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Old Nov 22, 2012, 08:28 PM
Tragic case
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Finding thermals is like anything else partly theory and partly practice. The suggestion I have for anyone that is interested enough to put some real time in, is to go off to a local competition.

The benefits of this are many.
1. You get to fly at different fields, this is helfpul to understand what stays the same and what differs between fields.

2. You get to fly with and against other flyers. It may seem surprising to a newbie but its much easier to find thermals at a competition than anywhere else because the other pilots do the work for you.

3. You get to work on specific tasks, like how to manage your plane when its in a thermal, how to land on the spot, how to mange energy and time.

4. You will usually meet a nice bunch of people who will reinforce the values you get from the hobby.
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Old Nov 22, 2012, 09:42 PM
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Thanks

Great thread!
Thanks everyone for sharing this good stuff.
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Old Nov 23, 2012, 02:15 PM
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You're welcome, Tom. Feel free to ask about anything we've said or anything we've missed. Someone is bound to come up with an opinion.

That is an awesome idea, David.
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Old Dec 03, 2012, 04:49 AM
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Just want to know if anyone uses a standard prop if a folding prop isn't availible. apart from maybe catching on the ground when landing. Does it make a difference when just sunday flying?. cheers.
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Old Dec 03, 2012, 08:52 AM
WAA-08 THANK FRANK!
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The drag caused by the spinning prop will be like having an anchor attached. Avoiding having that drag is the whole purpose for the folding prop in the first place. If you want to glide and catch thermals, you need a folding prop and a brake function on the esc. The brake stops the prop, kills the centripital force that keeps the prop extended and the drag on the blades causes them to fold back against the fuse into a very low draw profile.
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Old Dec 03, 2012, 06:38 PM
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Hi, guys.

I've been pressed for free time but I have spent some idle moments deciding which tips should be included in a sticky post. Here's where I'm at so far. Please let me know what should be added or removed.

1, the single best bit of advice we can offer! Find an experienced sailplane pilot to help you out. Everything else we can offer pales in comparison.

The rest is in no particular order.

2. Attend and/or enroll in contests. This is actually an addendum to number 1.
3. Start with a sailplane that has a good reputation and then fly the heck out of it. Most sailplanes are better at soaring than we are and there are no magic bullets.
4. Keep things simple. A high performance sailplane with all kinds of control surfaces and mixing thereof just makes the initial learning curve a bit more steep. Start with a sailplane that, mostly, flies itself so you can concentrate on utilizing lift once you find it.
5. Watch the birds! Birds are better at soaring than we can ever hope to be. If you see a hawk, vulture, eagle, or seagull rising in a thermal? Go chase it!
6. Use your senses. Try to attune yourself to subtle shifts in wind to find thermals.
7. Seek out areas where there is a temperature differential. Places like big chunks of asphalt and plowed fields can create a local temperature differential and it's that differential that creates thermals.
8. Learn to fly your sailplane by following a plan. Even if you have not found any lift set out to make circles where you want them. Make figure 8s where you want them. Make S-turns where you want them. Make landings where you want them! Fly when there's some wind and learn to deal with it.
9. Do some aerobatics. If you learn to recover from situations where you went out of control on purpose it will help you if you go out of control by accident.
10. Study. There are many books, videos, and articles that have lots of good information. Some have been mentioned here and there are many more.
11. Ask questions. Whether it's here, at the local flying field, or some other forum you will find that there are a lot of people who want to help you be the best pilot you can be.

That's where I'm at for now. It's not meant to be a complete list yet but I will need more input to get said complete list.

Cheers!
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Old Jan 04, 2013, 06:23 PM
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Hi, guys.

It's been a rather hectic month so I haven't been able to work on the thread but i have kept it in my thoughts. Giving some thought to flying scale gliders, as opposed to purpose-designed floaters, I realized that we haven't really covered the different approaches needed for different styles of sailplane.

The biggest thing, when flying a relatively heavy scale glider, is to keep your speed up and that means that, unless one is working very large and strong thermals, it's best to not even try to stay inside the core of a thermal. I've attached a very crude drawing of my method. The orange circle is the thermal and the black oval is the flight path. You can pull the nose up, within reason, to tighten the turn inside the thermal but then one lets the nose drop to pick up airspeed while outside the thermal. It's a bit counter intuitive but it works. In fact, when the lift is really light and the thermals are small, I don't even try to turn while in said thermals. I just pull the nose up to gain the maximum amount of lift and then move on to the next or make a wide, flat, turn to bring me back.

This technique is meant to take advantage of the relatively high lift to drag ratio with a typical scale glider's high aspect ratio and wing loading. It also works whenever the thermals are so small that one stalls out trying to make a tight turn inside said thermals. It also brings up, in very general terms, another rule of thumb.

If you are in sink? Let the nose drop to pick up speed in order to reach the next bit of lift. If you are in lift? Slow down to get all the altitude said lift has to offer. A very common mistake among beginners and experienced pilots alike is the urge to always maintain the minimum sink rate even if one's airspeed drops to the point where one isn't reaching the next bit of lift. Again; fly slow in lift and fly fast in sink.

PS. If someone who is not artistically challenged could come up with a better drawing I would be most grateful.
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Old Apr 16, 2013, 04:00 PM
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Quote:
Originally Posted by peterlngh View Post
Here's another one I forgot.

Almost all motorized gliders will want to pitch the nose up with the motor on. The faster you go? The more it wants to climb. It just becomes second nature to push the nose down but there is another way. Just climb in a spiral. Adding some bank reduces the tendency to pitch up.

