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further lessons from an aerobatic instructor that I was taught that my posterior, sitting in the pilot’s seat, could be a rather good ball substitute. If my body’s weight was evenly distributed so that both butt cheeks carried an equal amount, I knew the ball would be centered. Anytime I felt one side heavier than the other, I was flying uncoordinated and needed to apply more rudder force on the heavier side. Has anyone mentioned this to you? Go up with a pilot friend or instructor and try it yourself. Close your eyes while the other pilot uses the rudder pedals or rudder trim to create some rather gross ball-out-of-center conditions. Now, with your eyes still closed, take the controls and apply rudder force on the side of your heavier cheek until you feel proper left-right weight balance. If you have rudder trim, use it, too. Now open your eyes. Pretty cool, eh? Whether your safety pilot left you in level flight or in a 45-degree bank, you’ll always be able to return to reasonably coordinated flight just by using your now-educated butt.
So let’s say that we’ve just passed through 400 feet HAA (Height Above Airport) following our takeoff in a C90GTx and have engaged the autopilot, which of course brought on the yaw damper, too. After the system follows the FMS command into a turn toward the first departure procedure waypoint and levels out on a steady heading, we notice that the right winglet is a little lower on the horizon than the left one and the slip/skid bar is deflected a little to the right. (The weight is just a tiny bit heavier on our right butt cheek as well.) We could, with some forceful, steady, effort on the right rudder pedal correct this situation, but instead we reach down to the rudder trim wheel and rotate it clockwise – toward the “ball,” toward the low wing – just a tad, maybe one-eighth of one trim unit. Now we continue with our flying duties of traffic scanning, engine gauge monitoring, executing the After Takeoff checklist, etc. A couple of minutes later we note that the ball is still a tiny bit to the right, so we add another eighth of a unit on the rudder trim wheel. Now we see that the wings are level, the slip/skid bar is right under the sky pointer at the top of the PFD, and all is well in our flying world.
As we level out at FL230 – ATC gave us an unrestricted
climb today – we keep climb power while we accelerate
into cruise flight. This gives us time to do some more 26 cockpit monitoring and perhaps even consult the Cruise
Power chart. It slowly dawns on us that now the left wing
is lower than the right and that darn slip/skid bar is now
quite a bit left of center. Our hand goes to the rudder
trim wheel, again turning it toward the skid bar, toward
the lower wing, but not too much ... no more than an
eighth or quarter of a trim unit. Let at least 30 seconds
or so elapse before making another minor adjustment.
Keep doing this until coordination is perfect.
The same minor rudder trimming will be needed during the descent, approach maneuvering and throughout the final descent to landing. Since it’s not as obvious that a very small amount of uncoordination is taking place
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DECEMBER 2023
KING AIR MAGAZINE • 23