L23 weight and balance

[Tony Verhulst]

I understand how to determine the CG from the charts in the manual. But,
I would like to do it the traditional way - you know, moment = arm *
weight....

The manual does not provide the arm numbers for the various positions,
not does it tell you the numeric CG range. A bit odd, I think, but there
you are.

I would appreciate any one having that data to kindly point me to it.

Thanks and regards,

Tony V.

[BTIZ]

Tony.. I have referenced my L-23S manual and the USAF Flight Test Center
"SPIN TEST" report on the L-23.

The reference datum is 93.6 in aft of the sailplane nose (paragraph 6.3)
This also correlates to the leading edge of Rib #1, Table in Para 6.6, arm
for reference for installing instruments defines "Arm from the reference
plane (rib #1 in ft.", this becomes the "zero" line). Front instrument panel
is -5.82ft and rear instrument panel is -1.81ft. Yes.. moment arms are
negative because you are in front of the reference datum.

-5.82 x12 = -69.84 inches (moment arm), -1.82 x12= 21.72 inches
There are rear instrument panel references from -1.79 to -1.87 (something
lost in translation or factory typing error?)

I have made measurements for the seat positions (remember to measure to the
belly button) and determined that the P1(front) is apx -49.9inches and
P2(Rear) is apx -5.8inches (these are personal measurements of the aircraft
and not the manufacturers numbers).

Doing the math from the reference datum to convert %MAC to "inches", I came
up with 23%MAC = 4.397inches aft of datum and 40%MAC is 12.78inches aft of
datum.

For the particular L-23S that this was computed for (empty wt 712# at 21.54
arm (67.4%MAC)
Min pilot weight no ballast was 100#, extreme aft CG limit. Max Solo pilot
wt 225#, extreme forward limit.

Use the W&B factory data to get your numbers.

send me your email, I'll send you a spreadsheet
http://members.cox.net/btiz2 for my address.

BT

"Tony Verhulst" > wrote in message
...
>I understand how to determine the CG from the charts in the manual. But, I
>would like to do it the traditional way - you know, moment = arm *
>weight....
>
> The manual does not provide the arm numbers for the various positions, not
> does it tell you the numeric CG range. A bit odd, I think, but there you
> are.
>
> I would appreciate any one having that data to kindly point me to it.
>
> Thanks and regards,
>
> Tony V.

[Tony Verhulst]

Perfect! Exactly what I need. Thanks!

Tony

[[email protected]]

Go to the FAA site listed below.
The TCDS has all the numbers you are looking for.
The L 23 TCDS is G60EU


http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/8108911a16190383862570e60055cd92/$FILE/G60eu.pdf

[Bob Kuykendall]

If you know the pilot weight and the empty weight and CG location, you
can also determine the pilot arm algebraically. See step 4B about 2/3
of the way down this Dick Schreder article:

http://www.soaridaho.com/Schreder/Schreder/Soaring_Aug_1976_HP-18.html

Thanks, and best regards to all

Bob K.

[BTIZ]

yes it does.. thanx..
BT

> wrote in message
oups.com...
> Go to the FAA site listed below.
> The TCDS has all the numbers you are looking for.
> The L 23 TCDS is G60EU
>
>
> http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/8108911a16190383862570e60055cd92/$FILE/G60eu.pdf
>