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TFF

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Apr 28, 2010
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The STOL people prefer the manual flaps if possible because they can get the movement faster. They want extra lift or want to kill lift fast. It’s not a big plane so leverage should not be an issue. I have a friend who pretty much has to have electric flaps but his body was destroyed in a car crash. It’s amazing that he can fly at all. If you met him away from the airport, you would say no way. If it’s well designed manual will be better than a conversion.
 

Dalmo

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Sep 6, 2021
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I'm liking the idea of giving the manual flaps 12 months worth of trial before making a final decision. I can sense the support for manual flaps is very strong and backed by experience, which is what I lack, so that's what I'll do - give the manual flaps a go. If after 12 months I don't like them, I believe the actuator approach suggested by Daleandee sounds like a good place to start.
Many thanks to all - you've opened my eyes and mind to doing things differently.
 

Victor Bravo

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Jul 30, 2014
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KWHP, Los Angeles CA, USA
Dalmo, you are absolutely on the right track by starting with the simple solution and leaving your options open to add the other system later.

I am very much opinionated about this subject because I'm actually "in the manual flap business" outside of this E-AB forum. What I can add is that the physical feedback through the manual flap control is something that offers a significant advantage too, outside of the other factors.

It's the same principle as what experienced drivers say about some sportscars and race cars giving you a physical sensation or force feedback through the steering or brakes.

The car "talks to you" through the steering wheel, etc. etc.

It's a shame that I can't write that sentence using Jackie Stewart's thick Scottish brogue (with the old ABC Wide World of Sports theme music playing in the background)... but you get the point :)

The thrill of victory- and the agony of the flaps!
 

Dalmo

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Sep 6, 2021
Messages
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It had to happen eventually. At least no one told me to checkout Ghostbusters Engineering, or something similar.

I have to say, I'm picking up on the passion that you folk have towards manual flaps, especially comparing it to "feeling" a car through its steering wheel, which is how I taught my 3 sons to drive. I'm a relative newbie, so something I'll look to develop in my flying - many thanks.
 

Dalmo

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Sep 6, 2021
Messages
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One of the things I noticed about electric flaps , like Ron Popiel they tend to be used as “set it and forget it” In aviation those words seem to be deadly.
I can understand what you mean. Electric flaps can be left on purposely, or forgotten pretty easily with not-too-pleasant consequences. Certainly harder to forget a big stick-like handle hanging just near your left ear.
 

Tiger Tim

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Apr 26, 2013
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Thunder Bay
“set it and forget it” In aviation those words seem to be deadly.
They just mean you have to ratchet your discipline up a notch or two. Plenty of planes have electric (or other non-manual) flaps and we’re only picking out negative anecdotes because that’s the current discussion subject.

By all means, see how the manual flaps work in your plane that was designed for them, but also recognize all it takes to install and operate electric flaps sometime down the road is the right level of responsibility.
 

Dalmo

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Sep 6, 2021
Messages
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Sounds fair enough. I'm just looking forward to the build, and once its flying, operating it as safely and enjoyably as possible.
 

WonderousMountain

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Apr 10, 2010
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Clatsop, Or
So turns out when you are adding flaps to an old design, this comes up. AnyOne have a preferred three position overhead lever to borrow ideas from? Thinking something like 0-24-48 degree, or whatever works for 16% flaps on a 37 & 1/2" Chord.
 

jedi

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Aug 8, 2009
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Sahuarita Arizona, Renton Washington, USA
Lots of examples. CGS Hawk. Adventura. Numerous other UL types if you are referring to the linkaage design.

16% and 48 degrees is a lot of flap. I would like 4 positions or perhaps even add a takeoff position of 5 degrees. Then why not a negative 5 also.
 

WonderousMountain

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Apr 10, 2010
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Clatsop, Or
A four position lever is good by me,
( 0 - 15 - 30 - 45 ). The 45 is a built
in air brake. Up flap setting doesn't
really appeal to me, Wood & Fabric.
At least not while there's so much to do.

Sincerely,
CK LouPai
 

Dan Thomas

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Sep 17, 2008
Messages
6,606
The electric flaps in the Cessnas are way more hassle, maintenance-wise, than the manual flaps. Limit switches and the panel controls are a major cause of troubles. For small airplanes, avoiding electrical systems where possible is a good thing. They add weight and complexity and cost.

My old Auster had manual flaps, and I could land and stop it in 200 feet by dumping the flaps on touchdown and hitting the brakes. Can't do that with electric flaps. There were many times I wished for manual flaps in the Cessnas, especially in a crosswind where you want to get rid of as much lift as possible after touchdown. Those flaps make the most lift at 20°, most drag at 40°, and as they retract slowly they pass through 20° and generate more lift. That's no good when you're trying to get weight on the wheels.

Cessna never installed electric flaps in the 180 and 185. There were good reasons for that. Besides, real pilots flew them:)
 

Lendo

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Feb 6, 2013
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907
Location
Brisbane
Speaking of Flaps and the fact Airfoil Turbulence starts at 60% of the Airfoil, I was wondering has anyone considered 40% of Flap to help reduce Landing speed?
George
 

Dan Thomas

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Sep 17, 2008
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6,606
Speaking of Flaps and the fact Airfoil Turbulence starts at 60% of the Airfoil, I was wondering has anyone considered 40% of Flap to help reduce Landing speed?
George
It's done all the time. Landing speed is a function of stall speed, since the flaps will usually reduce the stall and you can touch down at slower speed, not far above the stall. Here's the chart of stall speeds for various flap settings in the Cessna 150L:

1639526168321.png

So the zero bank angle unaccelerated stall is 55 MPH, flaps up, and that drops a big bunch to 49 at 20° and a tiny bit more at 40°. Like I said, the 20° setting improves the lift a lot, and the rest after that is mostly drag, useful for steepening the approach without picking up speed.

That's the 150. Other airplanes will have flaps that have different effects on the stall.
 
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