Discussion:
Fowler flaps?
(too old to reply)
TJ400
2006-05-11 20:31:11 UTC
Permalink
I am presently in the process of converting a PA-22 to a Sportsman 2+2.
Plans call for new wings to be buillt from scratch and I am
considering the use of Fowler flaps rather than conventional for
greater lift, reduced stall speed, steeper landing approach and better
angle of attack/ visibility while landing. Can anyone suggest a link
or reference for plans or explanation of construction of such flaps?.
Have found little on construction techniques on the net to date.
Any and all help is greatly appreciated. TJ
f***@wi.rr.com
2006-05-11 21:19:51 UTC
Permalink
TJ
A very good book "The Flower Flap". A engineering hand book, By Harland
Fowler.
It has 90 pages of information about the history and engineering
Info. about the Fowler Flap. A good book for the aircraft Designers
and Builders.
I have used it for many years.

Sold by Aircraft Design Inc. Was $42.00
www.aircraftdesigns.com
Listed under books and software.

Larry Fitzgerald

www.fitzair.net

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Post by TJ400
I am presently in the process of converting a PA-22 to a Sportsman 2+2.
Plans call for new wings to be buillt from scratch and I am
considering the use of Fowler flaps rather than conventional for
greater lift, reduced stall speed, steeper landing approach and better
angle of attack/ visibility while landing. Can anyone suggest a link
or reference for plans or explanation of construction of such flaps?.
Have found little on construction techniques on the net to date.
Any and all help is greatly appreciated. TJ
jerry wass
2006-05-12 04:07:14 UTC
Permalink
Do the plans call for enlarging the horiz stabilizer as well--??
Post by f***@wi.rr.com
TJ
A very good book "The Flower Flap". A engineering hand book, By Harland
Fowler.
It has 90 pages of information about the history and engineering
Info. about the Fowler Flap. A good book for the aircraft Designers
and Builders.
I have used it for many years.
Sold by Aircraft Design Inc. Was $42.00
www.aircraftdesigns.com
Listed under books and software.
Larry Fitzgerald
www.fitzair.net
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Post by TJ400
I am presently in the process of converting a PA-22 to a Sportsman 2+2.
Plans call for new wings to be buillt from scratch and I am
considering the use of Fowler flaps rather than conventional for
greater lift, reduced stall speed, steeper landing approach and better
angle of attack/ visibility while landing. Can anyone suggest a link
or reference for plans or explanation of construction of such flaps?.
Have found little on construction techniques on the net to date.
Any and all help is greatly appreciated. TJ
TJ400
2006-05-12 05:25:41 UTC
Permalink
yes, horizontal stabs are enlarged.... each feather opened near mid
and approx 10" are added to each...

I'll order the book..thanks
J.Kahn
2006-05-13 04:58:25 UTC
Permalink
Complete and total waste of effort I would say. Fowler flaps provide
the same section cl increase as slotted flaps, from roughly 1.6 to 2.6.
The only difference is the fowler flap increases area somewhat. If
you work it out using the calculation to estimate stall speed and
factoring the increase in area or say 10%, the benefit of the increase
in area with fowler flaps extended will be tiny on an airplane that
already has generous wing area, maybe two knots. Not much benefit for a
whole lot of design, analysis and testing. They are more likely to
provide a useful benefit on a high performance airplane with small wings
that needs all the extra lift it can get because the landing energy is
way up there..

Just use a slotted flap on hinge arms. In fact, if you really want to
make changes to the flaps to get more lift, you will likely get more
benefit by making the slotted flap into double slotted type by adding a
fixed slat to the leading edge, than by building an elaborate fowler
track system.

John
Post by jerry wass
Do the plans call for enlarging the horiz stabilizer as well--??
Post by f***@wi.rr.com
TJ
A very good book "The Flower Flap". A engineering hand book, By Harland
Fowler.
It has 90 pages of information about the history and engineering
Info. about the Fowler Flap. A good book for the aircraft Designers
and Builders.
I have used it for many years.
Sold by Aircraft Design Inc. Was $42.00
www.aircraftdesigns.com
Listed under books and software.
Larry Fitzgerald
www.fitzair.net
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Post by TJ400
I am presently in the process of converting a PA-22 to a Sportsman 2+2.
Plans call for new wings to be buillt from scratch and I am
considering the use of Fowler flaps rather than conventional for
greater lift, reduced stall speed, steeper landing approach and better
angle of attack/ visibility while landing. Can anyone suggest a link
or reference for plans or explanation of construction of such flaps?.
Have found little on construction techniques on the net to date.
Any and all help is greatly appreciated. TJ
TJ400
2006-05-13 12:55:28 UTC
Permalink
Hi John.. can you suggest a link with a good illustration/ plans,
please (anything is welcome)... looking for anything right about
now.... I've been told by someone who has built and flown a 2+2 from a
PA-22 (certified Aircraft Mechanic) that the limitations of this
airplane as a bush plane is not it's capability of taking off and
getting out of small lakes, but rather landing and finally touching
down after flare out.... with Super Cub wings installed, this thing is
a kite and seems to take forever to finally touch down...

