Slats and Fowler Flaps On Light Plane

I feel there is a real advantage to the use of slats and flaps in
order to have things happen slowly during landing and yet still have a
good cruise speed. Of course the problem is in the complexity and the
extra weight. For rails I was thinking about something like standard
kitchen drawer rails or perhaps a tube within a tube design. I
wouldn't think their would be a lot of force on the slat at low
takeoff speeds so the structure wouldn't have to be bullet proof,
their would probably be a lot more force on the flaps though. I
haven't been able to find information if the necessary airplane
hardware is available commercially, perhaps it would have to be custom
made. Any ideas on how to go about building something like this?

Brock

On 25 Jul 2003 06:51:08 -0700, (Brock) wrote:

I feel there is a real advantage to the use of slats and flaps in
order to have things happen slowly during landing and yet still have a
good cruise speed. Of course the problem is in the complexity and the
extra weight. For rails I was thinking about something like standard
kitchen drawer rails or perhaps a tube within a tube design. I
wouldn't think their would be a lot of force on the slat at low
takeoff speeds so the structure wouldn't have to be bullet proof,
their would probably be a lot more force on the flaps though. I
haven't been able to find information if the necessary airplane
hardware is available commercially, perhaps it would have to be custom
made. Any ideas on how to go about building something like this?

Brock
+++++++++++++++++++++++++++++++++++++++

My FEELING is....
You can't safely get there from here.

Given the nature and level of your question....
perhaps you should look at aircraft designs
that you could copy or adapt to whatever
you have in mind.

Other than that, a degree in aero engineering might helpful
to bring you back to reality before someone is harmed.


Barnyard BOb -- stranger than fiction

"Brock" wrote in message
om...
I feel there is a real advantage to the use of slats and flaps in
order to have things happen slowly during landing and yet still have a
good cruise speed. Of course the problem is in the complexity and the
extra weight. For rails I was thinking about something like standard
kitchen drawer rails or perhaps a tube within a tube design. I
wouldn't think their would be a lot of force on the slat at low
takeoff speeds so the structure wouldn't have to be bullet proof,
their would probably be a lot more force on the flaps though. I
haven't been able to find information if the necessary airplane
hardware is available commercially, perhaps it would have to be custom
made. Any ideas on how to go about building something like this?

Brock

You could copy the flap design from the RV-10 or the Glasair series. Good
luck on the slats - those have to be built to very tight tolerances so they
operate at the same time. Differential slat extension has killed quite a few
people. Also, more than a few people have been killed by having a slat
depart the airframe in flight.

Vortex generators might be a safer alternative.

KB

Earlier, (Brock) wrote:

For rails I was thinking about
something like standard kitchen
drawer rails or perhaps a tube
within a tube design. I wouldn't
think their would be a lot of
force on the slat...

The two factors that might surprise you are the worst-case loads on an
extended slat at design limit loading, and the consequences of failure
of the actuators or the support rails. Taken together, they suggest
that the structure should be about as bulletproof as any other element
of primary structure.

...perhaps it would have to be
custom made.

Almost certainly the case. Fortunately, the raw materials (bearings,
steel, aluminum) are all relatively cheap and plentiful. Let the
Aircraft Spruce (or Wicks) catalog be your guide and playground.

Any ideas on how to go about
building something like this?

Make a sectional model out of garbage (plywood, masonite, nails) and
keep modifying it until it gives good motion.

Then make a prototype of one of the actuator/support stations, and
load test it to validate that it supports loadings about 1.5x of the
maximum expected.

Then make a full-scale prototype and test it on the experimental
aircraft of your choice. Good luck.

The slats on the Me-109 (or Bf-109) might be a god model to start
from. I understand that they're just spring-loaded so they pop out
when the pressure at the stagnation point goes below a certain value.

Thanks, and best regards to all

Bob K.
http://www.hpaircraft.com/hp-24

Le Vendredi 25 Juillet 2003 18:50
Kyle Boatright a écrit:



You could copy the flap design from the RV-10 or the Glasair series.
Good luck on the slats - those have to be built to very tight
tolerances so they operate at the same time. Differential slat
extension has killed quite a few
people. Also, more than a few people have been killed by having a
slat depart the airframe in flight.

The slat MUST be built with mecanical link to operate together. See
what you can read about french design Morane Rallye ('60 to '80).
This plane had all the features you want.

