why trim tab on right side and not left instead ?

[Doug Royer [N6AAW]]

P-Factor ?

In article <327AC7...@CNET.com>, Jay Krish <j...@CNET.com> writes:
> Hi folks,
>
> Most light GA planes have trim tabs only on one side of the elevator
> and this always seems to be the "right hand side" ..
>
> why the "right" side reasoning ? .. why not the left side ?
>
> anyone know ??
>
> there's got be an aerodynamic reason for this ...
>
> - j

--
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[Jay Krish]

[Glynne Rees]

In article <1996Nov...@Eng.Sun.COM>, "Doug Royer [N6AAW]"
<do...@Eng.Sun.COM> writes

>P-Factor ?
>
>In article <327AC7...@CNET.com>, Jay Krish <j...@CNET.com> writes:

Here is a wild guess....

The slip stream effect from a clockwise rotating prop hits the left side
of the fin/rudder. Maybe the elevator surface on the right is more
sheltered from the slipstream by the fin/rudder.

--
Glynne

[Jeffrey M. Matthews]

In article <327AC7...@CNET.com>, Jay Krish <j...@CNET.com> wrote:
>Hi folks,
>
>Most light GA planes have trim tabs only on one side of the elevator
>and this always seems to be the "right hand side" ..
>
>why the "right" side reasoning ? .. why not the left side ?
>
>anyone know ??
>
>there's got be an aerodynamic reason for this ...
>

Hmmm....Our Scout has a trim tab on the left elevator, as did its Champish
ancestors. My glider originally had trim tabs on both sides, and to con-
vert it to civil regisration the right tab was eliminated. Seems I could
see the Luscombe's trim tab from the cockpit, so it must have been on the
left too.

I suspect that the placement of the trim tab results from convenience in
running the cables around obstructions rather than from aerodynamics.

Jeff Matthews

[ifly]

jmma...@apgea.army.mil (Jeffrey M. Matthews) wrote:
>In article <327AC7...@CNET.com>, Jay Krish <j...@CNET.com> wrote:
>>Hi folks,
>>
>>Most light GA planes have trim tabs only on one side of the elevator
>>and this always seems to be the "right hand side" ..
>>
>>why the "right" side reasoning ? .. why not the left side ?
>>
>>anyone know ??
>>
>>there's got be an aerodynamic reason for this ...

My Luscombe has it on the left, as well as the Hatz I`m building. I think
most Airknockers have it on the left, the Stinson L5 cetainly did, I`m
not sure about the others, the Bell P39, So it`s across a large range of
performance, and not limited to Rag bags. You could be right. If
anything, it would have to do with prop slipstream, or convienience of
installation, or maybe it`s just "eeny meeny miney moe" (The politically
correct version of course!)
Looked it up in a couple of design books I have, and no mention was made.

Jeff Morris

[Jonathan Birge]

My guess is that it tends to balance out the many left turning
tendancies of the plane (P-factor, prop gyro, spiral prop wash and prop
torque). Of course, this doesn't balance all of it and so there are
usually immovable vertical tabs (correct word?) or yaw trim tabs to
account for the rest.

-Jonathan

Jay Krish wrote:
>
> Hi folks,
>
> Most light GA planes have trim tabs only on one side of the elevator
> and this always seems to be the "right hand side" ..
>
> why the "right" side reasoning ? .. why not the left side ?
>
> anyone know ??
>
> there's got be an aerodynamic reason for this ...
>

> - j

[John R. Johnson]

My airplane has the elevator trim tab on the left hand half of
the elevator.

John

[Curtis Wheeler]

John R. Johnson wrote:
>
> My airplane has the elevator trim tab on the left hand half of
> the elevator.

Your plane was obviously designed by democrats.

--

Curtis

[John R. Johnson]

No wonder it is so good! :-) Republican airplanes splash mud around
and then go over on their backs!

John

[Sylvain Louboutin]

ronk...@earthlink.net (Ron Kelley) writes:

>Jay Krish <j...@CNET.com> wrote:
>>Most light GA planes have trim tabs only on one side of the elevator
>>and this always seems to be the "right hand side" ..
>>why the "right" side reasoning ? .. why not the left side ?

>My guess is that (1) it's not necessary to have trim tabs on both
>sides (one is plenty effective), and (2) it's cheaper.

note that the Aerospatiale/Socata Rallye aircraft (a low wing side by
side four seaters; comes in various flavors, from 100hp to 234hp but
the general layout remains the same it seems except that the bigger
ones have a yoke instead of a stick) have the trim conveniently located
on the left side (this aicraft also has the throttle on the left side,
one for each seat, which is quite neat if you are right handed);

--
%% Sylvain....@dsg.cs.tcd.ie http://www.dsg.cs.tcd.ie/~sloubtin/
%% Distributed Systems Group, (O'Reilly Institute, room F.35)
%% Department of Computer Science, phone: (+353-88) 527790
%% Trinity College, Dublin 2, -Ireland- fax: (+353-1) 6772204

