Frise ailerons on sailplanes

I was thinking recently about ground loops and flaperons and
adverse yaw and crosswinds. I can understand how
one needs a rudder for sideslips, but beyond that:

Is anyone making a modern competition glider without adverse yaw
using frise ailerons?
How about one that had no ailerons but just spoilers for roll?

Frise ailerons are made so that when one aileron goes down and
increases drag, the other aileron going "up" has a drag
edge on the bottom which increases drag on the opposite side
equally. So when the ailerons are deflected, there is
no adverse yaw, only increased drag on both wings equally.

Neat on the Duchess and the Aero Commander (twin engine planes)
but haven't heard of it in competition gliders.
Also haven't heard of rudder-aileron interconnect for gliders.

I have heard that some big jets, perhaps 737 and such, use spoilers
for additional roll authority as well.
And the U-2 was rumored to have twisting trailing edge landing gear,
so landing in a crosswind in a crab was fine.

The aircoupe combined a lot of these features to make a plane without
a rudder.

Have gliders other than the MDM-1 Fox or SZD 22C Mucha
tried frise ailerons?
A friend is building a Carbon Dragon,
which uses flaperons. Although that sounds great (nice speed
range) I wonder about the adverse yaw.

Ok, ok, maybe a frise type settup isn't aerodynamically efficient
(since there is extra drag during each roll in/out) but then again
lots of rudder during a roll isn't that efficient either.
Did some sailplane designer do a bunch of math and conclude
that frise ailerons, or using spoilers only, just wasn't
gonna work for sailplanes? Or has it just not been done generally...

The Mucha 22C took 1st place in the 1958 Standard Class world championships.
(according to the sailplanedirectory).
Was this the last time frise ailerons made a "splash" in gliding?
--

------------+
Mark J. Boyd

No one wants increased drag on the wing if you can avoid it with the rudder.

--
Bert Willing

ASW20 "TW"


"Mark James Boyd" a écrit dans le message de news:
421d8c46$1@darkstar...
I was thinking recently about ground loops and flaperons and
adverse yaw and crosswinds. I can understand how
one needs a rudder for sideslips, but beyond that:

Is anyone making a modern competition glider without adverse yaw
using frise ailerons?
How about one that had no ailerons but just spoilers for roll?

Frise ailerons are made so that when one aileron goes down and
increases drag, the other aileron going "up" has a drag
edge on the bottom which increases drag on the opposite side
equally. So when the ailerons are deflected, there is
no adverse yaw, only increased drag on both wings equally.

Neat on the Duchess and the Aero Commander (twin engine planes)
but haven't heard of it in competition gliders.
Also haven't heard of rudder-aileron interconnect for gliders.

I have heard that some big jets, perhaps 737 and such, use spoilers
for additional roll authority as well.
And the U-2 was rumored to have twisting trailing edge landing gear,
so landing in a crosswind in a crab was fine.

The aircoupe combined a lot of these features to make a plane without
a rudder.

Have gliders other than the MDM-1 Fox or SZD 22C Mucha
tried frise ailerons?
A friend is building a Carbon Dragon,
which uses flaperons. Although that sounds great (nice speed
range) I wonder about the adverse yaw.

Ok, ok, maybe a frise type settup isn't aerodynamically efficient
(since there is extra drag during each roll in/out) but then again
lots of rudder during a roll isn't that efficient either.
Did some sailplane designer do a bunch of math and conclude
that frise ailerons, or using spoilers only, just wasn't
gonna work for sailplanes? Or has it just not been done generally...

The Mucha 22C took 1st place in the 1958 Standard Class world
championships.
(according to the sailplanedirectory).
Was this the last time frise ailerons made a "splash" in gliding?
--

------------+
Mark J. Boyd

Mark James Boyd wrote:

I was thinking recently about ground loops and flaperons and
adverse yaw and crosswinds. I can understand how
one needs a rudder for sideslips, but beyond that:

Looking at your posts (this one and those concerning crosswind landings,
I come to the conclusion that you have a problem with correct rudder use.

Is anyone making a modern competition glider without adverse yaw
using frise ailerons?

I don't know the origin of the legend that rudder is only needed to
compensate for adverse yaw. But as a proper turn is a movement around
all three axis, you always need all three controls for a proper turn,
with or without adverse yaw.

Stefan

Since sailplanes overbank in steep turns applying the required opposite
aileron would then create even more adverse yaw.

One reason that the Carbon Dragon has full-span flaperons is that they
are driven from the root end only, avoiding the need to clutter the
wing structure with pushrods, cables, pulleys, etc.

Jonathan Pitt

Since sailplanes overbank in steep turns applying the required opposite
aileron would then create even more adverse yaw.

One reason that the Carbon Dragon has full-span flaperons is that they
are driven from the root end only, avoiding the need to clutter the
wing structure with pushrods, cables, pulleys, etc.

Jonathan Pitt

" wrote in message
ups.com...
Since sailplanes overbank in steep turns applying the required opposite
aileron would then create even more adverse yaw.

One reason that the Carbon Dragon has full-span flaperons is that they
are driven from the root end only, avoiding the need to clutter the
wing structure with pushrods, cables, pulleys, etc.

Jonathan Pitt



Full span aileron will reduce the deflection to nearly half for any given
roll rate, which reduces deflection drag. With a one stage differential
input the control performance becomes even more advantages.
Naturally it also has disadvantages. An example of that arrangement is the
DG 800 series of gliders. It has less to do with clutter.
The best compromise in my opinion is the ASW 20 and 27 arrangement.
Regards
Udo

Mark James Boyd wrote:

I was thinking recently about ground loops and flaperons and
adverse yaw and crosswinds. I can understand how
one needs a rudder for sideslips, but beyond that:


Looking at your posts (this one and those concerning crosswind
landings), I come to the conclusion that you have a problem with correct
rudder use.