He claims with a system like a fowler not so much is the change in
stall speed important but rather a steeper approach so flaring as close
to the downwind end of the lake/ obstacle is possible... This will
provide better nose down attitude for vision also...

The gentleman mentioned above and myself are now building a pair of
sister airplanes together in the same shop... I'm trying to gather a
little research on the flap dilemma while he shows me how to build the
rst of a 2+2...

I welcome ANY and ALL advice regarding this subject...

TJ
Stealth Pilot
2006-05-13 15:30:15 UTC
Permalink
Post by TJ400
Hi John.. can you suggest a link with a good illustration/ plans,
please (anything is welcome)... looking for anything right about
now.... I've been told by someone who has built and flown a 2+2 from a
PA-22 (certified Aircraft Mechanic) that the limitations of this
airplane as a bush plane is not it's capability of taking off and
getting out of small lakes, but rather landing and finally touching
down after flare out.... with Super Cub wings installed, this thing is
a kite and seems to take forever to finally touch down...
He claims with a system like a fowler not so much is the change in
stall speed important but rather a steeper approach so flaring as close
to the downwind end of the lake/ obstacle is possible... This will
provide better nose down attitude for vision also...
The gentleman mentioned above and myself are now building a pair of
sister airplanes together in the same shop... I'm trying to gather a
little research on the flap dilemma while he shows me how to build the
rst of a 2+2...
I welcome ANY and ALL advice regarding this subject...
TJ
go find a cessna 150. this has the simplest fowler flap setup going.
at 40 degrees of flaps it works well.
btw while you are at it put frise ailerons on as well.

Stealth Pilot
L***@caspercityauto.com
2006-05-13 15:54:32 UTC
Permalink
Post by TJ400
with Super Cub wings installed, this thing is
a kite and seems to take forever to finally touch down... <<

Spoilers like the old T'cart's? A WHOLE lot easier to do than Fowlers
or even slotted flaps. Besides Spoilers are better for glide path
control than flaps anyway - IMHO

For ideas go look at some gliders.
===============
Leon McAtee
Wayne Paul
2006-05-13 18:55:11 UTC
Permalink
Post by L***@caspercityauto.com
with Super Cub wings installed, this thing is a kite and seems to take
forever to finally touch down... <<
Spoilers like the old T'cart's? A WHOLE lot easier to do than Fowlers
or even slotted flaps. Besides Spoilers are better for glide path
control than flaps anyway - IMHO
For ideas go look at some gliders.
Most homebuilt sailplanes use flaps for glide slope control. The reason?
Ease of construction.

Udo Rumpf's version of an HP-18 is a good example.
Loading Image...
These are not Fowler flaps, they are simple hinge flaps. They change the
glide slop from 40 to 1, to about 3 to 1. You won't float with these babes
down!

Wayne
HP-14 N990 "6F"
http://www.soaridaho.com/Schreder/HP-14/N990/N990.html
J.Kahn
2006-05-18 23:41:42 UTC
Permalink
Post by L***@caspercityauto.com
Post by TJ400
with Super Cub wings installed, this thing is
a kite and seems to take forever to finally touch down... <<
Spoilers like the old T'cart's? A WHOLE lot easier to do than Fowlers
or even slotted flaps. Besides Spoilers are better for glide path
control than flaps anyway - IMHO
For ideas go look at some gliders.
===============
Leon McAtee
As a glider pilot I agree. This is a perfect suggestion! TJ, find
someone with a set of Wag Aero Sportsman 2+2 plans and copy the spoiler
arrangement.

For the flaps, just copy a Citabria or Super Cub setup. Flaps along
with spoilers give incredible glide path control. You can set up a max
lift configuration with flaps and a moderate power setting to limit
sink, and use the spoilers to fly to the exact spot you want to touch
down. Just like a glider.

