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Old Dec 27, 2013, 11:37 AM
Dean
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Seeing how quickly that MKS flap servo gets hot when I plug it in now tells me the traces in the receiver can take much more current than I thought!
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Old Dec 27, 2013, 05:12 PM
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If the flaps deploy ~70 deg just put them out before the dive and then go staight down, Model shouldn't pick up much speed in the dive.

Much safe as deploying flaps on the dive .
@aeajr

100mph is pretty fast for a J ship, don't think a PP (which is a faster J ship) can make it.

Cheers
Thomas
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Old Dec 28, 2013, 09:43 PM
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For electric gliders:

Thinking outside the box....how about adding a little power?

My thought process is as follows. The prop disk will provide more drag than power if enough juice is put through the ESC to prevent the brake from working.

It worked with a full scale Cessna 140. In an experimental glide from 11,500 down to sea level, I found there to be much less drag with the prop stopped as opposed to windmilling (as suspected).

It may be a month or two before I have to chance to test this idea, but somebody with a plane, vario, time and nicer weather than I have might be able to gather some data!

Cheers!

SLCPilot
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Old Dec 28, 2013, 09:50 PM
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SLCPilot

That might work but would be contrary to flying it as a glider.
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Old Dec 28, 2013, 10:18 PM
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But, isn't the theme of the thread saving the aircraft? I'd gladly sacrifice quite a bit to use ALL tools available to to save the aircraft.

Cheers!

SLCPilot
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Old Dec 28, 2013, 10:32 PM
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But, isn't the theme of the thread saving the aircraft? I'd gladly sacrifice quite a bit to use ALL tools available to to save the aircraft.

Cheers!

SLCPilot
Well, any aspect of flying has the theme of saving the aircraft. And if you have this option well, you would be foolish to ignore it. Heck, if you are just going to turn on the motor then none of this discussion is really relevant. Just power up, fly out of the thermal and be done with it.

But if you are flying a pure glider you take that option away. And since this is in the XC forum and there are few XC electrics the real discussion is how to get down safely as a glider, not as a powered aircraft.

So this discussion is about how does a GLIDER/SAILPLANE pilot do this, not how does a power pilot do this.
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Old Dec 29, 2013, 04:47 AM
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The free filght rubber flyers found out decades ago that windmilling props have more drag than a stopped prop.

back to the topic, considering the purpose different purpose of flaps and spoilers. namely flaps increase drag, spoilers spoil lift. When you are high up and need to destroy lift perhaps one answer is to apply up aileron only, but lots of it 70 to 90 degrees (much like traditional spoilers)It worked well on a 4m soarer I used to fly and by mixing in up elevator I could control any speed build up very well.
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Old Dec 29, 2013, 07:10 PM
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Originally Posted by mhodgson View Post
. When you are high up and need to destroy lift perhaps one answer is to apply up aileron only, but lots of it 70 to 90 degrees (much like traditional spoilers)It worked well on a 4m soarer I used to fly and by mixing in up elevator I could control any speed build up very well.
Bad idea IMO, ailerons up don't slow down much and load the wing with negative g's which is really bad.
But not all 4m soarers are equal, there are Gasbags/ floaters and are more scale likes ( like for cross country were you need some legs)


Thomas
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Old Dec 30, 2013, 04:00 AM
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Point taken.
However, I found that using the elevator prevented any speed build up. The wing acted a bit like a large air brake I reckon.
Also most wings are built as strong in the negative as the posite g. Also you would offloading the positive g already on the wing. It is all about preventing too much speed build
up. And have you seen the frontal area ailerons add when raised to 70 degrees or more?
It worked well on my 4m and that was hardly a floater with a10oz+ wing loading. It's worth a try if you already have ailerons.
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Old Jan 02, 2014, 08:04 PM
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I tend to trim my gasbags so that their speed is sort of proportional to the elevator trim which is mixed to the throttle stick. No real guessing how fast the thing is flying , the throttle stick position is a good indicator.

