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Old July 20th 17, 03:48 PM posted to rec.aviation.soaring
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Default Flap performance

On Tuesday, July 18, 2017 at 11:59:05 PM UTC-7, Just Me wrote:
I'm considering purchasing a Ventus B. I'm aware of the "stability" issues, although some the extent of the stability issue seems to vary from plane to plane and pilot to pilot. I've talked to some people who say its not a big deal, and others who say its problematic. It's hard for me to know what to expect.

However, I was discussing flaps with a flight instructor and a question came up: How does a Ventus in neutral flaps compare to a Discus (I'm aware of the handling difference)? If you are in competition, flying a flapped ships, against other flapped ships, you better be an expert with the flaps. But if you are doing cross country work, are flaps essentially just an asset that is optionally available to allow you to slow down in a thermal or speed up in cruise.

He asserted that the Discus wing was considerably more advanced than the Ventus wing, and that you had to effectively use the flaps or you were actually better off (performance wise) with the Discus -- ie if you aren't flying a lot, you should stay away from flaps.

Can anyone compare the performance of a Discus to a Ventus, or better yet, does anyone have polars for a Discus and a Ventus (as a function of flap setting)?

FWIW, I have about 200 hours, and have flown flapped ships, including a 301 Libelle and a Janus -- as well as a wide variety of other non-flapped ships.


I think I can help with your question. I have 4 years in a Ventus B no winglets, got in it with about 1000 hours, much of that as a ride pilot. I've flown a Janus, Libelle 201, and owned a Kestrel 17 for a few years before the Ventus. I have not flown a Discus or 301, but I have a couple hundred hours in an LS-4.

The Janus and Kestrel are complete puppy dogs compared to the B no winglets.. I wouldn't use those gliders as any determining factor, other than whether you like using flaps or not. Whether you want flaps or you want a Ventus B are two very different questions. More important with the Ventus, do you have good glide path control on final? It has dive brakes and you don't want to pull them in at all on final when close to the ground. They are very effective though so it's easy to stay high and pull more and more in (if you have to, usually its easy for me to estimate correctly) towards touchdown. I love the glider on final, it's super stable and has a very wide glide angle range.

I love my Ventus because I cannot afford a V2, 27, etc. I'm hoping to get into a C model at some point... On a strong day with reasonably smooth thermals it is shockingly fast and a blast to fly. On a strong and turbulent day it is still fast, but can completely thrash me in about 4 hours so that my motivation to maximize the day is diminished considerably. Just flying the glider, stick and rudder, on those days takes a lot (too much) of your mental workload, even when it's going on in the background. You notice it after a few hours.
Other than that I love everything about the glider. Auto hookups, water tanks, I love the dive brakes/landing flaps (+2) on final, and the price is great because of the (somewhat) undeserved handling reputation.

Is there any way you can fly a Ventus B before buying? And fly it on a turbulent day.

WHERE are you going to fly it? In a place with strong lift/turbulence or gentle If gentle I say go for it, if not then you have some things to consider. Ben mentions flying his a 50-60 kts during glides. I've never flown mine below 65 in a glide? I fly in the western US. In Oregon where the thermals are almost always smooth and less powerful, it is the perfect glider for me. In Nevada on a turbulent day, the glider can be alot of work. I heard people say that you can't take your hand off the stick and I couldn't believe that, but it's essentially true. It will wander in pitch so much that you have to have one hand at least steadying the stick.

With half water, about 1000 pounds auw. it wants to go 85+. That to me is a great glider. Now you get to decide...