Volumes have been written on Weight and Balance calculations. You can use your favorite method.
Or (preferred) use the interactive Panther S, and Panther LS Excel spread sheets found in the Panther Cave W&B Folder Link.
Using Panther Interactive W&B Spreadsheets
1.Always download and save the spread sheets, then open it and “save as” and rename the file something relevant, but not the original name (suggest N number and your name). This leaves original sheet on your computer in case you somehow corrupt the “working” sheet. You can also do this several times to save different W&B scenarios.
2.Fill out information cell across top. In equipment area note things like wheel pants, if painted, and battery location/type and weight.
3.On the bottom of sheet find Original weight-empty CG and open it.
4.Fill in cells B7-9 and C7-9.
5.Fill in cells C25-27 and note the pilot weight and arm.
6.Using tab on bottom open sheet W&B main.
Note: Cells C10 and F10 are automatically filled in with the calculated value from previous page. If these cells are disturbed you will need to manually enter the values from previous page (cells C10 and F10) you can also use to manually enter empty weight and CG if you have these from logs, but do not have original main wheel weights handy.
7.In cell B/C12 Enter in pilot Arm and Weight from cell B/C29 previous page.
8.Use the other orange cells to calculate Various CG Conditions observing effects on CG range and Gross weight.
9.Use other cells across bottom to calculate most forward and aft CG conditions
Note: Please email a copy of this spread sheet, with at least first page filled out, to Support@flywithspa.com. We are keeping these on file to help track builder trends, and various combinations etc. for future reference.
Making additions or Deletions Later
You can use cells A13-18 and C13-18 to update CG after Modifications, or changes without reweighing the aircraft. To add an item simply enter arm from datum, and weight. The new empty weight, and empty CG will show in Cells C19 and F19. You may need to manually enter these on next page.
To remove an item enter inch’s from datum, and use a negative (–) weight.
The sheet will do multiple changes. We recommend doing each addition or subtraction and recording the Empty weight and Empty CG for each change in the aircraft logs for future reference. This function is also handy for playing what if… like moving your battery, or even seeing how a different engine may affect the CG.
SPA is building a data base of FWF package Weights and Arms to assist in this.