In the past I've seen guys blow up ther gasbags because they can't hold in just the right amount of down elevator to maintain a constant speed and start zooming up and down, with the wing either fluttering off from too much speed, or breaking off when they panic, pull up too quickly trying to wash the excessive speed off.

Step one is to push in that bit of down to increase the speed and sink rate and hopefully find some sink, step two is to slow down and pop the spoilers (sinks at a leisurely 20ft/sec with full spoiler) and if it doesn't start getting smaller with that I start poking in a bit of down elevator knowing it can't get away with the spoilers out.

Spending a few minutes setting up a condition or mix in your radio where your glider can loose height quickly with very little pilot input is time well spent.
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Old Jan 02, 2014, 10:07 PM
Dean
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You mean start getting larger?
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Old Jan 03, 2014, 06:36 AM
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You mean start getting larger?
Yep, if it doesn't start getting larger.... First stuff up for 2014
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Old Jan 03, 2014, 09:01 AM
Dean
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K Mate, the rest of the year will be great!!
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Old Jan 03, 2014, 03:16 PM
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I have never been in lift so strong that I was worried about getting down. But I have been in contest situations where I stayed too high for too long and had to race to get down for the timed landing.

On my Radian it is the up elevator/hard right or left rudder. Basically stick in left or right bottom corner. Works great!

On my full house planes I just deploy flaps and point the nose down about about 60 degrees and down she comes.

In both situations, I leave the lift first.

Never been in lift where these would not work.
Quote:
Originally Posted by aeajr View Post
Well, any aspect of flying has the theme of saving the aircraft. And if you have this option well, you would be foolish to ignore it. Heck, if you are just going to turn on the motor then none of this discussion is really relevant. Just power up, fly out of the thermal and be done with it.

But if you are flying a pure glider you take that option away. And since this is in the XC forum and there are few XC electrics the real discussion is how to get down safely as a glider, not as a powered aircraft.

So this discussion is about how does a GLIDER/SAILPLANE pilot do this, not how does a power pilot do this.
It's hypocracy I don't like. In your first post you lead off with discussion of your "power" plane, and then you criticize others for discussing the same thing. Maybe it comes with the wisdom of 22,000+ posts.

If you're this kind of an ambassador to the sport of XC flying, it will die soon enough.

I was just trying to contribute ideas to those who fly high and want to save the plane. Me? I just fly a cheap 3.45m Masala, and can't afford the high dollar soarers since other things take my time as well.

Cheers!

SLCPilot
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Old Jan 03, 2014, 04:15 PM
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It's hypocracy I don't like. In your first post you lead off with discussion of your "power" plane, and then you criticize others for discussing the same thing. Maybe it comes with the wisdom of 22,000+ posts.

If you're this kind of an ambassador to the sport of XC flying, it will die soon enough.

I was just trying to contribute ideas to those who fly high and want to save the plane. Me? I just fly a cheap 3.45m Masala, and can't afford the high dollar soarers since other things take my time as well.

Cheers!

SLCPilot
I apologize if I offended you. Not my intent but I have been known to do that from time to time.

I am flattered you called me an ambassador to XC, but would never consider myself as such. I am a glider pilot and I thought we were talking about flying gliders.

The "plane" I talk about in the first post is a glider. Gliders are airplanes that are flown without the benefit of a motor to keep them aloft. So I sometimes switch between plane and glider and sailplane. I do own a few small electric airplanes but none of the ones I own have flaps. And I don't thermal soar them, which is why I don't fly them very often anymore.

Along with my pure gliders I also fly e-gliders. On my e-gliders the only time the motor is used under normal conditions is for climb out. As a last resort, if I were out too far and too low and would end up in the trees or other bad places, I abandon the idea of flying it as a glider and turn it into a power plane by turning on the motor.

Your contribution was about using the motor as a brake to get out of lift. Nothing wrong with that. That is fine if you want to fly your e-glider as a powered airplane. Nothing wrong with that at all and certainly a much better idea than losing the glider.

I took this discussion to be about how one gets a glider down from strong lift using glider approaches and capabilities. If that was not the case I beg forgiveness of all who posted.
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