Page 105 - EAA78.Newsletter.Archives.(February.2017-July.2021)

CHAPTER CHATTER, EAA Chapter 78 8

Why Does CG Location Affect Your Airplane's
Performance?

When you load up your plane for a flight, you

need to make sure you're within your center of
gravity (CG) limits. And you probably know

that when your CG moves forward or aft, it

affects your airplane's performance. But why?
Lift acts upward from your wing, at a point
Forward vs. Aft CG called the center of lift. And the center of lift is

always aft of your CG (as long as you are
The relationship between your aircraft's
within your aircraft's CG limits).
performance and CG location is simple: by

moving your CG forward and aft, you change If you look at the diagram below, you can
the amount of tail down force and lift you clearly see that if you didn't have a tail creating

need for stable flight. its own force, your airplane would nose
straight down because of the moment created

between the CG and center of lift (this can
also be called torque).

When you create more lift, you create more

induced drag, and your performance goes

down. But why are lift and CG location

related?

CG: Your Airplane's Balancing Act Your elevator (or stabilator) balances out the

moment by creating its own force,
Your airplane balances on its CG, and that

location is where the downward force acts on
your aircraft.