limit of trim = limit of travel?

On May 6, 3:36*pm, Bertie the Bunyip wrote:
WingFlaps wrote :





On May 6, 2:19*am, Bertie the Bunyip
wrote:
On May 5, 6:06*am, WingFlaps wrote:

On May 5, 8:48*am, Bertie the Bunyip wrote:

WingFlaps wrote
innews:49efc4b4-8ede-40cd-9ad3-5
:

On May 5, 3:19*am, Bertie the Bunyip wrote:
Stealth Pilot wrote
innews:u8kr141dp0o1e
:

On Fri, 2 May 2008 12:32:28 -0700 (PDT), WingFlaps
wrote:

On May 3, 12:40*am, Stealth Pilot

.au
wrote:
On Wed, 30 Apr 2008 00:12:54 +0000 (UTC), Bertie the
Bunyip wrote:

WingFlaps wrote in
news:ad8fc9c9-57cb-4733-9e97-
:

On Apr 30, 9:37*am, wrote:
On Apr 29, 2:24 pm, WingFlaps
wrote:

I don't follow this. The trim surface operates in
the opposite direction to the trimmed surface and
takes area away from it.

-------------------------------------------------------------





----

^^^
^
Explain
please?

What area stuff?

Cheers

that area stuff. ...which shows a total lack of aerodynamic
understanding.

Still don't know what you're talking about! Most of that
thread has

spooled off my main server now..

He's trolling.

Cheers

He's not, he's right. Deflecting a tab in the oppostie direction
doesn
't
remove area.

It reduces effective area.

No, it doesn´t. The area is stil there. The tab isn´t "hiding"
because

it´s going the other way, it´s just doing something different. it may
be reducing the effectiveness of the surface, but that isn´t the same
thing as reducing the area.

Nope. Effectiveness is proportional to area -from the old lift
equation.

Sure, but the area hasn't changed.


OK, then if the AOA of the stabilator is constant, and the elevator
angle is constant, why does the lift reduce when the trim tab is
deflected in the opposite direction? It's as I said, the effect is as
if the _effective_ area is reduced. You could say that CL is altered
but then it gets more messy as you have to consider different CL's and
areas for each section of the stabilator. It's much simpler to just
subtract the area taken by the trim from the calculation and that will
give a very good first order approximation for longitudinal stability
calculations.

Cheers

On Mon, 5 May 2008 23:54:37 -0700 (PDT), WingFlaps
wrote:

On May 6, 3:36*pm, Bertie the Bunyip wrote:
WingFlaps wrote :



OK, then if the AOA of the stabilator is constant, and the elevator
angle is constant, why does the lift reduce when the trim tab is
deflected in the opposite direction?

because the elevator angle isnt bloody constant. what is constant is
the stick force which you maintain at the same pressure by
unconsciously moving the stick as you change the trim tab position.




It's as I said, the effect is as
if the _effective_ area is reduced.

no it bloody isnt. the area remains the same the lift force is what
varies and guess what, that's why the tailfeathers have the hinges in
the middle.

You could say that CL is altered
but then it gets more messy as you have to consider different CL's and
areas for each section of the stabilator. It's much simpler to just
subtract the area taken by the trim from the calculation and that will
give a very good first order approximation for longitudinal stability
calculations.


you have basically started out with a faulty understanding and for the
last 100 posts have misinterpreted everything written because you keep
relating the information to the original faulty premise.

Stealth Pilot

On May 7, 12:56*am, Stealth Pilot
wrote:
On Mon, 5 May 2008 23:54:37 -0700 (PDT), WingFlaps

wrote:
On May 6, 3:36*pm, Bertie the Bunyip wrote:
WingFlaps wrote :

OK, then if the AOA of the stabilator is constant, and the elevator
angle is constant, why does the lift reduce when the trim tab is
deflected in the opposite direction?

because the elevator angle isnt bloody constant. what is constant is
the stick force which you maintain at the same pressure by
unconsciously moving the stick as you change the trim tab position.

It's as I said, the effect is as
if the _effective_ area is reduced.

no it bloody isnt. the area remains the same the lift force is what
varies and guess what, that's why the tailfeathers have the hinges in
the middle.

You could say that CL is altered
but then it gets more messy as you have to consider different CL's and
areas for each section of the stabilator. It's much simpler to just
subtract the area taken by the trim from the calculation and that will
give a very good first order approximation for longitudinal stability
calculations.

you have basically started out with a faulty understanding and for the
last 100 posts have misinterpreted everything written because you keep
relating the information to the original faulty premise.


Nope. I understand it perfectly. As defined in any good book on
aeronautical design, stabilator effectiveness is _defined_ by the
horizontal tail volume coefficient which is the product of tail moment
and area divided by the wing area and it's mean chord.

From the style of you reply I can see you will have a hard time
understanding this this it really is correct -look it up.

Cheers

WingFlaps wrote in
:

On May 7, 12:56*am, Stealth Pilot
wrote:
On Mon, 5 May 2008 23:54:37 -0700 (PDT), WingFlaps

wrote:
On May 6, 3:36*pm, Bertie the Bunyip wrote:
WingFlaps wrote
innews:4c947801-0112-4fa1-92e7-09
:

OK, then if the AOA of the stabilator is constant, and the elevator
angle is constant, why does the lift reduce when the trim tab is
deflected in the opposite direction?

because the elevator angle isnt bloody constant. what is constant is
the stick force which you maintain at the same pressure by
unconsciously moving the stick as you change the trim tab position.

