VIA: http://www.paraglidingforum.com/viewtopic.php?t=24784 (http://www.paraglidingforum.com/viewtopic.php?t=24784)
MENTOR-MANIA A Real Success Story
Frankly speaking, we have to admit that we started this season with pretty high expectations. We knew that the MENTOR 2 had the potential to be a real winner, but one never knows and gut feelings can easily go wrong.
Today we know for sure: it is a real success story. The EN B- wing is breaking all records, in terms of sales as well as in Cross Country flying.
When it comes to marketing, all paraglider manufacturers promote their wings with the same magic formula: “great performance, nice handling, and high safety”. We too! So aren’t there any differences between all the brands? One difference from NOVA to many others might be that we focus a lot on the practical suitability of our new models. We want paragliders which not only perform in the “lab”, but also in real life. Our main test area above Achensee (Tyrol) features strong thermals, high wind speeds, and plenty of lee turbulences – a great place for testing wings in real life flying. It’s not just about how a new model behaves in case of a collapse (certification). It also matters, how easily it collapses and what’s the benefit of a high max speed if you don’t dare to push the speed bar…?!
Our team is proud and satisfied to see that the MENTOR 2 is doing what we were hoping for. Looking at the worldwide standard class ranking of www.XContest.org (http://www.XContest.org) , you can see the top 5 pilots flying NOVA. And you can find 41 NOVA-pilots among the top 50 (yet,some of them are older designs like MENTOR 1 or ORYX) and 18 of the first 19 are NOVA paragliders. Numbers that acknowledge our work! (from May 27th, 2011)
Furthermore, we receive the comments from highly experienced pilots with EN D or even open class wings. After flying in comparison with the MENTOR 2, they disbelievingly relate that the “fat” (because of its low aspect ratio) MENTOR 2 has an unbelievable glide, even on the speed bar! And many “Joe Average pilots” did a test flight with the MENTOR to find out clearly: “Yes, this is going to be my next wing!”
MENTOR 2 The Pros' Real-Life Feedback
The XC season 2011 has seen various very long flights and several MENTOR 2 pilots were able to log 200+ km, which is not so bad for an EN B-wing. But even if these pilots are world class XC-pilots who took advantage of great weather conditions, the number of 200+ km flights is surprisingly high! So we asked some of these pilots what they think about the MENTOR 2 and why it is so suitable as an XC wing… …
Rolf von Arx, 46, flying since 1989, social worker in Lucerne (CH): “The MENTOR 2 is very pitch-stable and handles every kind of thermal well and with a certain edge. I enjoy the direct, yet never nervous handling, which allows me to climb very efficiently. Another strength is the accelerated glide. It is so good that I can even keep up with an EN-D wing. I also appreciate the very high stability of the MENTOR 2. It is stable enough to use the speed bar even in thermal conditions. I think the most unique feature is the combination of high performance and a phenomenal docility!” Check his 209 km FAI triangle.
Johann Tockner, 42, engineer, flying for 24 years (AUT): “I would say that the MENTOR 2 is particularly well-balanced. Its performance is not only defined by its L/D in calm air, but more by its high efficiency in all kinds of flying. I really get exited about its calmness while flying in strong thermals. Thus, I can focus on searching for the best climb. Moreover, the MENTOR 2 does not lever, not even in wind-disturbed thermals. The canopy stays perfectly controllable. Some of my long XC flights I did together with pilots under EN-D wings and we traversed wide valley wing tip to wing tip. Surprisingly, we are unable to see any relevant disadvantages for the MENTOR 2 – whether calm or moving air, on trim or accelerated. The MENTOR 2 has not the highest max speed, but this can be compensated due to its high stability even when approaching a strong thermal from the leeside! I dare to use the speed a lot while feeling absolutely safe!” 230 km FAI, 218 km FAI.
