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Weight & Balance (W&B) converting MAC to CG (in)

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Posts: 73
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Group I am purchasing a 1947 108-2 and will bringing her to Kansas in the next few weeks. In anticipation of flying her to her new home and to also acquaint myself with the W&B of the aircraft I have been running some sample loading configurations. ALSO - I have purchased the for the iPad that I plan to use to in the aircraft. In addition to assisting during navigation the app also has a W&B tool that appears to be helpful. With this said though, the app needs five data points for three "Forward CG Limit Points" and Two "Aft CG Limit Points" but the app specifically does not accept % of MAC but requires "CG (in)" for the data points.

I have downloaded the spreadsheet which works well, but it does not show the "CG (in)" data.

So do any of you have a spreadsheet that shows or lists all of the Forward and Aft CG (in) limit points? Or better yet, do any of you already have the Foreflight W&B for a 108-2 that you can share with me (us)?

Thank you.
Bret C
Neodesha, KS

Posted : 30/08/2015 8:22 pm
Posts: 57
Trusted Member

I know this might be a bit late, based on the date of your posting. But, try the TCDS A-767 that you can get off of It has all of the pertinent C.G. information for you. In the 108-1 Operators Manual, there is a conversion process to change % MAC to C.G. Just an input a few years later.


Posted : 16/05/2017 12:28 am
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Charles L Gruby Gruby
Posts: 72
Trusted Member

Well let's see if we can make this simple.
The wing chord is 4'9" or 48" + 9" = 57"
To find where the cg limits are in inches, simply convert the percentage to decimal and multiply times the chord width. In fact my book on the 108-2 lists the fwd limit as 10.62" (as measured from the wing LE) and an aft limit of 21.33".

Univair sells the ops manual and the maintenance manual.

I've owned a couple of -2"s and one -3. Let me know if I can help.

Posted : 16/05/2017 3:12 am
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Posts: 57
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Owners Ops book shows a good example of the envelope for the stinson. Remember, the bottom line is your empty weight. Both forward and aft, which is the number you get from your current wt and bal document. Along with the CG points. Work both Utility and Normal in your envelope as separate entries. This aircraft has many input points. It works great in Foreflight and any other wt. & bal. program you have. I have tried to attach an example. Hope it works.

Posted : 02/12/2017 10:55 pm
Bret and Bret reacted