfaces can be built and processed much more precisely. We attach great importance to delivering our gliders with precise aerodynamics, high profile fidelity, and the best possible surface quality. You have to remember: all manufacturers still sand by hand. Delivering similar quality with elliptical surfaces would be an enormous effort and hardly economical. With a twinkle in my eye: unfortunately, no one has invented the wing sanding machine yet.

Now we've drifted off a bit. Back to the new Ventus. Are you also thinking about offering the E system with the Performance fuselage?

Yes, we are considering that. It is clear that if the system fits into our small sports fuselage, it will also fit easily into the large one. However, we don't want to do too many projects at the same time and want to get the small fuselage into the air first. This will enable us to get our sporty competition version ready for self-launch and bring us into line with the AS 33 and JS3. Like other manufacturers, we think it's just great to have the opportunity to get into the air independently with the high-end competition racer.

Where will the Ventus E fit into your portfolio in terms of price?

We can't say for sure at the moment. We estimate that the Ventus E will cost about the same as the Ventus 3M. The construction process for the electrical system is similarly complex and the components are unfortunately expensive.

But one thing is clear and we can speak from experience with our FES aircraft: The electrical system is less susceptible and maintenance costs are kept within reasonable limits.

Finally, a few questions about the future. Will the Discus 2c and DuoDiscus X(L) soon be able to be retrofitted with FES?

Yes, that is correct. We have made a major shift in our philosophy here. For a long time, we did not consider retrofitting aircraft with engines that were not already prepared for this.

Does this mean that these aircraft can also be retrofitted without an engine box?

Indeed. We no longer shy away from any expense here. Unfortunately, we have now realized that these aircraft can no longer be sold at a significantly lower price than our models with flaps. This is also the reason why we have taken the Discus 2c out of production for the time being. The molds are still available and we could start again at any time. Unfortunately, we don't see any future for newly built Discus at the moment. We think this is a real shame, as we were very pleased to be able to serve the clubs with new aircraft. It is therefore all the more important to us that we continue to take good care of this clientele and modernize older aircraft. We have received a lot of positive feedback for this.

How is it with the Duo Discus?

The situation is somewhat different there. Here we have a lot of option holders whose interest we have asked. The overwhelmingly positive feedback has encouraged us to tackle the Duo-Discus FES project. We will therefore continue to produce this aircraft. We are also looking forward to retrofitting older Duos with FES.

Incidentally, we also offer modernization for other aircraft such as the Ventus 3T. For example, the Ventus E on the German Gliding Day was originally also a turbo.

Let's stick to the topic. DG is successfully running the Neo series. Do you also see the potential for new winglets, for example on the Discus?

Yes, definitely. However, this is not yet ready for discussion. But there is already good news for the old Arcus: in the future, it will be possible to carry out a facelift (new winglets, new tailplane, new canopy) like the new Arcus 20.

What about an Arcus FES?

This will be technically possible, for sure. We are still asking our customers about their interest in this.

Adam Wooley picked up a new tailplane from you before the World Championships in Narromine. Is the Ventus also getting a facelift? Will it grow beyond the 18m?

Good try, but I have to defuse this fact. The tailplane was not for Adam's Ventus 3, but for his old Ventus 2a.

We have already touched on the philosophy behind the Ventus. We have placed great emphasis on handling on the ground and in the air. Increasing the wingspan would mean an exponential increase in mass, which would not do justice to the Ventus' excellent handling.

Jonkers has launched the JS5. Schleicher is following up with the AS 35. In which areas are you thinking about new developments?

There are of course wishes here, but there are no concrete ideas at the moment. Developing a new open class would be very appealing to us. However, two main things are holding us back. The development of an open class is enormously expensive, but the market for it is quite small and the risk is correspondingly high. In addition, in my view, it is currently completely unclear where the Open Class is heading.

If we go back to the World Championships in Hungary, it was an outlier when the Open class flew 50 km more and 3 km/h faster than the 18m class. Counter-proposals for the competition rules have been discussed here for many years. For example, an "all day long distance task". In this case, an open class would look very different from a "best weather window" aircraft.

Do you already recognize trends?

We recognize that the influence of traditional competitions is diminishing. 10 to 15 years ago, everyone was still watching the big championships. Today, it's more the decentralized platforms like yours, for example. We notice this above all in our customers and which aircraft they ask for.

And I would see that much less as fatal than as an opportunity. Decentralized flying and new competition concepts are developing extremely dynamically, with a focus on fun and experience. I am sure that many more exciting forms of competition will develop from this.

For example, hybrid gliding?

Exactly. The concept has not yet arrived in many people's minds. For many, the motto is engine on, flight off. But the idea behind it is engine on, experience on. An electric motor simply extends the range and extends the season. The threshold for rigging and going flying and experiencing something is much lower, even in marginal weather.

How you fly with it also still needs to be established. In contrast to the combustion engine, it makes perfect sense to start the engine at an altitude of 500 or 1000 meters to get to the next weather window safely and relaxed, where a new adventure awaits. In general, a major rethink is still required here, but we are convinced that a lot of people will still enjoy this type of flying.

Is that also your vision for the future?

Yes, that is part of it. In general, we see great potential for gliding in terms of sustainability. Gliding has always been a clean sport and this will only increase with electric gliders. We are hopeful that we can jump on this bandwagon to lower the access threshold for the general public and make the sport accessible to more people through our gliders and get "pedestrians" excited about our wonderful sport.

Tilo, thank you for the interesting interview.

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