It's as I said, the effect is as
if the _effective_ area is reduced.

no it bloody isnt. the area remains the same the lift force is what
varies and guess what, that's why the tailfeathers have the hinges in
the middle.

You could say that CL is altered
but then it gets more messy as you have to consider different CL's
and areas for each section of the stabilator. It's much simpler to
just subtract the area taken by the trim from the calculation and
that will give a very good first order approximation for
longitudinal stability calculations.

you have basically started out with a faulty understanding and for
the last 100 posts have misinterpreted everything written because you
keep relating the information to the original faulty premise.


Nope. I understand it perfectly. As defined in any good book on
aeronautical design, stabilator effectiveness is _defined_ by the
horizontal tail volume coefficient which is the product of tail moment
and area divided by the wing area and it's mean chord.

From the style of you reply I can see you will have a hard time
understanding this this it really is correct -look it up.


I understand what you are saying perfectly. You might think it's a handy
way to look at the problem, but it's simpoistic and incorrect..
End of story.


Bertie

On Tue, 6 May 2008 07:16:07 -0700 (PDT), WingFlaps
wrote:

On May 7, 12:56*am, Stealth Pilot
wrote:
On Mon, 5 May 2008 23:54:37 -0700 (PDT), WingFlaps

wrote:
On May 6, 3:36*pm, Bertie the Bunyip wrote:
WingFlaps wrote :

OK, then if the AOA of the stabilator is constant, and the elevator
angle is constant, why does the lift reduce when the trim tab is
deflected in the opposite direction?

because the elevator angle isnt bloody constant. what is constant is
the stick force which you maintain at the same pressure by
unconsciously moving the stick as you change the trim tab position.

It's as I said, the effect is as
if the _effective_ area is reduced.

no it bloody isnt. the area remains the same the lift force is what
varies and guess what, that's why the tailfeathers have the hinges in
the middle.

You could say that CL is altered
but then it gets more messy as you have to consider different CL's and
areas for each section of the stabilator. It's much simpler to just
subtract the area taken by the trim from the calculation and that will
give a very good first order approximation for longitudinal stability
calculations.

you have basically started out with a faulty understanding and for the
last 100 posts have misinterpreted everything written because you keep
relating the information to the original faulty premise.


Nope. I understand it perfectly. As defined in any good book on
aeronautical design, stabilator effectiveness is _defined_ by the
horizontal tail volume coefficient which is the product of tail moment
and area divided by the wing area and it's mean chord.

From the style of you reply I can see you will have a hard time
understanding this this it really is correct -look it up.

Cheers

no I'm afraid that it is you who do not understand it.
you take a rule of thumb approximation and then try to apply it as a
hard and fast aerodynamic concept.

brother have you got it wrong.
Stealth Pilot

WingFlaps wrote in
:

On May 6, 3:36*pm, Bertie the Bunyip wrote:
WingFlaps wrote
innews:4c947801-0112-4fa1-92e7-09f00
:





On May 6, 2:19*am, Bertie the Bunyip
wrote:
On May 5, 6:06*am, WingFlaps wrote:

On May 5, 8:48*am, Bertie the Bunyip wrote:

WingFlaps wrote
innews:49efc4b4-8ede-40cd-9ad3-5
:

On May 5, 3:19*am, Bertie the Bunyip wrote:
Stealth Pilot wrote
innews:u8kr141dp0o1e
:

On Fri, 2 May 2008 12:32:28 -0700 (PDT), WingFlaps
wrote:

On May 3, 12:40*am, Stealth Pilot

.au
wrote:
On Wed, 30 Apr 2008 00:12:54 +0000 (UTC), Bertie the
Bunyip wrote:

WingFlaps wrote in
news:ad8fc9c9-57cb-4733-9e97-
:

On Apr 30, 9:37*am,
wrote:
On Apr 29, 2:24 pm, WingFlaps
wrote:

I don't follow this. The trim surface operates in
the opposite direction to the trimmed surface and
takes area away from it.

-------------------------------------------------------------





----

^^^
^
Explain
please?

What area stuff?

Cheers

that area stuff. ...which shows a total lack of
aerodynamic understanding.

Still don't know what you're talking about! Most of that
thread has

spooled off my main server now..

He's trolling.

Cheers

He's not, he's right. Deflecting a tab in the oppostie
direction doesn
't
remove area.

It reduces effective area.

No, it doesn´t. The area is stil there. The tab isn´t "hiding"
because

it´s going the other way, it´s just doing something different. it
m
ay
be reducing the effectiveness of the surface, but that isn´t the
same

thing as reducing the area.

Nope. Effectiveness is proportional to area -from the old lift
equation.

Sure, but the area hasn't changed.


OK, then if the AOA of the stabilator is constant, and the elevator
angle is constant, why does the lift reduce when the trim tab is
deflected in the opposite direction? It's as I said, the effect is as
if the _effective_ area is reduced. You could say that CL is altered
but then it gets more messy as you have to consider different CL's and
areas for each section of the stabilator. It's much simpler to just
subtract the area taken by the trim from the calculation and that will
give a very good first order approximation for longitudinal stability
calculations.


It's not correct to do it that way, and if you're actuasly talking about
calculations, then you're going to be way off the mark.