Keep the ideas and questions coming!
The more I push the throttle up on my Calypso, she just flew level at the best. So, are you suggesting I should adjust CG from 1/4" ahead of spar to at least on the spar?

http://www.rcgroups.com/forums/showp...&postcount=620
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Old Apr 16, 2013, 05:19 PM
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I will give a qualified "yes" to moving the CG back a bit. Placing it on the spar with the necessary change of the tail incidence should get you started. The Calypso, in my limited experience, should climb like mad when you hit the throttle.

Cheers!
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Old Apr 16, 2013, 09:52 PM
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Really?

Almost all motorized gliders will want to pitch the nose up with the motor on. The faster you go? The more it wants to climb. It just becomes second nature to push the nose down but there is another way. Just climb in a spiral. Adding some bank reduces the tendency to pitch up.


Okay if you are truly interested in teaching something about sailplanes, then lets engage those little grey cells a bit before pushing the same old mis-information. "IF"

It is the tail that directs the nose...turning the motor on can't cause an airplane to "nose up", it can only make the model go faster. It is not a directional device.

But Peter you are right in your statement that "almost all motorized gliders will want to pitch the nose up with the motor on".

I know first I said it can't happen now I'm saying you are right about "almost all motorized gliders".

The tail directs the nose. Airspeed empowers tail feathers and "most motorized gliders" have been set up crooked....with up incidence in the stab. Turn the motor on - airspeed increases - and the crooked tail gains strength causing the nose to "pitch" upwards....the tail, not the motor or the wing.

This pitch up problem lead to a guy figuring out that if he mounted the motor firewall crooked (down thrust) he could stop pitching upward when motor was engaged. Finding that idea worked out, he then wrote an article crowing about how since "most motorized gliders will pitch up with the motor on, its only logical to mount the motor crooked".

Not one of you heard that and said, "Hold on a minute! You're saying that you want me to mount the motor crooked, so that the thrust is not in line with the wing's chordline? That sounds pretty inefficient!"

The next fix was easier and that came about when some 'motorized gliders' came with a full flying stablizer. Incidence could now be straightened with the elevator trim tab! But since "most motorized glider flyers" were flying so nose heavy, they found that with if there wasn't up incidence in the full flying stab, the model wouldn't fly level...so they poured in the up trim, making the model crooked again....Yipes they said....Now the model pitches up when ever the motor is turned on again!

"No worries!" said the down thrust guy. "Our new radios allow us to program in down incidence (down trim) as the throttle is applied...we are saved!...as he walked away grumbling about why the heck the designer didn't put down thrust into the firewall?..."

If you have one dot more lead in the nose of a sailplane than is needed to make it fly forward, then it will fly forward and nose down...to fix that you'll need to program in some up trim....and then when you turn on the motor the model will pitch up as it gains speed, then you can program in some down elevator compensation tied to the motor stick .... all is good in the world!

Or you could get the model balanced so that no up trim is needed, and mount the motor straight with the wings chord line, then when you turn on the motor the model will go up....No it won't "pitch up" the nose with the added airspeed - instead the added airspeed will cause the wing to lift and the model will rise. (The wing lifts the model...not the nose).

I have provided a clear explanation of what causes what. Can you ? :-)

And by the way...unless I am mistaken a Calypso is a rubber airplane. IF rubber airplanes didn't flex and twist as airspeed increases, they would be used in F3J, F3F, F3B, F3K, and full size aircraft. Please enjoy the Calypso, don't expect it to be carbon. It wil NEVER fly the same twice...but it will likely always be fun to fly.
Gordy
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Old Apr 16, 2013, 11:04 PM
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I'm simply not interested in a pissing contest, Gordy. A high lift airfoil, regardless of tail airfoil or incidence, will tend to climb with increased speed. That's a simple fact. There are lots of reasons for that but that delves into a realm that goes beyond the "entry level". The point that I try to hammer home is that it's best to trim a sailplane for the glide and compensate while under power.

Most of us will never fly a rigid, composite, contest-grade glider and that's not what I'm trying to address with this thread. This thread is meant to help the Sunday flier with a "rubber airplane" like the Calypso.
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Old Apr 17, 2013, 05:29 AM
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I'm a simple carpenter, but I am also a contest pilot.

I prefer to know the reasons why, and I like the way Gordy puts it in simple terms that I can understand.
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Old Apr 17, 2013, 11:35 AM
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Thanks Gordy and your statement "The tail directs the nose" make me wondering how to check tail incidence? I was pretty sure when I did maiden and crash Calypso, there was no "nose pitch up" at all under power. Considering my CG still within recommended forward limit, is that mean something wrong with tail incidence?

Peter, I see your comment on "change the tail incidence", how can I do this?
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Old Apr 17, 2013, 12:44 PM
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Well, Kenny, my issue with Gordy is over style not substance. It began with his assertion that flying an electric sailplane with the throttle on the left stick is "moronic" and "dangerous" despite the fact that some of us still use our old 4 channel radios that have no other option. Personally, I like to keep throttle on the left stick because that's how I learned and I switch back and forth between gliders and powered planes. The fact of the matter is that there are many ways to do most of the things we do. That's why the thread is called "soaring hints" rather than soaring rules. I welcome the knowledge and expertise of everyone but there's no reason to be confrontational or contemptuous of others.
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Old Apr 17, 2013, 01:20 PM
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If you look at this pic, GTstrudl, you will note the "notch" that the tail fits into. One then makes a shim to fit said notch that will raise the rear of the horizontal stab. Most guys seem to have settled on about 1/8 inch. The material used doesn't much matter as long as it won't compress.

http://static.rcgroups.net/forums/at...g?d=1340539927
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