Mechanics of Elevator Trim. In Detail.

"Bertie the Bunyip" <AA@AA.AA> wrote in message
news:g2jm30$98m$1@blackhelicopter.databasix.com...
> Le Chaud Lapin <jaibuduvin@**********> wrote in news:a685e391-2f45-4a75-
> 8058-65e06d3ad43b@z66g2000hsc.************.com:
>
>> On Jun 9, 12:34 am, Tina <tbaker27...@**********> wrote:
>>> Le Chaud Lapin wrote <jaibudu...@**********> wrote:
>>>
>>>
>>>
>>> > Spent 30 minutes at pool yesterday discussing with professional
>>> > metalworkers best way to weld a complex joint for important element of
>>> > prototype of what would be considered a wing.
>>>
>>> > Such things take time, and still, I do not know if it will work.
>>>
>>> > -Le Chaud Lapin-
>>>
>>> to which I would point out that in 2008 most engineers when
>>> considering structures operating at general aviation speeds and
>>> stresses would be thinking of composites and molding complex shapes,
>>> not in terms of bending metal and welded joining.
>>
>> This presumes that you know what the welds are for, which would be
>> difficult, as the welders themselves do not even know at this point.
>>
>
>
> And neither do you.
>
>
> Bertie

And obviously, neither do you.

Little slow over on RAP this morning, Mr. Needsalife?

On Jun 9, 10:25 am, Le Chaud Lapin <jaibudu...@**********> wrote:
> On Jun 9, 12:34 am, Tina <tbaker27...@**********> wrote:
>
>
>
> > Le Chaud Lapin wrote <jaibudu...@**********> wrote:
>
> > > Spent 30 minutes at pool yesterday discussing with professional
> > > metalworkers best way to weld a complex joint for important element of
> > > prototype of what would be considered a wing.
>
> > > Such things take time, and still, I do not know if it will work.
>
> > > -Le Chaud Lapin-
>
> > to which I would point out that in 2008 most engineers when
> > considering structures operating at general aviation speeds and
> > stresses would be thinking of composites and molding complex shapes,
> > not in terms of bending metal and welded joining.
>
> This presumes that you know what the welds are for, which would be
> difficult, as the welders themselves do not even know at this point.
>
> -Le Chaud Lapin-

I would point out

1 there are few structural elements of G A airplanes that cannot be
done very effectively in composites, aned complex shapes lend
themselves to molds, not welds

2 if you were seeking advice without disclosing to those whose advice
you were seeking the parameters of concern, you have shown yourself to
be not very competent as an engineer.

I'm glad you don't work for my husband, but you'd have to be an
excellent fraud to survive in our real world for very long. If you
demonstrate those shortcomings so clearly here I would worry about
your career choice. I know it's your choice and decision, but I hope
you're in a position where mistakes will likely not cause great harm.

Good luck in any event.

On Jun 9, 9:34 am, Le Chaud Lapin <jaibudu...@**********> wrote:

> MSFS was the means by which I discovered the mechanism.
>
> If I had learned in actual aircraft, the question still would have
> been relevant.

I disagree. I've never had a student have trouble understanding trim.
I think this is just something that is confusing for the sim guys. As
such it is more approporiate for a sim group, not a pilot's group.

-Robert, CFII

On Jun 8, 8:54 pm, Le Chaud Lapin <jaibudu...@**********> wrote:

> Spent 30 minutes at pool yesterday discussing with professional
> metalworkers best way to weld a complex joint for important element of
> prototype of what would be considered a wing.

When you go to look for commerical rated pilots to do the test flight
please cross my name off the list.

-Robert, CFII

On Jun 9, 1:06 pm, "Robert M. Gary" <N70...@**********> wrote:
> On Jun 9, 9:34 am, Le Chaud Lapin <jaibudu...@**********> wrote:
>
> > MSFS was the means by which I discovered the mechanism.
>
> > If I had learned in actual aircraft, the question still would have
> > been relevant.
>
> I disagree. I've never had a student have trouble understanding trim.
> I think this is just something that is confusing for the sim guys. As
> such it is more approporiate for a sim group, not a pilot's group.