Robert Muggli, paragliding instructor (www.alpina-paragliding.ch (http://www.alpina-paragliding.ch)), flying since 1987 (CH): "It's all about the right mix! The MENTOR 2 is climbing really well – especially in narrow thermals. The polar is really flat! Even with 80% speed bar it still gliding very well (I am not that much interested in the L/D at trim speed) and with an uncomparable stability – even at high speed. Generally, its character is clear and predictable. Overall I like the handling and enjoy the flying. I simply feel well. For the MENTOR 3 I would like have a higher maximum speed (about 2 or 3 km/h more) and a little bit less brake pressure!” 240 km FAI, 225 km FAI
Peter Kleimann, 32, physician, flying since 2008 (CH): “The MENTOR 2 climbs as well in soft thermals as other paragliders do. In strong thermals it is awesome! I can turn it on the wing tip and circling upwards like a corkscrew and passing the others on the inside (despite a rather strong self-righting – I think I should try the FACTOR). Full speed is no problem. It stays very stable and if I should slow down a bit, it tells me early enough. Since the MENTOR 2 shows a well-adjusted pitch dampening, XC-flying is really relaxed, while I can still do nice wingovers. In addition to this, the MENTOR 2 has a very defined stall and collapse behavior, again with early warning to the pilot. Maybe that’s the reason why I have stayed entirely free from collapses on all the long flights and why I don’t need pay attention to the canopy at all. After one of the Fanas-days, an R10 pilot approached me and said (quite exhausted) that he would have liked to fly a MENTOR 2, while I’ve always felt really fine during the entire day. Besides, I am really pleased by the finish and manufacturing quality. Trying to find something to improve: a little bit less weight.” 207 km FAI , 210 km flat
TEST PILOTS' CORNER About the Lift/Drag Ratio
Under this headline our test pilots give insight views into their daily work and advise about flying physics, flying techniques, manoeuvres and wing certifications. Today, Pipo Medicus writes about the Lift/Drag Ratio.
“Previously there have been lots of discussions about the L/D. Often mentioned: Some paragliders are able to glide really well against a headwind. Others prefer calm air. And then, there are models performing best in turbulent conditions. In the following, we would like to get a close look at the L/D, explain how we optimize our wings for real life use and why we still prefer to not speak about the absolute L/D numbers.
As you probably already know, the lift/drag ratio is the proportion between forward motion and altitude lost. Needless to say that this for completely calm air!
Assumed that two paragliders have an identical L/D at trim speed in the laboratory circumstances mentioned above. Next assumption is that they still perform the same when accelerating about 10km/h. What would change, if both wings would glide next to each other in a laminar headwind of 20km/h? Against a popular erroneous belief, nothing is going to change at all! Both paragliders are still flying with the same speed and are going to sink at the same rate.
However, in turbulent air the situation can change. To optimize the L/D in moved air for everyday life during XC flights, we take particularly care of three criteria:
1.) The canopy has to be stable: It should deform in bumpy conditions as little as possible, with or without speed bar. Otherwise it would loose its aerodynamic shape!
2.) The wing should not pitch too much or too little: Any back and forward movement leads to a decrease in performance. However, we’ve had the experience that a canopy with extremely high pitch stability is as willing to take smaller “lifts” as canopies with a lower pitch stability. It’s the right balance that counts!
3.) The pilot has to feel at ease: If a pilot is surprised by frequent big collapses when using the speed bar, he will more tentatively use it in the future… Again it’s the balance of a sufficient amount of feedback without getting nervous. Especially for long and effortless XC flights, the right amount of dampening is crucial. The pilot should not be distracted by permanent corrections of the wing.
If a paraglider does not perform in calm air, it will neither do well in turbulent air. That’s why we spend great effort to optimize the L/D in calm conditions.
Finally, we want to explain why we still do not publish L/D figures. Typically, a size „L“ wing will always perform better than the same model in size XS. Concerning pilot and harness it’s vice versa: small pilots in a small harness have less aerodynamic drag and are therefore better. So the best L/D would result from a very small pilot with a pod harness who carries enough weight to fly an „L“ size wing.
A MENTOR 2 in such a configuration would deliver an L/D of over 10. With the same pilot on a MENTOR 2 in „S“ with a standard harness in upright position the L/D would decrease below 9. Is the glide ratio of MENTOR 2 now more than 10, or less than 9? Neither: if one were to fly the glider with a streamlined lead weight, the Lift/drag ratio would exceed 1:11!
You can see that it’s actually pointless to speak of an absolute L/D of a particular model. That’s exactly why we hesitate to publish L/D figures in our technical data. But you can be sure that we undertake every effort to make NOVA wings perform well not only in simulations (computational fluid dynamics http://www.nova-wings.com/english/info_zone/cfd.html (http://www.nova-wings.com/english/info_zone/cfd.html)) but also in real „real life” conditions.”