Hi everybody. It's my first post here.

We bought Cessna A185E, year 1970 several months ago from Hungary. It will be the first Skywagon in the Czech Republic.
Although from distance it looks great, once we get closer it has a lot of imperfections, so we just started the complete overhaul.

Question - as you can see the photos, the ailerons are not straight, but the edge is curved. It's going up once further from the fuselage.
I thught originally that it is wrong. So I bought in Aircraftspruce new aileron skin sets and ask mechanic to make "new" aileron.
But my mechanic is not sure whether he should keep it curved like this or whether he should make it straight. When I look at illustrated parts catalogue I see it straight. Can anybody please advise? Thanks.

Mine are curved so that when the aileron and flap trailing edges are lined up, the tip curve up a bit and is lined up with the wing tip. From your picture, it looks like your aileron does the same thing.

The last 8-10 inches start a gradual curve to meet the wingtip when the flap side is aligned, provided your flaps are rigged correctly. Both of my 185's where that way.

A 1979 180K was just shipped the Czech Republic last summer from San Diego CA. It was very original with 720 total hours and just like leaving the factory. I should have bought it. You might see if you can find it as it would be a very good one to look at for what is right and wrong.

A mechanic can get the correct wordage. The wing is washed in or out (twisted) to mitigate adverse yaw. The outboard section, in front of the aileron, has less incidence so it will generally be at less angle of attack than the inboard section. Or is that always less angle of attack? Somebody always nails me on that stuff. Anyway, the wing is twisted a bit. The aileron twists a bit to follow exactly behind it.

A Piper or Maule wing won't mess with your mind like that.

Yep, the ailerons have some washout (trailing edge curves upward) near the wingtips.

contactflying wrote:A mechanic can get the correct wordage. The wing is washed in or out (twisted) to mitigate adverse yaw. The outboard section, in front of the aileron, has less incidence so it will generally be at less angle of attack than the inboard section. Or is that always less angle of attack? Somebody always nails me on that stuff. Anyway, the wing is twisted a bit. The aileron twists a bit to follow exactly behind it.

A Piper or Maule wing won't mess with your mind like that.

I am sure this has nothing to do with adverse yaw. But it has a lot to do with making sure a stall starts at the root and works outward. One of the things that make High wing Cessna have good flying qualities.


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Many thanks to all of you for the answers. I got it it. It's clear now.

A 1979 180K was just shipped the Czech Republic last summer from San Diego CA. It was very original with 720 total hours and just like leaving the factory. I should have bought it. You might see if you can find it as it would be a very good one to look at for what is right and wrong.

You're right. Petr Kopfstein (red bull air race pilot) bought 180. But I have not seen it yet. I thought I was still in US. So in the Czech Republic we do have now 1x C185 and 1x C180 There are also 3x Super Cubs, all registered in 2016.

That Skywgnyqa, and something makes airplanes with washed out wings turn without rudder. Unwashed or unbungeed wings, Ercoupe excepted, will not turn without rudder. Flying the aileron at less angle of attack keeps funky ailerons working at slower speed, where rudder actually works much better, giving the pilot the dangerous impression he should bring the upset or down wing back up with aileron. This when he needs to stand on the opposite rudder to get the down wing up smarty and safely without stalling the down wing.

I know the washed out aileron is supposed to help this situation and it does; so long as somebody teaches the pilot to use lots of rudder to get the wing back up. With modern airplanes Dutch rolls to 45% bank are very helpful getting this point across.

Unless you crop dust, have a serious upset, or need a tight canyon turn, you don't need to use lots of rudder to get the wing back up. If you encounter the need, only rudder will make it a comfortable and safe return to wings level

Not great pictures, because I’m not at work at the moment, but here is a picture of the aileron jig. The jig with the draw Clecos in the end pocket. This jig does left or right. The aileron fits in with the trailing edge up in the air vertically. The view is from the inboard end looking outboard. You can see the curvature of the ailerons at the far end of the tooling. It’s actually quite a bit.


This picture is from the outboard or tip end of the jig looking inboard. All of the Cessna 100 series ailerons fit in the same jig, the primary difference between say a 185 and a other models being the amount of lead used for balance purposes.



While many repairs are successfully made in the field, it’s difficult to duplicate the accuracy of a standard and more often than not, the result is while functional, somewhat less than perfect. Combine this with a wing tip repair resulting from a ground loop that is also not jigged and the airplane flys one wing low, with insufficient travel in the eccentric bushing to correct it. While great for keeping pilot awake on long cross countries, it’s aggravating to put it mildly.

If I remember, maybe the next aileron I reskin , I will post a series of pictures of the process from start to finish.

That's pretty cool. Thanks for sharing the jig pics. Im afraid those things are slowly fading away, tossed, or melted for scrap. Nice to see...

Would love to see a start to finish in the jig!!!!

contactflying wrote:That Skywgnyqa, and something makes airplanes with washed out wings turn without rudder. Unwashed or unbungeed wings, Ercoupe excepted, will not turn without rudder. Flying the aileron at less angle of attack keeps funky ailerons working at slower speed, where rudder actually works much better, giving the pilot the dangerous impression he should bring the upset or down wing back up with aileron. This when he needs to stand on the opposite rudder to get the down wing up smarty and safely without stalling the down wing.

I know the washed out aileron is supposed to help this situation and it does; so long as somebody teaches the pilot to use lots of rudder to get the wing back up. With modern airplanes Dutch rolls to 45% bank are very helpful getting this point across.

Unless you crop dust, have a serious upset, or need a tight canyon turn, you don't need to use lots of rudder to get the wing back up. If you encounter the need, only rudder will make it a comfortable and safe return to wings level

Jim,

I almost started a new thread to hit this but I wanted my response in the same place so that someone searching in the future runs across both posts in the same thread.

