Page 27 - March19

If this sounds familiar to you, you are not mistaken.
I included a reference to the need for rudder trim
adjustment in a previous article discussing Yaw
Dampers. However, I believe this is an important topic
that deserves another look. I still see a lot of King Air
pilots accepting one-wing-low as normal. Folks, we can
be better than that! KA
King Air expert Tom Clements has been flying and
instructing in King Airs for over 46 years, and is the
author of “The King Air Book.” He is a Gold Seal CFI and
has over 23,000 total hours with more than 15,000 in
King Airs. For information on ordering his book, contact
Tom direct at twcaz@msn.com. Tom is actively mentoring
the instructors at King Air Academy in Phoenix.
If you have a question you’d like Tom to answer, please
send it to Editor Kim Blonigen at editor@blonigen.net.
with pilots who treat rudder trim and aileron trim the
same – rarely if ever touching either one – is because
the result is uncoordinated flight. Please work at being
more aware of coordination. “But I am aware! I keep
the ball pretty darn well centered!”
Yes, I am sure the ball is “pretty darn well centered”
most of the time, as it should be. Give yourself a pat on
the back; you’re doing good thus far. However, the amount
the ball is out of the center – or the slip-skid bar is not
aligned with the bank index – in level cruise flight is
so small as to be almost unnoticeable even though the
wings are obviously not level. Holding a constant heading
with level wings and equal engine power, by definition,
means that the airplane is perfectly coordinated. It is
my belief that comparing wing-tip-to-horizon alignment
– in almost all cases – is a more accurate way of gauging
the true state of coordination than the ball.
You will come to find that adding some right rudder
trim will always be required as you climb after takeoff,
unless you dialed in a little while setting trim wheel
positions before takeoff. A small left rudder trim tweak
will invariably be required as you level off and accelerate
into cruise. If speed picks up in the descent, you’ll need
a dab of more left rudder trim. Extension of flaps and
gear? Because other things are changing so quickly
now – airspeed, power, probably altitude – there usually
won’t be enough time to make the
wing-low evaluation of trim. But be
alert to the ball. Trim as needed.
As you all know, trim merely
lets us reduce control forces.
Everything I am saying about
rudder trim could be accomplished
by pushing the correct rudder
pedal. Of course, there are times
when forceful and timely rudder
pedal input is necessary … like
when an engine experiences a
loss of power! When hand-flying
without the Yaw Damp engaged,
yes indeed, it may be easier to just
press a little harder on one pedal
than spending time adjusting the
trim. However, since we almost
always have Yaw Damp engaged
– and, 90 percent of the time,
the autopilot as well – the rudder
pedals resist our attempts to move
them due to the Yaw Damper doing
its thing. Rather than overpower
the rudder servo or get a leg cramp
because of the continuous force
being applied, I suggest adjustment
of rudder trim is much preferred
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MARCH 2019 MARCH 2019 KING AIR MAGAZINE •
KING AIR MAGAZINE •
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