The ability to place the airplane exactly where you want it that you get
with spoilers will just about eliminate your fear of engine outs as long
as there is a reasonably sized open space within gliding range.


John
Highflyer
2006-05-15 04:24:38 UTC
Permalink
Post by TJ400
Hi John.. can you suggest a link with a good illustration/ plans,
please (anything is welcome)... looking for anything right about
now.... I've been told by someone who has built and flown a 2+2 from a
PA-22 (certified Aircraft Mechanic) that the limitations of this
airplane as a bush plane is not it's capability of taking off and
getting out of small lakes, but rather landing and finally touching
down after flare out.... with Super Cub wings installed, this thing is
a kite and seems to take forever to finally touch down...
He claims with a system like a fowler not so much is the change in
stall speed important but rather a steeper approach so flaring as close
to the downwind end of the lake/ obstacle is possible... This will
provide better nose down attitude for vision also...
The gentleman mentioned above and myself are now building a pair of
sister airplanes together in the same shop... I'm trying to gather a
little research on the flap dilemma while he shows me how to build the
rst of a 2+2...
I welcome ANY and ALL advice regarding this subject...
TJ
Take a look at the flaps on any Cessna built in the last fifty years. That
is a Fowler type flap. That is why you need the tracks and rollers. They
allow the flap to extend to the rear while it is deflecting.

You can do almost as well much easier by merely dropping the hinge line for
the flaps some distance below the wing. See, for example, the flaps on a
Husky. That will give you 98% of the advantages of a full Fowler Flap with
a lot less engineering and a lot less mechanism.

Remember the cardinal rule in aircraft design "Simplificate and add
lightness!"

Highflyer
Highflight Aviation Services
Pinckneyville Airport ( PJY )

Remember, the r.a.h. Flyin at Pinckneyville is this weekend, May 19, 20, and
21. Start flightplanning now.
TJ400
2006-05-13 12:55:44 UTC
Permalink
Hi John.. can you suggest a link with a good illustration/ plans,
please (anything is welcome)... looking for anything right about
now.... I've been told by someone who has built and flown a 2+2 from a
PA-22 (certified Aircraft Mechanic) that the limitations of this
airplane as a bush plane is not it's capability of taking off and
getting out of small lakes, but rather landing and finally touching
down after flare out.... with Super Cub wings installed, this thing is
a kite and seems to take forever to finally touch down...

He claims with a system like a fowler not so much is the change in
stall speed important but rather a steeper approach so flaring as close
to the downwind end of the lake/ obstacle is possible... This will
provide better nose down attitude for vision also...

The gentleman mentioned above and myself are now building a pair of
sister airplanes together in the same shop... I'm trying to gather a
little research on the flap dilemma while he shows me how to build the
rest of a 2+2...

I welcome ANY and ALL advice regarding this subject...

TJ
Cy Galley
2006-05-14 11:43:36 UTC
Permalink
Learn to slip!
Post by TJ400
Hi John.. can you suggest a link with a good illustration/ plans,
please (anything is welcome)... looking for anything right about
now.... I've been told by someone who has built and flown a 2+2 from a
PA-22 (certified Aircraft Mechanic) that the limitations of this
airplane as a bush plane is not it's capability of taking off and
getting out of small lakes, but rather landing and finally touching
down after flare out.... with Super Cub wings installed, this thing is
a kite and seems to take forever to finally touch down...
He claims with a system like a fowler not so much is the change in
stall speed important but rather a steeper approach so flaring as close
to the downwind end of the lake/ obstacle is possible... This will
provide better nose down attitude for vision also...
The gentleman mentioned above and myself are now building a pair of
sister airplanes together in the same shop... I'm trying to gather a
little research on the flap dilemma while he shows me how to build the
rest of a 2+2...
I welcome ANY and ALL advice regarding this subject...
TJ
TJ400
2006-05-14 16:13:14 UTC
Permalink
"Learn to slip!"

now that's it, heck I'll forget about flap construction completely and
slip on approach for the rest of my flying days! Makes for quicker
build time...

love unusual attitudes, at low airspeeds, close to ground level, with
floats attached...:-)


need to look at the 150 Cessna flap construction more closely...
thanks..
cavelamb
2006-05-16 23:05:42 UTC
Permalink
Post by TJ400
"Learn to slip!"
now that's it, heck I'll forget about flap construction completely and
slip on approach for the rest of my flying days! Makes for quicker
build time...
love unusual attitudes, at low airspeeds, close to ground level, with
floats attached...:-)
need to look at the 150 Cessna flap construction more closely...
thanks..
Don't.

