D_Thissen Show full post »
sunnyboy44
Backtrack a bit..

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Right now I'm only using THREE of them. But I'm confused enough already, don't add another thing for me to try and learn about....airbrakes?

David


I want to try to help clear up one of your confusions. Yesterday I was also puzzled by how flaps work, but then I read, and watched, through this thread by Dred:

http://www.rcpowers.com/forum/showthread.php?t=89&page=4

Be sure to watch the video called "YouTube - King Schools Video: Taming Stalls & Spins" it's all about how flaps work.
Hope it helps,

-Caspar
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eljay
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I want to try to help clear up one of your confusions. Yesterday I was also puzzled by how flaps work, but then I read, and watched, through this thread by Dred:

http://www.rcpowers.com/forum/showthread.php?t=89&page=4

Be sure to watch the video called "YouTube - King Schools Video: Taming Stalls & Spins" it's all about how flaps work.
Hope it helps,

-Caspar

Thanks! Very Much!

David
If there are no dogs in Heaven, then when I die I want to go where they went. - Will Rogers
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PecanGrower
The King videos are awesome.

Keep in mind that with flaperons, your ailerons and flaps are on the same segement of the wing. With flaps down, this is the part of the wing that will stall first, so your ailerons become ineffective first.

If you feel like you understand angle of attck, here's another way of thinking about flaps. Flaps cause the angle of attack to increase for the wing segment they are attached to. In the video, they are on the wing root. The wing root now has a higher angle of attack than the wing tip, so the wing root stalls first.

Stalls are caused by an angle of attack that is too high. Typical stall angles are between 8 and 20 degrees.

LowKey asked about spoilerons. Well, imagine them being the reverse of flaps. Spoilerons decrease the angle of attack for the segment of wing they are attached to. Since the ailerons share this wing segment, the ailerons are on the last segment to stall. This is why Dave uses spoilerons for high alpha. The wing segment with the ailerons is still flying and therefore still controllable. The other segments of the wing will stall, but this loss of lift is compensated by additional thrust.

LowKey: The short answer is: Spoilerons do not make your plane fly slower. Simply adding spoilerons will not magically slow down your airplane.

The long answer: Spoilerons will enable you to fly at a much higher angle of attack. Higher angles of attack are inherently slower than lower angles of attack. Think of the pitch of the airplane controlling the speed. The higher the pitch angle, the slower the airspeed. Flying at a higher angle of attack requires additional pilot skills.

To land slower, I recommend learning to trim the elevator for airspeed. This is the best way I know of to accomplish slow, stable flight in an ordinary flight attitude. Once you get the hang of this, adding spoilerons will enable you to increase trim for even slower airspeeds.

Hope that all helps.
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D_Thissen
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Stalls are caused by an angle of attack that is too high. Typical stall angles are between 8 and 20 degrees.


And that doesnt mean 8*-20* above the horizon. You can be heading straight for the ground, and if you pull back too quickly you will stall because the wing exceeds the critical angle of attack (the relation of the wing to the relative air flow). So it is possible for a plane to stall at any speed (does not have to be slow) and at any attitude (do not have to have the the nose straight up)
http://en.wikipedia.org/wiki/Stall_(flight)
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PecanGrower
You're just itching to do an article on stalls, aren't you?
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D_Thissen
i just wrote a few flying exams so i have this info just sitting in my head haha:haha:haha:
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metalfan49
Looks like there's a video for the EZ Hawk now -


Confirms that it is a 3-channel with throttle, aileron, elevator, but no rudder control. I think it uses the same radio equipment though, as it's mentioned that you can just add your own rudder servo if you want one.

Anyone else notice that Nitroplanes seems to do their videos at the same field as Banana Hobby? You can see the 'Do Not Fly Over Rifle Range' wall in both vendor's videos.
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cisc0box
That's because the people at Nitro are related to the people at Banana (from what I've heard) .... they're close by.
My Fleet:
Extreme Lama v3 - Dynam Hawk Sky - Angel-EPP
Techone Angel-EPP Build Thread
"http://www.rcblog.digs.it"
CB-RC Review Community
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pghern
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That's because the people at Nitro are related to the people at Banana (from what I've heard) .... they're close by.


The guys in this video looks like he could be "Peter from BananaHobby.com" bother! Even speaks the same.
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kevrees
Hi, just a quick question. Am looking to be getting an ez hawk in the next week or so, if i can dinf somewhere that has them in the UK, quick google search should hopefully find someone who has it in stock mind.
Anyway, was just wondering if its possible to switch the aileron servo to control the rudder instead. The reason i ask is cos my missus wants to fly it as well. We both have flown the hz champ and want something with a larger wingspan to be able to power up to gain some altitude then switch the power off just to glide around for a bit. Anyway, she doesnt feel too comfortable with trying something with ailerons at the moment, and im not overly confident about it either, although i used to fly epp flying wings about 6 years ago (zagi's mainly) so, without sounding arrogant, would be able to make the switch easier than her so just thought if we could turn the aileron control off and have rudder/elevator control and once we both got the confidence, can add aileron control later on which will also give it more longetivity.
If this is possible and anyone has tried this, please could you let us know how easy it is to do and how you got on.
Cheers
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dtribby
Unplug the AIL servo(s) fom the Rx, plug rudder servo into AIL channel. Verify correct throw direction. Reverse if necessary. Go fly.
Yes, I've known that I'm "different" for some time now...
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4FunRC
Ah, err... flaps actually DO SLOW DOWN an aircraft. They really, really DO.

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Hey eljay.

You've actually got a few items there I should address, but we'll start with the servos. If you mount the servos 'opposite' to each other and use a Y cable, they will move opposite (ie. Like ailerons). If you want them to also be flaps, you remove the Y cable, and plug the 2nd servo into an aux channel. At this point you either need a transmitter that will mix, or an onboard mixer. I don't know the mixing functions of your transmitter, but if you tell us what it is, I'm sure someone here can help.

Flaps: You say your reason for flaps is to 'slow down that fast-gliding plane for landing'. I'm going to attempt to get you thinking a little differently about flaps. Here goes.

1) Flaps do not 'slow down' an airplane. Flaps generally reduce the stall speed speed of an airplane. This slower stall speed enables you to increase both the angle of climb and the angle of decent.

2) Aircraft speed is usually adjusted through a combination of thrust and pitch angle. As you presumably already have the thrust at zero, you decrease the airplanes speed by increasing the pitch angle (nose up).

I don't know your pasture, so flaps may actually be necessary. Let me tell what I do in order to 'slow down' the airplane for landing.

First, I want to be in level flight at minimum power (that's 50% throttle for my Hawk Sky). Next, I want to apply full back elevator trim (don't have any more trim? This is why zeroing out the mechanical trim is so important). Lastly, I want to pull the throttle to zero.

Here's the key, slow flying airplanes need a much smaller turning radius than fast flying airplanes. Your plane should be able to fly slow enough that you can do a circling decent inside your pasture. I haven't tried it with my Hawk Sky, but I'd guess decent radius is under 50ft. How small is your pasture?

If you find the airplane is still too fast with full back elevator trim, try adjusting the the linkage to the point where you can give it full back trim, but the plane won't stall. You can test that at any throttle setting. Speed is speed, so if the trim setting stalls the plane at 50% throttle, it will stall it at 100% or 0% throttle too.

Hope I haven't confused you more.
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