| Cell A1 |
2 |
3 |
4 |
5 |
6 |
7 |
| Spar Load Calculation | ||||||
| Span in inches | 70.41 | S | ||||
| Total Spar Depth, inches | 0.96875 | SD | =B3/2 | 70 | HS | HS =S/2 |
| Total Spar Width, inches | 0.375 | SW | ||||
| Thickness of Spar Cap | 0.125 | CT | =B7/2*B8 | 210 | HL | HL=W/2*L |
| Weight of Airplane in Pounds | 6 | W | ||||
| Design Load Factor | 6 | L | =D4*(D6/2) | 250 | RS | RS=HS*(HL/2) |
| =B4-(2*B6) | 290 | J | J=SD-(2*CT) | |||
| Spar Material Factor | 9000 | |||||
| Enter 9000 for Spruce, | =(B5*(B4^3-D10^3)/12) | 330 | C | C=(SW*(SD^3-J^3)/12) | ||
| 2500 for light balsa, | ||||||
| 4000 for very hard balsa | =B4/2 | 370 | E | E=SD/2 | ||
| =D8/(D12/D14) | 390 | Z | Z=RS/(C/E) | |||
| Design is | =D18 | Percent | =B11/D16*100 | K | K=9000/Z*100 | |
| of required Strength |
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