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Old Jun 12, 2014, 03:51 PM
"Get off the runway!"
Da Big_G's Avatar
United States, TX, Hutto
Joined May 2012
530 Posts
My new radio has a mix called "air brake" which proportionally uses up ailerons (spoilerons) slaved to down elevator and that mixed to throttle. I have not tried it, but any mix of control surfaces "should" slow the landing speeds down...kind of the way cross coupling ailerons and rudder work. Some F3A pilots say free-wheeling prop slows off throttle down lines better than esc braking. It's also much less energy consumed by the esc..(runs cooler).
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Old Jun 12, 2014, 04:24 PM
Registered User
Sverige, Värmlands Län, Filipstad
Joined Jan 2009
1,139 Posts
Or use electric brakes on the main wheels like Hanno Pretttner did on his Curare.
He used Graupner nr 142 electromagnetic brakes, see picture below of his Curare from 1977.

/Bo
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Old Jun 12, 2014, 05:04 PM
WBE
Las Vegas Circle Burners
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United States, NV, Henderson
Joined Aug 2005
587 Posts
Doug, if you drive each aileron with a dedicated servo they can be programmed to operate as flaps during your approach. I've done this to good effect on RC planes before. Typically you'll also need to program a little down elevator to counter the nose-up pitching moment. I used a toggle to switch to a "landing flight mode" rather than having the flaperons auto activate at low throttle because I didn't want that function to kick in during stall/spin maneuvers.

Bill
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Old Jun 12, 2014, 05:49 PM
Raised on 80's Pattern
Fatherof4's Avatar
Rancho Santa Margarita, CA
Joined May 2006
1,299 Posts
Quote:
Originally Posted by bossee View Post
Or use electric brakes on the main wheels like Hanno Pretttner did on his Curare.
He used Graupner nr 142 electromagnetic brakes, see picture below of his Curare from 1977.

/Bo
Although slowing down once on the ground is challenging, (ask Robert about that!) my goal is to slow the plane down in the air to increase the sink rate and land at a more reasonable speed. The issue is that the plane does not bleed off airspeed like a typical Classic. Therefore is just sails past you on landing unless you start your approach VERY low.

If I am able to slow the airspeed, brakes will not be necessary.

Thanks and keep the ideas coming.

Doug
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Old Jun 12, 2014, 06:30 PM
Registered User
Joined Apr 2011
55 Posts
I would go with the esc brake, and add air brakes to the main gear legs. By having the brake activated the prop will require more energy from the freestream to turn the motor so you'll get some more drag there. The strut mounted airbrakes will give you more drag as well.

I'm not sure if dailing in flaperons is the way to go as you'll end up changing pitch moments and reduce your roll authority. One thing you could try is a slight change to your approach. Have you tried slowing the airplane further on downwind and then flying the approach at a higher angle of attack such as a jet would?
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Old Jun 12, 2014, 09:50 PM
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SoCal
Joined Feb 2004
385 Posts
Add the speed brakes. They really work well.
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Old Jun 13, 2014, 09:51 AM
West Coast Director, CPA
Vertigo II's Avatar
Simi Valley, California
Joined Jan 2010
720 Posts
Doug,
Yours is a two prong problem:
1. Lack of aero drag.
2. High mass (momentum) to decelerate once on the ground.

For part 1, the ESC braking and drag brake doors are the most practical approach.

For part 2, I suggest trying the Du-Bro brake on the nose wheel.

http://shop.dubro.com/p/e-z-brake-system

I would shy away from the tightening the wheel collar approach as it is very difficult to control the amount of friction, and the result is a pull to one side or another. The brake gives you control and does not affect takeoff. You can set up the brake with a small servo on a separate channel, or tie it to down elevator. I have used the down elevator approach in the past and the down elevator has the added advantage of pushing the nose wheel down for more traction. Simple and light.

Anything to prevent those embarrassing overruns!!
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Old Jun 13, 2014, 12:06 PM
AMA MEMBER
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United States, CA, Redondo Beach
Joined Mar 2010
384 Posts
Hey Robert

That's what I needed that day I went off the end of the run way at Sepulveda Basin! ha ha ha
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Old Jun 13, 2014, 12:27 PM
CPA #100
flyonenow's Avatar
United States, CA, Perris
Joined Nov 2008
117 Posts
+1 on Roberts 2 cents.

The only issue I see with the Dubro brake set up is the size of wheels listed as compatable being 2.25 to 3.5" I'm sure this is due to the way the unit locks into the hub. To solve the large wheel thing you could try swapping hubs?

Hmm. I wonder if Kevin would be ok with adding drag brake doors?

Paul
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Old Jun 13, 2014, 12:31 PM
West Coast Director, CPA
Vertigo II's Avatar
Simi Valley, California
Joined Jan 2010
720 Posts
Or maybe this.............
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Old Jun 13, 2014, 02:00 PM
CPA #100
flyonenow's Avatar
United States, CA, Perris
Joined Nov 2008
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LOL! That'd work.

Paul
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Old Jun 13, 2014, 05:14 PM
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United States, CA, Redondo Beach
Joined Mar 2010
384 Posts
You could use the 2.25 wheel and put it in a drill, drill press, or lath and spin it down some with sand paper on a block to 2" or smaller. Just a thought.
Now those would be some low bounce tires.
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Old Jun 13, 2014, 06:22 PM
AKA 8178
Jet_Flyer's Avatar
Joined May 2004
1,131 Posts
One of the challenges I find with classics running big props like a 12-10W is getting the engine to idle down slow so there is very little thrust when you are on final. Then it is a simple matter of slowing the airframe airspeed with a nose high attitude. Once you get on the glide slope in that mode you control the speed of descent by adding or reducing power.

Because sparkies can have zero thrust it should be super easy with them.

Mike
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