How to calculate Index from %MAC Values
 

How would I go about to calculate index from only %MAC values?


For example a Bombardier Global 7500 only operates in %MAC.


How would I translate that into Index values?


LEMAC: 670.560

MACLEN: 179.040


Is there a calculation for this?

Hi.
​​​​​​Index and MAC percent are two different things. MAC percent is a physical place. You can touch it.

Index is a convenient, dimensionless moment (usually scaled and offset so always positive)

Index = (((H_arm - ReferenceStation)* Mass of item) / ScalingConstant) +offset.

Substitute H_arm as percent MAC and rearrange formula.

H_arm= LEMAC+MAC*PercentMAC

Hope this helps.