With a swept wing aircraft (specifically a MiG-25 I am modelling) where is the root chord taken from to calculate the location of CG? Is it the root chord of the wing (where it attaches to the fuselage) or a projected line extended from the the leading / trailing edge to the centreline of the fuselage?
For CG calculations on swept wing aircraft you don't use root cord, you use mean aerodynamic chord or MAC. To calculate the MAC:
- Identify the center of gravity location, in inches from the datum.
- Identify the leading edge of the MAC (LEMAC), in inches from the datum.
- Subtract LEMAC from the CG location.
- Divide the difference by the length of the MAC.
- Convert the result in decimals to a percentage by multiplying by 100.