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windy day sailplane

Old 04-19-2009, 02:26 AM
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Default windy day sailplane

I've been thinking about getting a sailplane to fly at the field on days that the wind sock is standing straight out. is it possible to fly without having a hill to launch from? is high winds 20MPH+ good weather for a sailplane? I thought about using my magister as a tow plane for calm days.
Old 04-19-2009, 09:11 AM
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Default RE: windy day sailplane

Depends on the type of glider and site. There are three types of lift. Thermals, slope, and man made like electric motors. If you have a slope and 20mph wind that would be great. Thermals and 20mph is a no go. Motors work but then you have a powered plane...
Old 04-19-2009, 12:21 PM
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Default RE: windy day sailplane

Gliders can be flown in higher winds on flat land but it requires a different style of flying and some minor modifications.

Ballast is important. Really light sailplanes will be thrown around the sky by high winds. Ballast will make the wings use more energy from the wind in a positive manner instead of allowing it to toss your model around. The amount you use is going to depend on the wing style and airfoil of the plane. Keep in mind the construction of the wing as well. You're not going to want to overload the spar system and snap it in mid-air or on launch. You're going to want just enough weight to smooth the planes flight out and no more.

Airfoil is also going to be critical for this type of flying. A flat bottom is NOT what you want! They can be used but will require a lot more ballast to remain controllable. (Again don't overload the wing!) An airfoil that is semi-symmetrical will penetrate the wind better and still develop a good amount of lift while needing less ballast than the flat bottom one will.

Camber control of some type is also a major help. Flaps or flaperons are a great help for this type of flying. Drop the flaps a bit and point it into the wind and if you've got your setup dialed in it should climb like it was on an elevator. Also be sure you make your flaps so they can be reflexed upward in case you find yourself down wind and having to get back to your location to land. A touch of reflex and a little down trim will speed the model up and get you back to the field. With careful adjustment of the trims you can also hover and even fly backwards for short distances for something different to try. I've flown backwards and still gained altitude a few different times and it was very different. (Flaps down and a little up trim)

You'll still have to use some method to launch your plane but I'd stay away from towing in high winds. Winch or high start would be best. At least that way you only have one mode at risk instead of two.

I've done high wind flat land flying and it can be fun. You just have to set your plane up for it is all. You're not going to get the height you would in a good thermal but you can still fly.
Old 04-19-2009, 12:33 PM
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Default RE: windy day sailplane

Storm weather flying can be really exciting and at times very frustrating. But when it works it'll leave a grin on your face for weeks to come. I know because I had such a day one time.

I'm assuming that you're asking about flat land soaring since 20 mph is just getting up to normal for a lot of the slope flyers.

There's two options for getting the model into the air. Electric motor and prop or a short high start. If you go with electric you'll want to have spare prop blades and by all means use a folder. Even with that expect some bent shafts and possible fuselage nose during the inevitable hard arrivals. In some ways a short and stout high start'ish option may be a cleaner method. Something with 35'ish feet of surgical tubing and maybe 150 feet of line. The advantage of the high start option is that the model can be made more durable.

For the model I'd suggest something between the handlauch size of 60 inches and up to around 2 meters. To take advantage of the dynamic lift to be found in the sudden velocity shear effects of the typical stormy day turbulence you'll definetly want ailerons and elevator instead of rudder and elevator. This will also provide the more instant response needed to recover from all manner of sudden wind effects during launch and landing. Make the model itself reasonably light so it qualifies as a slightly heavy calm air model and provide some ability to add up to maybe 25 to 30% additional ballast. The airfoil doesn't need to be a symetrical aerobatic type but it should be one of the faster thermal soaring options. It should have a cleand "racy" airframe to minimize drag both so you can keep up a bit of speed but also to use the momentum to wedge the model up through the wind velocity shear effects instead of bleeding it off due to drag.