None of it "looks" anywhere near strong enough...
Drew Dalgleish
2006-05-17 02:05:38 UTC
Permalink
Post by TJ400
"Learn to slip!"
now that's it, heck I'll forget about flap construction completely and
slip on approach for the rest of my flying days! Makes for quicker
build time...
love unusual attitudes, at low airspeeds, close to ground level, with
floats attached...:-)
need to look at the 150 Cessna flap construction more closely...
thanks..
My rebel slips just fine on floats thanks. It's a good thing cuz the
flaperons don't really make much of a difference. Of course if you're
close to the ground in a floatplane you might have other worries. I
don't think you appreciate how much drag there is from your floats and
how easy it is to land in a lake that you have no hope of ever taking
off from again.
TJ400
2006-05-17 11:29:55 UTC
Permalink
I was being humerous and do appreciate drag from a slip, I just prefer
not needing to slip on approach but having a great flap system where
creating drag, lowering stall speed and creating lift are all part of
it's design.... the fowler or others I'm learning about, do that....
not fond of spoiler type devices because stall goes up... not fond of
slipping because it's an attitude conducive to spins, if airspeed is
not correct... just looking for pure saftey and practicality... still
open to suggestions...

thanks again..

tj..
Drew Dalgleish
2006-05-17 14:51:11 UTC
Permalink
Post by TJ400
I was being humerous and do appreciate drag from a slip, I just prefer
not needing to slip on approach but having a great flap system where
creating drag, lowering stall speed and creating lift are all part of
it's design.... the fowler or others I'm learning about, do that....
not fond of spoiler type devices because stall goes up... not fond of
slipping because it's an attitude conducive to spins, if airspeed is
not correct... just looking for pure saftey and practicality... still
open to suggestions...
thanks again..
tj..
I got the humor I'm trying to say that float planes don't need more
drag. Lowering stall speed is a good thing but you only need a little
flap for that. Something else to consider is when you select full
flaps can you still open the doors? Float planes end up on their
backs fairly regularly usually without any injuries but if you can't
get out because of the flaps you're in big trouble.
TJ400
2006-05-17 18:10:04 UTC
Permalink
"Float planes end up on their
backs fairly regularly usually without any injuries but if you can't
get out because of the flaps you're in big trouble."


you've given me another design characteristic.... an important one at
that... thanks
Montblack
2006-05-17 23:54:54 UTC
Permalink
("TJ400" wrote)
Post by TJ400
"Float planes end up on their backs fairly regularly usually without any
injuries but if you can't get out because of the flaps you're in big
trouble."
you've given me another design characteristic.... an important one at
that... thanks
A self-righting float plane?


Montblack :-)
UltraJohn
2006-05-19 01:15:41 UTC
Permalink
("TJ400maneuver>>> "Float planes end up on their backs fairly regularly
usually without any
Post by TJ400
injuries but if you can't get out because of the flaps you're in big
trouble."
you've given me another design characteristic.... an important one at
that... thanks
A self-righting float plane?
Montblack :-)
Eskimo roll (as in a kayak maneuver),
John

L***@caspercityauto.com
2006-05-17 23:10:23 UTC
Permalink
not fond of spoiler type devices because stall goes up... <<
Only if you use them! If you find yourself short with flaps hung out
and retract them your CL goes - down - and so do you until the airspeed
picks up. In the same situation with spoilers the CL goes up and the
glide angle flattens out.

Of course if you are 100% confident that the power is going to be there
just drag it in on the prop..........

Think air brake rather than spoiler if that helps.
==============
Leon McAtee
Just my opinion
\ Retracting spoilers
\
\....
`````......
....... Retracting flaps
```````.......
\
\....
``````
f***@spamcop.net
2006-05-18 01:37:35 UTC
Permalink
Post by f***@wi.rr.com
TJ
A very good book "The Flower Flap". A engineering hand book, By Harland
Fowler.
It has 90 pages of information about the history and engineering
Info. about the Fowler Flap. A good book for the aircraft Designers
and Builders.
I have used it for many years.
Sold by Aircraft Design Inc. Was $42.00
www.aircraftdesigns.com
Listed under books and software.
Is there anything similar for Junkers flaps.?
--
FF
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