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Old Apr 26, 2012, 12:22 PM
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Sweden, Stockholm County, Sollentuna
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How to make controlled landings with a RET-glider?

Hi

I recently got a Fling 2M from Great Planes and I just love it. There is just one drawback - the glide is so much better than my previous glider that I have trouble to land on the short cut grass, let alone at my intended spot.

Could you please share your experience in how to increase precision in landing with a RET.

Thanks in advance for any advice

/Stefan
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Old Apr 26, 2012, 12:49 PM
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Stefan:

I am currently flying a Rudder/Elevator DLG with a rather high performance wing, so I know the problem.

Basic Approach Tip #1: fly S-turns as you approach the field.
Basic Approach Tip #2: fly slower on short final.
Basic Approach Tip #3: practice - a lot!

Good luck!

Yours, Greg
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Old Apr 26, 2012, 01:09 PM
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Do you use a brake on the ESC to stop the propeller? You might try programming a switch to increase the throttle enough to disable the brake (or move the throttle stick up a few clicks), so the prop windmills. Not enough to really apply power, just so the prop will turn in the slipstream. You'll probably find that adds enough drag to make a steeper approach.
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Old Apr 26, 2012, 01:15 PM
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I have an Ascent and a very small landing zone,
At about 20' altitude, and always the same distance from me,I begin about a 50' circle (left or right, whichever suits me at the time)
and maintain that diameter and speed until about 5' high then I bring the nose up gently (still turning) to bleed off speed. By the time i've made a couple more turns i'm slow and low enough to land.
I begin this at cruise speed and use up trim to slow down.
Mike.
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Old Apr 27, 2012, 09:24 PM
MrE
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Add spoilers
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Old Apr 27, 2012, 11:00 PM
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Use a flat approach and carry the speed you need to be sure you get home then touch ground and slide, letting the ground scrub off the speed.
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Old Apr 28, 2012, 05:00 AM
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Thank you all for your advices.



Quote:
Originally Posted by glidermang View Post
Stefan:
Basic Approach Tip #1: fly S-turns as you approach the field.
Basic Approach Tip #2: fly slower on short final.
Basic Approach Tip #3: practice - a lot!
Good tips. How large do you make your S-turns? Are the intention to increase the flightpath or to bleed height through hard banking?

Quote:
Originally Posted by Wazmo View Post
Do you use a brake on the ESC to stop the propeller? You might try programming a switch to increase the throttle enough to disable the brake (or move the throttle stick up a few clicks), so the prop windmills. Not enough to really apply power, just so the prop will turn in the slipstream. You'll probably find that adds enough drag to make a steeper approach.
Thanks. That might make it simpler to hit the runway. I see now that I forgot to mention that I want to learn precision landings to be able to participate in postal thermal duration competitions, and then I think this approach will be illegal? Good for my everyday sport-flying though.

Quote:
Originally Posted by skorski View Post
I have an Ascent and a very small landing zone,
At about 20' altitude, and always the same distance from me,I begin about a 50' circle (left or right, whichever suits me at the time)
and maintain that diameter and speed until about 5' high then I bring the nose up gently (still turning) to bleed off speed. By the time i've made a couple more turns i'm slow and low enough to land.
I begin this at cruise speed and use up trim to slow down.
Mike.
Yes, this has been my primary strategy, but far from as structured as yours. I will try your method next time.


Quote:
Originally Posted by MrE View Post
Add spoilers
Yes, I probably will. But I just bought her and I don't dare to start cut in that nicely covered wing yet. I hope to get courage enough to do it next winter.


Quote:
Originally Posted by aeajr View Post
Use a flat approach and carry the speed you need to be sure you get home then touch ground and slide, letting the ground scrub off the speed.
Yes, this seems to be a good idea for sportflying. As I said a couple of lines above, I forgot to mention I want to learn precision landings - could this method be applied then? In my attempts so far I get very different lengths of the slide, so I don't get much precision (even after touchdown).
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Old Apr 28, 2012, 12:58 PM
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Really, practice is all that is required. It doesn't really matter what you're flying, with enough practice you should be able to land the plane at your feet whether you have spoilers, flaps or just rudder and elevator.