[Harg Tholan]

On 6 Nov 1996 01:00:10 GMT, slou...@cs.tcd.ie (Sylvain Louboutin)
wrote:

>>>Most light GA planes have trim tabs only on one side of the elevator
>>>and this always seems to be the "right hand side" ..
>>>why the "right" side reasoning ? .. why not the left side ?
>>My guess is that (1) it's not necessary to have trim tabs on both
>>sides (one is plenty effective), and (2) it's cheaper.
>
>note that the Aerospatiale/Socata Rallye aircraft (a low wing side by
>side four seaters; comes in various flavors, from 100hp to 234hp but
>the general layout remains the same it seems except that the bigger
>ones have a yoke instead of a stick) have the trim conveniently located
>on the left side (this aicraft also has the throttle on the left side,
>one for each seat, which is quite neat if you are right handed);

Now, are we discussing where the trim controls are placed, or
the actual trim tab on the elevator? I've never seen controls placed
on the left side, though that's not to say they don't exist.
Generally, I've also the trim tab on the right side of the elevator
(in relation to the vert. stabilizer). Though, my instructor's Twin
Comanche has. I believe, a trim tab running the entire length of the
stabilator. I'll lay money that the primary reasoning behind the
position of the tab itself probably lies in which side it will be
easier to route the cables to.

---
Harg Tholan
tho...@telepath.com

"We did Nebraska in 7-1/2 minutes today.
I think that's the best way to do Nebraska."
- SR-71 Pilot

[Steve Pugh]

In article <32802e17...@snews.zippo.com>
tho...@telepath.com (Harg Tholan) wrote:

>>>>Most light GA planes have trim tabs only on one side of the elevator
>>>>and this always seems to be the "right hand side" ..
>>>>why the "right" side reasoning ? .. why not the left side ?
>>>My guess is that (1) it's not necessary to have trim tabs on both
>>>sides (one is plenty effective), and (2) it's cheaper.

> Now, are we discussing where the trim controls are placed, or

> the actual trim tab on the elevator? I've never seen controls placed
> on the left side, though that's not to say they don't exist.
> Generally, I've also the trim tab on the right side of the elevator
> (in relation to the vert. stabilizer). Though, my instructor's Twin
> Comanche has. I believe, a trim tab running the entire length of the
> stabilator. I'll lay money that the primary reasoning behind the
> position of the tab itself probably lies in which side it will be
> easier to route the cables to.

Just guessing, but wouldn't the right side of the elevator be preferable just because any drag it
induced would play the role of a wee-little right rudder, and counter torque, P-factor, all that fun "right
rudder" stuff?

[Harg Tholan]

On 6 Nov 1996 19:03:10 GMT, st...@foundation-i.com (Steve Pugh) wrote:

>Just guessing, but wouldn't the right side of the elevator be preferable just because any drag it
>induced would play the role of a wee-little right rudder, and counter torque, P-factor, all that fun "right
>rudder" stuff?

You would think so, but hey, these are airplanes, who needs
aerodynamics? 8-D Actually, wouldn't the tab still cause a left-turn
tendency when trimmed nose-down (on an airplane with the tab on the
right side)?

[Andrew Boyd]

John R. Johnson <jo...@siu.edu> wrote:

>My airplane has the elevator trim tab on the left hand half of
>the elevator.

Hiya john. So does my maule.

--
#include <std.disclaimer>

[Steve Pugh]

In article <32821043...@snews.zippo.com>
tho...@telepath.com (Harg Tholan) wrote:

>>Just guessing, but wouldn't the right side of the elevator be preferable just because any drag it
>>induced would play the role of a wee-little right rudder, and counter torque, P-factor, all that fun "right
>>rudder" stuff?
>
> You would think so, but hey, these are airplanes, who needs
> aerodynamics? 8-D Actually, wouldn't the tab still cause a left-turn
> tendency when trimmed nose-down (on an airplane with the tab on the
> right side)?

Hmmm...ya mean like a little more surface on the right side, causing a little more lift? Wacky, kooky,
but it just might work...

Let's just say that when I build my Pietenpol, I'll find out why the tab goes where it goes. (Where'd I
put those plans? It *did* have a tab, didn't it? Bah, who knows?)

Cheers,

-Steve

[ben]

On 8 Nov 1996 02:00:42 GMT, st...@foundation-i.com (Steve Pugh) wrote:

>In article <32821043...@snews.zippo.com>
>tho...@telepath.com (Harg Tholan) wrote:
>

Steve:

The P-FACTOR idea sounds okay... Honestly, I don't think it matters a hoot.

ESPECIALLY on a Pietenpol. I've not seen a Piet with a trim tab. You could add
one, but why bother with the added mechanical headaches. It isn't REALLY
needed. You would probably be better off putting a bungee-trim system in, like
the Tailwind has.

Oh - and on the discussion why left or right - don't forget that V-TAIL Bonanzas
have it on both... And some aircraft without a split-elevator have it in the
middle.