Page 106 - EAA78.Newsletter.Archives.(February.2017-July.2021)
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CHAPTER CHATTER, EAA Chapter 78 9
called tail-down force. weight equal each other. But that's not exactly
the case.
When you look at the diagram below, what you
really see is that weight and tail down
force both need to be balanced out by lift.
Essentially, lift needs to equal weight and tail
down force.
Essentially, your tail is an 'upside down' wing
that generates lift downward. The amount of
lift it needs to maintain depends on two
factors: CG location, and aircraft weight.
How Moment Comes Into Play
The moment calculation is pretty simple: How Does Drag Factor In?
weight x arm = moment (or, force x distance =
torque). So if you have a large amount of force When you create more lift, you create more
at a small distance, it can be balanced out by induced drag as well. So as you can
a small amount of force at a large distance. see, when your CG is forward, you need
You can see it in the diagram below. more tail down force, and more lift. You
generate that extra lift by increasing your
angle of attack, which in turn increases
induced drag.
So Lift And Weight Don't Equal Each Other?
One of the first things you learn as a pilot is
that in level, unaccelerated flight, lift and