I can land a Gentle Lady, Icon or Habu EDF power-off at my feet ... it's all so much energy management. Once you have flown a plane a number of times, you should have a pretty good idea how to fly an approach to put the model where you want it.
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Old Apr 28, 2012, 01:54 PM
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Practice...practice...practice. In a variety of conditions.
It is energy management. Even flying airplane with "crutches" like spoilers and flaps. I'm regularly flying an AvA. My first spoiler equipped sailplane. It is a landing machine and I only use the spoiler on landing when I screw-up the energy management.

If you have a computer TX, setup a mix or flight mode that will add about two/three clicks of down trim that you can activate as a landing mode. It will help with keeping the nose down and the energy up. "Ballooning" and losing all your energy/speed when turning on final are where most R/E sailplanes miss the landing.
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Old Apr 28, 2012, 05:21 PM
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Actually, on a RE only aircraft, I do just the opposite from Tim, I use AOA (Angle of Attack) to create drag. On the downwind part of the pattern, I want to slow up the ship and get it dragy with positive AOA, and that is the prototypical airliner approach attitude. With practice you can do it and you will find a sweet spot that you can control but it will eat up some altitude for you and be slow enough for time to think. Even on my full house ships, when flaps are deployed, I do not bury the nose with down trim, I will let it rise a bit and start to use up more energy if i am in the wrong side of the approach cone, the high side.

Marc
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Old Apr 29, 2012, 02:34 AM
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In Thornberg's book ( http://carstensbookstore.com/oldbusobobyd.html) he refers to a "magic window". An area you need to fly throught to land where you want.
Found by imagining and LOTS of practice. We all have done this in training where you setup your landing.
Try your appraoaches using little or no elevator to extend the flight or wiggle the rudder to decrease the glide as mentioned before.
I am gonna try the windmilling the prop though :-) Sounds like a good trick
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Old May 09, 2012, 03:22 PM
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I have/had the same problem as my gliders got better at gliding.. My answer is to start my final further out... Nothing helps dump excess altitude like a good tight turn...Just be real sure that you have the airspeed to complete the turn w/o stalling (keep the nose down)..

Don't know about you, but one of the things I really enjoy is watching a sailplane fly forever in ground effect...Adding a little side slip in a crosswind just sweetens the deal
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Old May 09, 2012, 06:13 PM
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OVSS post #10 is pretty much how I do it with my Radian ie AOA. For me if I'm high in the pattern I will fly a larger pattern to loose a bit of altitude or if I'm a bit low I will fly a closer pattern and once I have made my turn to final at an altitude I know I can reach the landing zone I start to increase or decrease the AOA to adjust my decent rate and speed. On breezy days you will want to stay fairly close in and maybe a bit high on final as the headwind and any increased AOA will get the sink rate way up there and your forward speed (ground speed) will become almost 0 ie you may not reach the landing zone. On most occasions with this technique I can land the plane fairly close to my feet or where I am standing or just catch it in my hand, but it does take practice. And it is also a great teaching tool as to how AOA (drag) changes the glide performace of a sailplane.
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Old May 11, 2012, 07:25 AM
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SBS_Pilot:

I hadn't paid attention, so neglected to answer your last question.

For S-turns, the intent is to (as you suggested) increase the flight path. Gentle turns to avoid stalling. This technique also applies to full-scale flying, and is what I used to use when landing out in sailplanes (even sailplanes with effective spoilers).

Something else I neglected to include, but should have: it helps a lot to have a landing pattern, just like full-scale. Flying downwind, base leg and final approach gives the pilot (on-board or RC) a full spectrum of clues about the landing approach and where the airplane ought to be.

Ironically, once you make a landing pattern both practice and habit, it becomes much easier to employ variations with safety.

Yours, Greg
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Old May 11, 2012, 08:11 AM
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