Flying such a model on stormy days isn't about circling with the thermals for the most part. If you try that you'll just end up WAAAAAAAaaaaaaayyyyyy downwind with no way to get home. Instead it's about watching how gulls and other birds work the velocity shear and turbulent rotors. In some cases you'll blend this stuff with slope soaring off the deflected wind from tree lines, buildings or slopes in the land. One time with an electric glider I got up where there was some oddball wave effect off a big cliff about 2 miles upwind and rode that wave for around 1/2 an hour following a harrowing 15 minute climb up to the wave on a combo of motor run and really short sharp bumpy thermals or rotor effects (it was a contest for longest flight of the day- terrible conditions, I won it but lost about a quart of liquid in nervous sweat ). Another option is to watch how birds will crab back and forth and suddenly turn into the wind and zoom up 40 feet. I flew in this manner on another storm day I got caught in. Managed to keep my 2 meter aileron equipped glider in the air for about 20 minutes of terror. I launched off a high start to around 300 feet. I descended to around 150 and the battle began. During the next 20 minutes I was up and down like an elevator between around 150 and 25 feet. It was just a case of crabbing back and forth across the wind and every time the upwind wingtip started to lift I'd turn into the wind and pull back slightly. When the energy from the gust seemed like it wasn't lifting the model anymore I'd push forward to avoid a stall and finish the turn to crab back on the other "tack". Not all of these lunges were turn reversals either. If the wind shear seemed better some of them were just a turn into the wind, rise and turn off again. Split second panic but I still remember it as one of the most exciting experiences of my entire flying hobby.

It's hard to lever yourself out of the house to go "gliding" when the weather looks like that. I'm just as easily diverted from it as anyone. But if you take up the challenge there's lots of excitement to be had in this sort of fringe activity.
Old 04-19-2009, 05:29 PM
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Default RE: windy day sailplane

Sportrider_fz6
Slope it on windy days.
I have found a handfull of slopes in the area (SW Mo.) all small for 48" flying wing or smaller, a few good for 2 meter planes. I hope to build a fish style foam glider such as LEG's Guppy for this kind of flying. IT seems the wind is blowing all the time any more.
Ozmo
Old 04-20-2009, 12:13 PM
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Default RE: windy day sailplane

BMathews, I'm mostly a sloper now days but OMG! Just reading that litlle right uup of yours and picturing it with all the gloomy clouds and windgusts......My hearts pounding!
Old 04-21-2009, 11:02 PM
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Default RE: windy day sailplane

sounds like it could be a fun challenge I'll have to give it a try. I have no glider experiance (unless you count an occational dead stick landing) I was thinking something like this [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXNH96&P=0]spirit elite[/link]
Old 04-22-2009, 11:05 AM
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Default RE: windy day sailplane

The Spirit Elite is a good plane to give the windy weather flying a try. Just build her light and make provisions for adding ballast. A 1/4- 20 threaded rod with a wing-nut mounted on the CG works great. Just melt down some lead and cast it into plates for your ballast. Draw a line from corner to corner to find the center of the plates and drill them at that point so they will not change the CG when you add them. (Always check the CG after adding ballast anyway to be safe)

The Elite uses pretty much the same wing as a regular poly Spirit only without the poly break. THey used the same wing on the Spectra as well. If that wing can handle all the weight of the stock motor system on the Spectra it will handle ballast with no problem. I picked up a Spectra with an extra wing kit at a swap meet and have built the Spectra (stock) and am building up the second wing now. I've removed the poly break, added a sub-spar, then added full house controls to it. (ailerons, flaps and spoilers) I'm going to make up a pod and boom fuselage to go with this wing and will be building it stout. The wing will also be able to be used on the Spectra, so that would turn it into an electrified Elite.
Old 04-23-2009, 08:32 AM
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Default RE: windy day sailplane

I have the Cularis and it loves the wind. Have a 300watt power system on it. PJS1000, 12x6 folder, 3c 2100lipo.
I have had mine in 50+mph winds more than a few times and it takes it. Wings do bow some.
Using the eagle tree seagull system recorded 74+mph on the high speed dive passes with no wind.
It likes to fly at ~22-24mph in calm to some wind conditions, faster in higher speed winds.
Make sure you have a crow setup to land it unless you have a long strip to land.
The only thing I do not care for is when flying very slow and making a tight turn it tip stalls majorly.
Needs both rudder and ailerons then.
37 minutes has been my best thermal and it was a good one over 1800+, could not do anything wrong that day.
Old 04-23-2009, 10:10 PM
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ORIGINAL: Mtntop

BMathews, I'm mostly a sloper now days but OMG! Just reading that litlle right uup of yours and picturing it with all the gloomy clouds and windgusts......My hearts pounding!

Yep, in both cases the days started out looking fair but by the time I got around to those flights it had turned dark, grey, stormy and all in all rather "biblical".... Definetly conditions that if I had not been out and ready to go already I'd have just rolled over and gone back to sleep or poured a third cup of coffee and gone to the shop.

