Frise ailerons on sailplanes

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.

Competively, it came up against the influx of German
fiberglas gliders that offered in the US market very
high performance gliders.

The design and engineering was done by Max Peterson,
and production was by his company Peterson Sailplane
Corporation in California. That was reported on by
Dick Johnson.
Also, in your 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
in England and who also held the WWII record of bringing
back the most shot up bomber of WWII to base). Tom
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
quite as sensitive and not as quickly roll responsive
as he liked a glider to feel.

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

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 influx of German
fiberglas gliders offered in the US market with very
high performance gliders such as Glasflugel Libelles
and Schleicher Asw-15s.

The design and engineering was done by Max Peterson,
and production was by his company Peterson Sailplane
Corporation in California. That 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 all
moving 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 got
off- airfield landing experience putting
his shotup and then gliding B17 between stonebacked
hedgerows in England;

Tom Hulings eternally holds the WWII record of bringing
back the most shot up bomber of WWII to base with over
2000 holes shot thru his plane. He was on the ball
bearing plant bombing mission August 17 1943 to Schweinfurt
w/ 8th Air Force).

Tom Hulings, a quiet, kind, and cheerful flight loving
gentleman, told me of his flying a J4 Javelin at Bermuda
High
Soaring School (there as a demonstrator). I am witness
to his statements on this glider.

Tom Hulings reported to me at length on our drives
together in his convertible 1970s Chevy between Altanta
and Monroe Ga,
that:
his flying the J4 Javelin 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
quite as sensitive and not as quickly roll responsive
as he liked a glider to feel.

Dick Johnson evaluated the J4 Javelin and wrote his
evaluation.

type this full webaddr below into your browser, click
and read. sorry it wont connect from clicking here
below.

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

Nimbus 3/4 have these spoilers because otherwise the rudder would need to be
substantially larger to provide sufficient yaw authority. Larger rudder =
more drag all the time, little spoiler = a little more drag only during the
beginning of a turn.

--
Bert Willing

ASW20 "TW"


"Andrew Warbrick" a écrit dans le
message de news: ...
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.

If you want to see what can happen when you have no ailerons as all go to
this web site and scroll down to the B-52 crash.

http://www.alexisparkinn.com/aviation_videos.htm


"Andrew Warbrick" wrote in message
...
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.

On Thu, 24 Feb 2005 07:50:23 -0800, "Gary Boggs"
wrote:

If you want to see what can happen when you have no ailerons as all go to
this web site and scroll down to the B-52 crash.

http://www.alexisparkinn.com/aviation_videos.htm

In fact this is going to happen with any aircraft that you stall in a
steep turn close to the ground.


Bye
Andreas

Some people that own Nimbus 3's do not connect the tip spoilers because
they say the effect is negligible. I connect them on mine, but I can't
really say how effective they are - they only come up in the second
half of stick input. I believe the Nimbus 4 arrangement with the tip
spoilers connected to the rudder makes much more sense as I almost
always use much more rudder than aileron when turning into a thermal.

More effective than the tip spoilers is to minimize adverse yaw in the
Nimbeast 3 with easy, patient roll rate - in other words, the faster
and farther I move the ailerons, the quicker I run out rudder - at
thermal speeds.

Once settled into the thermal, it's easy to keep on an even keel, but
it does like to overbank if you let it.

Occasionally, on bad thermal days I can move the ailerons and rudder as
much as I want and the beast just does not want to go where I want it
to!! Swearing seems to help. Other days, it's easy as pie. Probably
more to do with the control system located between the headsets than
anything else.

In any case, a little adverse yaw, overbanking and leg exercises
(rudder dancing) are a small price to pay for the horsepower available
in this glider. Someday I'll learn how to use it's potential - and I
have a lot to learn.

Jim




Bert Willing wrote:
Nimbus 3/4 have these spoilers because otherwise the rudder would
need to be
substantially larger to provide sufficient yaw authority. Larger
rudder =
more drag all the time, little spoiler = a little more drag only
during the
beginning of a turn.

--
Bert Willing

ASW20 "TW"

The use of spoilers as roll control on a sailplane has two major drawbacks
compared to ailerons with adverse yaw. These comments are based on flight
test of a roll spoiler equipped flying wing glider.

First, the relationship of drag to reduction in lift produced by the roll
spoiler changes dramatically with airspeed. There is only one airspeed
where the drag and roll produce a perfectly coordinated turn entry.
(Remember that drag increases with the square of airspeed.)

At airspeeds above the coordinated airspeed, the spoiler will produce too
much drag and the turn entry will skid unless outside rudder is used. This
is called proverse yaw.

At airspeeds below the coordinated airspeed, the roll spoiler will not
produce enough drag and the turn entry will be a slip unless into-the-turn
rudder is applied. (Adverse yaw)

The second major problem with roll spoilers is during a steady turn where
one would normally use top aileron to oppose overbanking. If the pilot
attempts to oppose overbanking with roll spoilers, the drag of the spoiler
will cause the glider to yaw away from the turn. The pilot will then use
into-the-turn rudder to center the yaw string which will cause the
overbanking to resume unless still more top spoiler is used. This will
quickly progress to the point where full top spoiler and full into-the-turn
rudder is applied. This is hardly conducive to a low sink rate.

The lession here is that adverse yaw is actually needed for steady state
turns. In a turn the airspeed and angle of attack varies across the full
span. This results in the outside wing having more drag and lift than the
inside wing causing overbanking. Top aileron restores spanwise symmetry of
lift and drag neatly taming the overbanking.

Adverse yaw is also useful for crosswind landings. Into the wind aileron
produces a down wind yaw that helps align the fuselage with the direction of
flight.

Another way to look at it is that differential spoilers produce a control
response that is not unlike the rudder. If the glider is equipped with both
rudder and roll spoilers it has, in effect, two rudder systems and therefore
lacks true 3-axis controls.

That said, differential spoilers actuated through the rudder control curcuit
can significantly augment a weak rudder.

Bill Daniels

I flew a Javelin J-4 way back in the mid 70's at the old Vacaville
gliderport. Odd little glider, nice big cockpit, lousy drag spoilers,
horrible control feel throught the roll spoilers. OK performance as
long as maneuvering wasn't called for.

It crashed the day after I flew it - stall spin on base to final. I'm
convinced the accident was partially due to the poor glidepath control
and poor roll control - pilot probably got high on final, tried a 360,
then got low and lost it.

Interesting concept for a mid performance low cost glider, and with
conventional ailerons and better spoilers it might have worked - would
have been a nice club-class metal ship for clubs and FBO's.

Kirk

1. Since most current high performance gliders carry their laminar flow
across the aileron gap, the drag penalty of a deflected frise aileron,
compared to the deflected rudder, would be huge.

2. Peterson J-4 Javelin - see later posts for more details.

3. Fox has NICE ailerons, for acro - I always had an irristible urge
to do slow rolls on tow when flying a Fox. Also real nice aileron
snatch at the accelerated stall break. It doesn't fly like a racing
glider, it flies like a little fighter plane.

Kirk

3. Fox has NICE ailerons, for acro - I always had an irristible urge
to do slow rolls on tow when flying a Fox.....

Why didn´t you just do it, it´s fun! ;-)

Markus

PS: The Swift S-1 too has Friese-Ailerons (it has almost the same wing as
the Fox).