You may confusing washout, which is a twist in the wing, reducing the angle of incidence from the root (highest AoI) to the tip (lowest AoI). The purpose for washout is to ensure the wing root stalls first, allowing for aileron authority near the unstalled tip of the wing.

What you're thinking about are differential ailerons or Frise ailerons. Both do different things but for the same purpose: reducing adverse yaw.
- Differential ailerons have a larger up travel than down travel. This increases the drag on the descending wing, reducing adverse yaw.
- Frise ailerons have an offset hinge, so that the leading edge of the raised aileron extends below the bottom surface of the wing, increasing drag on the descending wing and reducing adverse yaw. These ailerons also create a slot on the lowered aileron, re-energizing the boundary layer and potentially increasing aileron effectiveness on the rising wing at high AoA.

I'm not sure that a twist (washout) in the aileron would reduce adverse yaw on its own.

Either that or I'm completely confused about what you're talking about.

/thread drift.

Cam,

Yes, the frise aileron, bungee, partial differential aileron, washout (fly the aileron section of the wing at less incidence), etc etc are all half attempts at eliminating adverse yaw. Only Fred Wieck's Ercoupe actually did it.

My burn with the half baked is that it makes pilots truely believe they can turn safely without rudder. You can turn safely without aileron. You cannot turn safely without rudder, except with the far better engineered Ercoupe. Look behind the seat at the bellcrank and pushrod system. Move the control wheel. In a bank to the right, the left aileron will go down slightly at first and the left aileron will go up a lot. As you roll in more right bank, the left and right aileron will move about the same. The little part that pushes the two aileron pushrods has a variable camber rather than keeping the same curvature throughout.

So, unless you are flying an older airplane without modern halfbaked wing engineering, you can't learn much about adverse yaw until you bank 45% left,right,left, etc, doing Dutch Rolls. Only with that amount of bank will the adverse yaw problem rear its ugly head. So, until you have an upset or need to miss an obstruction too high to climb over, you won't realize you have to stand on the rudder in a steep turn and you especially need to stand on the rudder to get the down wing back up. In your Pacer, you will have to stretch that bungee quite a bit. None of the adverse yaw mitigation engineering actually works in a need to turn bind. You have to seriously use mainly rudder or at least lead rudder.

All these old and modern airplanes are well designed and built. They can't, except in what Wolfgang called the safely airplane, do everything for us.

contactflying wrote:Cam,

Yes, the frise aileron,<snip>, partial differential aileron, <snip>, etc etc are all half attempts at eliminating adverse yaw.

Yes. Designed to reduce or eliminate adverse yaw.

contactflying wrote:bungee

This is not an attempt at eliminating adverse yaw. This is an attempt to automatically compensate for adverse yaw.

Seems like semantics, but words have meanings in engineering.

contactflying wrote:washout (fly the aileron section of the wing at less incidence)

Washout does not reduce adverse yaw and was not designed to reduce adverse yaw.

Unless you’re literally saying to not use the ailerons (which is an extremely confusing way to communicate your concept, misusing the engineering terminology completely and setting yourself up for a very confused audience). If this is what you’re saying, it’s not a design to reduce or eliminate adverse yaw, it’s a pilot’s compensation strategy to reduce or eliminate adverse yaw. Though based on your previous posts on the subject I think you’re more concerned with stalling the climbing (aileron down) wing, which has nothing to do with adverse yaw.

Again, words have meanings.

As a side note, I picked up a brand new (~ 25 hours on the tach) Cessna 185 in 1986. On the first walk around,, I noted that the left aileron faired with the wingtip, But was not faired with the outboard end of the flap. Basically, the aileron was pure straight, as opposed to the outboard end sweeping up slightly.

I pointed this out to Maintenance, and they scratched their heads and said go fly it....it’s literally a brand new airplane.

I flew it and everything seemed normal....stalled straight in all configurations, etc. Took the plane home and flew it that way for ~ 1000 hours. But that issue always bugged me.

One day, I had the plane in ANC for a 100 hour, and I pointed this issue out to our new Chief of Maintenance. He scratched his head and said “that’s not right.....how does it fly?”. I told him, and he said it’s gonna get fixed. So, I left the plane there for a few weeks, and when I came back, the left aileron faired at both ends.....nice.

I did a maintenance test flight, and the plane was rigged just right.

In the meantime, I’d found two other very late model 185s with this same issue. All these planes hade Robertson STOL kits, like mine did. We could only assume that somewhere along the line, Robertson’s left aileron jig got tweaked or modified somehow....assuming Robertson used a jig.

Anyway, after the plane was fixed and re-rigged, it flew just fine, actually couldn’t tell the difference, though the plane was probably a tiny bit faster. Change in stall? None I could detect.

MTV

Thanks Cam. I am not an engineer and am always somewhat confused. Whatever caused the change from older airplanes that absolutely would not allow any pilot to imagine he could turn safely without rudder is dangerous without indoctrination in good rudder usage. So with washout we stall the wing root and keep the ailerons active so the pilot May? survive without using rudder properly.

And then there are frise ailerons that hide the adverse yaw, which is still there, in shallow and even medium banked turns. Designed safety needs go all the way. My son says controls, any controls, on computer directed cars will make them unsafe. I argue with him but expect he is right. The computer controlled airplanes are certainly safer than pilots who don't use the rudder properly.

The rudder is there to completely deal with adverse yaw. The rudder is also there to get the nose down and around smarty in a steep turn (skid perhaps but the nose should be well down) and to get the down wing back up smarty before putting it through a wire. The rudder is there to keep a directed course to the centerline on final. Aileron, and the hidden adverse yaw, just screws things up when used on final..