I never had trouble undestanding it. My ground school instructor said
what was written in the Jeppesen book and moved on.

I think if the book said more about how it worked, there would be no
misunderstanding.

-Le Chaud Lapin-

On Jun 9, 1:19 pm, Gig 601Xl Builder <wrgiac...@REMOVE**********>
wrote:
> Le Chaud Lapin wrote:
> > MSFS was the means by which I discovered the mechanism.
>
> > If I had learned in actual aircraft, the question still would have
> > been relevant.
>
> > -Le Chaud Lapin-
>
> You never learned of trim until MSFS and you are going to design an
> airplane. Fabulous!

Is it really necessary to understand the particular way it was done in
C172 to achieve the same result?

The same thing could be achieved using more electronics, less
mechanics, and the controls might be entirely different.

-Le Chaud Lapin-

On Jun 10, 4:34 am, Le Chaud Lapin <jaibudu...@**********> wrote:
> On Jun 9, 10:58 am, "Robert M. Gary" <N70...@**********> wrote:
>
> > On Jun 8, 10:20 am, Le Chaud Lapin <jaibudu...@**********> wrote:
>
> > > On Jun 8, 11:07 am, "Robert M. Gary" <N70...@**********> wrote:
> > > For sake of those of us who only own MSFS, let's say a C172.
>
> > What does MSFS have to do with anything. This is a pilot news group,
> > not sim. There are sim groups out there that would be more appropriate
> > for your question.
>
> MSFS was the means by which I discovered the mechanism.
>
> If I had learned in actual aircraft, the question still would have
> been relevant.
>

And now all is clear.

Cheers

On Jun 9, 3:30 pm, Gig 601Xl Builder <wrgiac...@REMOVE**********>
wrote:
> Not knowing about trim by someone who thinks they are going to design an
> airplane is like someone who wants to be an electrician and doesn't
> understand the difference in AC and DC.
>
> It's just another example that you have no business trying to design an
> aircraft.

This is a false analogy.

It depends on what is meant by "knowing about trim". The purpose of
trim is clear, and the objective of trim can be achieved in many
ways.

It is not necessary to know all the ways that the objective of trim
can be achieved in order to implement just one mechanism that achieves
the objective.

-Le Chaud Lapin-

On Jun 9, 11:31 am, Le Chaud Lapin <jaibudu...@**********> wrote:
> On Jun 9, 1:06 pm, "Robert M. Gary" <N70...@**********> wrote:

> I think if the book said more about how it worked, there would be no
> misunderstanding.

I think if you walked up to an actual airplane there would be no
misunderstanding.

-Robert

On Jun 9, 6:19 pm, "Robert M. Gary" <N70...@**********> wrote:
> On Jun 9, 11:31 am, Le Chaud Lapin <jaibudu...@**********> wrote:
>
> > On Jun 9, 1:06 pm, "Robert M. Gary" <N70...@**********> wrote:
> > I think if the book said more about how it worked, there would be no
> > misunderstanding.
>
> I think if you walked up to an actual airplane there would be no
> misunderstanding.

My first experience with trim control was neither with a book or a
plane, but with the instructor. I think there are a lot of things
that students are assumed to know that they do not, which can be
frustrating, as there is no difficult in the concepts, but the
ommission of facts, which hurts more than helps. It is the
instructor's choice to determine how deep s/he should delve into the
mechanics of flight.

One instructor might say, "Move trim wheel up or down to relieve
pressure on yoke."

Another might say, "Trim wheel is connected to a trim tab on elevator,
often located on one side of elevator only, and air moving across
elevator results in aerodynamic force vector on tab that acts on
elevator to position elevator so that point of equilibrium is reached,
and such force being sufficient that you no longer need the yoke to
position the elevator. As you can imagine, speed and orientation of
aircraft will have some effect on force...and therefore position of
elevator. Also, if only one tab, force applies asymetrically to
aircraft...etc."

Both these explanations are true, but one of them eliminates the need
for $30 product (or $30,000 aircraft) to know what is going on.

-Le Chaud Lapin-