Flight Training - August 2014 - 37

is created when the ailerons are deflected. The down aileron
increases the airfoil camber, thereby increasing lift. Increased lift
is always accompanied by increased drag; that's just the way the
vectors work. Because the ailerons are down on only one wing
(outboard), that wing has more lift, so it moves vertically up, rolling the airplane into a bank, which in turn increases drag. The
inboard aileron is up, so that wing has less lift and less drag. The
increased drag holds the outside wing back, causing the airplane
to yaw to the outside of a turn while banking. Think of it in terms
of bank left, yaw right, or vice versa. Knowing this, it makes thus
makes sense that the drag on the two wings is imbalanced only
while the ailerons are deflected and disappears when the bank is
stabilized. At that point, all forces are balanced and aileron and
rudder do not need to be deflected.
Adverse yaw is cancelled out by creating positive yaw via rud- STEP 1 calls for the pilot to simultaneously bank in the direction of the turn
while also applying rudder in that same direction.
der in the direction of the turn. Left turn, left rudder, and so on
DEFINE A GOOD TURN. A good place to start defining "good turn"
would be to simply say, "Throughout the entire turn, roll-in to
roll-out, the ball stays in the middle." That's a pretty basic statement. So, why aren't all turns done that way?
Modern aircraft have been carefully designed to minimize
some of the effects we've been discussing. The adverse yaw is
there, but it is so small that it's easy to overlook. More damaging, it's easy to just ignore the rudder altogether when making
normal turns that require minor aileron displacements.
A logical question would be, "Is the ball moving when these
feet-on-the-floor turns are being made?" Yes, it is. It's impossible
for it not to move to one degree or another, depending on the
airplane. Such nuances are easily ignored, but nuances are what
spell the difference between doing it right and doing it more or
less right.
Ignoring the rudder during turns leads to a general complaSTEP 2 is establishing the turn. Here the controls are neutral.
cency in which aileron movements and rudder movements aren't
terminally linked together in the pilot's brain. So, when extreme
situations happen, such as battling really nasty turbulence/
wind conditions on short final where the trusty old Cessna 172
requires all the aileron it has in both directions, the feet aren't
subconsciously part of the equation. It's in this kind of situation
in any airplane-making rapid, big aileron deflections-that even
the most modern aircraft with state-of-the-art aileron design
will be sliding the ball back and forth. The result will be that the
nose will also be yawing right and left at a time when we'd really
like to have it straight in front of us for a decent touchdown.

MODERN AIRCRAFT HAVE BEEN CAREFULLY
DESIGNED TO MINIMIZE SOME OF THE
EFFECTS OF ADVERSE YAW. IT IS THERE, BUT
IT IS SO SMALL IT'S EASY TO OVERLOOK.

STEP 3 is the rollout, which is done with aileron and rudder back toward level
flight, or right in this case.

AUGUST 2014 FLIGHT TRAINING

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Flight Training - August 2014

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