Is anyone making a modern competition glider without adverse yaw using
frise ailerons?

I don't know the origin of the legend that rudder is only needed to
compensate for adverse yaw. As a proper turn is a movement around all
three axis, you always need all three controls, with or without adverse yaw.

Stefan

On 24 Feb 2005 00:11:50 -0800, Mark James Boyd wrote:

I was thinking recently about ground loops and flaperons and
adverse yaw and crosswinds. I can understand how
one needs a rudder for sideslips, but beyond that:

Is anyone making a modern competition glider without adverse yaw
using frise ailerons?
How about one that had no ailerons but just spoilers for roll?

Frise ailerons are made so that when one aileron goes down and
increases drag, the other aileron going "up" has a drag
edge on the bottom which increases drag on the opposite side
equally. So when the ailerons are deflected, there is
no adverse yaw, only increased drag on both wings equally.

Neat on the Duchess and the Aero Commander (twin engine planes)
but haven't heard of it in competition gliders.
Also haven't heard of rudder-aileron interconnect for gliders.

I have heard that some big jets, perhaps 737 and such, use spoilers
for additional roll authority as well.
And the U-2 was rumored to have twisting trailing edge landing gear,
so landing in a crosswind in a crab was fine.

The aircoupe combined a lot of these features to make a plane without
a rudder.

Have gliders other than the MDM-1 Fox or SZD 22C Mucha
tried frise ailerons?
A friend is building a Carbon Dragon,
which uses flaperons. Although that sounds great (nice speed
range) I wonder about the adverse yaw.

Ok, ok, maybe a frise type settup isn't aerodynamically efficient
(since there is extra drag during each roll in/out) but then again
lots of rudder during a roll isn't that efficient either.
Did some sailplane designer do a bunch of math and conclude
that frise ailerons, or using spoilers only, just wasn't
gonna work for sailplanes? Or has it just not been done generally...

The Mucha 22C took 1st place in the 1958 Standard Class world championships.
(according to the sailplanedirectory).
Was this the last time frise ailerons made a "splash" in gliding?

You answered your own question: Too much drag in a high performance
sailplane which spends quite a lot of its time banked in a turn in
thermals.
What's wrong with using the rudder ?
Cheers, John G.

On the subject of spoilerons,
it is a fact spoilerons have been used on a US ATC'd
glider.

It is called the J4 Javelin.
It was in series factory production in the 1970s, and
8 were made.

Competitively, it came up against the popular influx
of German fiberglas gliders that offered in the US
market very high performance gliders such as the Glasflugel
Libelles, Schleicher Asw-15 etc.

The design and engineering was done by Max Peterson,
and production was by his company Peterson Sailplane
Corporation in California. This was reported on by
Dick Johnson.

Also, in June 1973 issue of Soaring magazine there
is the article by Max Peterson, and it is cited in
the SSA Sailplane Directory of 1983.

It was a single seat fixed landing gear all metal glider
aimed at the market for recreational, club, and commercial
operation glider use.

Interestingly, I think I recall the design used the
same parts for right, left and vertical tailfin control
surfaces although I am not sure of that.

A friend of mine, the late Tom Hulings of Mid Georgia
Soaring Association (he was WWII B-17 hero, who put
one of his shotup and then gliding B17s between hedgerows
backed by rocks in England; Tom also holds the WWII
record of bringing back the most shot up bomber of
WWII to base. He was in the Eighth
Air Force).

Tom Hulings did a number of flights in the Javelin
J4. He said he wanted to consider buying one. He

told me of his flying a J4 Javelin at Bermuda High
Soaring School (as a demonstrator?).

Tom Hulings reported to me that his flying the J4 was
interesting and that he enjoyed the experience but
that he did not care to buy one: that he could fly
it without problem; but that he did not care for the
spoileron roll response feeling in that it was not
as sensitive and not as quickly roll responsive as
he liked a glider to feel yet it was completely controllable.


Dick Johnson evaluated the J4 Javelin and wrote his
evaluation. put this into your browser and read-

http://web.ukonline.co.uk/sssrcsoaring/
Spotlight_Data/Javelin/J-4_JavelinArticle.pdf

Kindest regards,

Dancing on clouds,

Keep it up!

Jim Culp USA
Asw-20C
GatorCity Florida

At 08:30 24 February 2005, Mark James Boyd wrote:
Neat on the Duchess and the Aero Commander (twin engine
planes)
but haven't heard of it in competition gliders.
Also haven't heard of rudder-aileron interconnect for
gliders.


The Nimbus 4 has a mechanism whereby full rudder operates
a small portion of aileron at the tip so as to counteract
the adverse yaw at the expense of a reduced roll rate.

I have heard that some big jets, perhaps 737 and such,
use spoilers
for additional roll authority as well.
And the U-2 was rumored to have twisting trailing edge
landing gear,
so landing in a crosswind in a crab was fine.

Don't know about the U2 but I believe the B52 incorporates
both of these features, it has no ailerons at all,
entirely relying on differential spoilers for roll
control. Allows a lighter wing with less torsional
stiffness at the expense of awful handling 'feel' and
all of the wheels steer to allow crabbing on the ground,
both for taxying through small (small is a relative
term when you've got a 56m wingspan) gaps and landing
in cross winds.