Who'd have known that actually flying in such "soup" would have proven to been so memorable, if risky.
Old 04-24-2009, 09:55 AM
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Default RE: windy day sailplane

I have only two small slopes that are close (under 6 miles) the rest are 20 miles up logging roads and 4X4 trials. But those two close ones only work during storms in the spring and fall. I've been out with my subzero gear on flying in driving sleat and snow. The worst was when I was flying in 50+ winds and suddenly the clouds broke loose with about 2 minutes of hail!!! I was a hurting unit that day. I actually ended upt with a couple of cracks and dents in my Vmax on that occasion.
Old 04-24-2009, 10:07 AM
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Default RE: windy day sailplane

You went to fly a glider in the 50mph winds with hail on a motorcycle? Or is the Vmax a glider?
Old 04-24-2009, 10:37 AM
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Default RE: windy day sailplane

ORIGINAL: sportrider_fz6

sounds like it could be a fun challenge I'll have to give it a try. I have no glider experiance (unless you count an occational dead stick landing) I was thinking something like this [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXNH96&P=0]spirit elite[/link]

I fly pure gliders most of hte time, mostly 3M + in size. I fly TD most of the time, though I do occasionally fly slope.

1) How do you plan to fly? Are you flying electric or pure gliders? Are you slope
soaring or are you thermal soaring?

2) Are you planning to stay up-wind or will you be flying down-wind?

3) How well do you know how to use your mixes?

4) Do you know how to use ballast?


About Planes

A slow stick is clearly a calm air plane, but I have seen them flown in 15 mph winds.

Many people will say that the Easy Glider is best in lighter winds, and that is true. But I have flown mine in 15 mph winds with no hesitation and thermaled it at that wind speed.

The Spirit Elite, memtioned above, is a good choice for windy conditions since it has a little higher wing loading and the wing is reasonably strong. I would definately want to set up a ballast system so that the plane can be ballasted for windy conditions if you find the need. I would want to be able to add at least 4-8 ounces of ballast and more is not out of the question.

What about 25 mph winds?

Well, what kind of flying are you doing? How likely are you to go thermal
hunting in 25 mph winds? Me? Not likely. Not because the plane can't handle
it but because trying to find and hold a thermal in 25 mph winds may be a
fun challenge, but the thermals will likely move across the field so fast
that you won't be able to stay in them long.

Now, if we are going slope soaring, then 25 mph is fantastic. I might want to add some
ballast to get up some more speed for aerobatics.

None of this has anything to do with a motor. Gliders are all about flying without the motor. However if you have a motor, an e-glider, you have a safety net that can help you get back from a down wind position so you might feel safe to fly in higher winds and hold thermals longer going down wind.

The general rule that bigger flies better applies even more when we are talking about windy conditions. Thinks small boat and big boat in a choppy sea. Nuff said about wing span.

For windy day TD I tend to prefer flatter wing aileron planes in the wind. I have flown my RES AVA in 15 mph winds with 12 ounces of ballast and it does pretty well. But I prefer my Supra and I switch from the 5 degree wing joiners to 2.5 degrees or zero degrees. Ailerons give me more direct roll control but the plane will be less self leveling. Your mileage will vary.

So, how much wind and which glider? That depends on the skills and knowledge of the pilot. In the hands of a talented pilot, quite a bit.

Not sure if that helped.
Old 04-25-2009, 01:49 AM
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Default RE: windy day sailplane


ORIGINAL: Mtntop

I have only two small slopes that are close (under 6 miles) the rest are 20 miles up logging roads and 4X4 trials. But those two close ones only work during storms in the spring and fall. I've been out with my subzero gear on flying in driving sleat and snow. The worst was when I was flying in 50+ winds and suddenly the clouds broke loose with about 2 minutes of hail!!! I was a hurting unit that day. I actually ended upt with a couple of cracks and dents in my Vmax on that occasion.
You win. Even I have my limits and those conditions go far beyond them....
Old 04-25-2009, 10:28 PM
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Default RE: windy day sailplane

Here is a pic of one. It was designed and kitted by Ken Stuhr in the 80's and 90's from VS Sailplanes. It was a pitcheron ship, 17to 1 AR, 78"ws with a seamless kevlar fishnet weave full length on the inner layer of the glass fuse. Mine is awaiting time to be rebuilt.
Though the other would be just as fun too!....Just not in the hail!!
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