By
--
Philippe Vessaire Ò¿Ó¬

Brock wrote:
kitchen drawer rails or perhaps a tube within a tube design. I
wouldn't think their would be a lot of force on the slat at low
takeoff speeds so the structure wouldn't have to be bullet proof,

If there isn't a lot of force on them then they aren't doing you any good.


--
----Because I can----
http://www.ernest.isa-geek.org/
------------------------

Brock wrote:

I feel there is a real advantage to the use of slats and flaps in
order to have things happen slowly during landing and yet still have a
good cruise speed. Of course the problem is in the complexity and the
extra weight. For rails I was thinking about something like standard
kitchen drawer rails or perhaps a tube within a tube design. I
wouldn't think their would be a lot of force on the slat at low
takeoff speeds so the structure wouldn't have to be bullet proof,
their would probably be a lot more force on the flaps though. I
haven't been able to find information if the necessary airplane
hardware is available commercially, perhaps it would have to be custom
made. Any ideas on how to go about building something like this?

Brock

Whereas the Helio Courier and Morane Rallye (among others), and their
slats, are discussed elsewhere in the thread; I'll just mention that all
of the high wing Cessna aircraft with which I am familiar have single
slotted Fowler flaps. I have no idea how much performance you would
gain with double slotted Fowler flaps, and doubt that they would add
much weight; but believe that they would be a real pain in the neck to
build s the dimensions would need to be held closely in order for the
slots to have the correct proportions and the additional surfaces would
need to be finished.

Peter

Flew em both. Worked fine.

Big John

On Fri, 25 Jul 2003 18:56:13 GMT, "Capt. Doug"
wrote:

Philippe Vessaire wrote in message The slat MUST be built with mecanical
link to operate together. See
what you can read about french design Morane Rallye ('60 to '80).
This plane had all the features you want.

For the proper way to design slats, study the Sabreliner and the
Helio-Courier, neither of which is mechanically interconnected, or French.

D. (couldn't resist)

On Fri, 25 Jul 2003 23:27:14 GMT, Richard Lamb
wrote:

WHAT actuators, Bob.

Most slats are deployed by aerodynamic forces,
not mechanical ones...


The Pegazair has automatic, independent slats. Because they are
controlled by lift, or lack thereof, they only come out when needed,
and sometimes they are only needed on one side.
It is a Dedalius (spelling?) style wing - also supplied as an add-on
to the CH701, and, I believe, other planes. No springs either.


Bob Kuykendall wrote:

Earlier, (Brock) wrote:

For rails I was thinking about
something like standard kitchen
drawer rails or perhaps a tube
within a tube design. I wouldn't
think their would be a lot of
force on the slat...

The two factors that might surprise you are the worst-case loads on an
extended slat at design limit loading, and the consequences of failure
of the actuators or the support rails. Taken together, they suggest
that the structure should be about as bulletproof as any other element
of primary structure.

...perhaps it would have to be
custom made.

Almost certainly the case. Fortunately, the raw materials (bearings,
steel, aluminum) are all relatively cheap and plentiful. Let the
Aircraft Spruce (or Wicks) catalog be your guide and playground.

Any ideas on how to go about
building something like this?

Make a sectional model out of garbage (plywood, masonite, nails) and
keep modifying it until it gives good motion.

Then make a prototype of one of the actuator/support stations, and
load test it to validate that it supports loadings about 1.5x of the
maximum expected.

Then make a full-scale prototype and test it on the experimental
aircraft of your choice. Good luck.

The slats on the Me-109 (or Bf-109) might be a god model to start
from. I understand that they're just spring-loaded so they pop out
when the pressure at the stagnation point goes below a certain value.

Thanks, and best regards to all

Bob K.
http://www.hpaircraft.com/hp-24

Ernest Christley wrote:

Brock wrote:
kitchen drawer rails or perhaps a tube within a tube design. I
wouldn't think their would be a lot of force on the slat at low
takeoff speeds so the structure wouldn't have to be bullet proof,

If there isn't a lot of force on them then they aren't doing you any good.

--
----Because I can----
http://www.ernest.isa-geek.org/
------------------------

When the slats pop out on the Helio Courier based here,
it sounds like a shotgun. Loud BOOM!

There is indeed a lot of force here...