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Dutch Rolls
Dutch rolls are a maneuver that I use to teach better roll and yaw coordination. The primary goal of Dutch rolls is to learn
the correct amount of rudder to add in the direction of a roll to keep the nose coordinated as the aircraft enters a turn. I
recommend practicing this maneuver flying away from yourself initially. Start by rolling slowly into a 30-degree left bank.
Uncorrected, the nose will yaw slightly to the right. Add just enough left rudder to keep the nose from displacing away
from center. Once you reach a 30-degree bank angle, roll into a 30-degree bank to the right, and add enough right rudder
to keep the nose from yawing to the left. Notice how much right rudder it takes to counter the adverse yaw caused by
rolling into that right bank. Repeat until you are comfortable with the correct amount of rudder required to coordinate the
turn.
After mastering the maneuver flying away from your self, try it flying towards yourself. It will be frustrating at first, but just
remember that you are adding rudder in the direction of the aileron input. Hopefully this maneuver will help to get your
fingers trained to compensate for adverse yaw and keep those turns coordinated.
Slips
Slips are a maneuver that we’ll use to help prepare you for crosswind takeoff and landings. In the most basic sense,
slipping flight is uncoordinated flight. Anytime the model is flown with a sideslip condition (i.e., not going where the nose
is pointed), it is slipping. While it‘s a poor technique to use during turns (discussed earlier), slips can be a very useful
technique during crosswind takeoffs and landings. The second common use of slips is to increase the rate of descent by
increasing the drag on the airplane.
With an aileron-equipped model, it is possible to yaw the aircraft one direction, and roll the aircraft in the opposite
direction, causing any turning tendencies to be nullified (i.e. the model continues flying straight ahead). Used in this
manner, the aircraft will be flying sideways through the air and is known as a forward slip (as the aircraft continues
heading “forward”). This significantly increases the drag on the model and thus increases the rate of descent. This is
helpful when you are above your intended flight path and need to increase drag to get back on path.
To practice forward slips and compare their effectiveness in increasing drag, we must compare the rate of descent
between an idle descent rate and an idle “slipping” descent rate.
To start, set up a descent with the throttle closed and mentally record how fast the model descends. Then, after climbing
back up to altitude, set up another idle descent. Once established, roll into a 15-20 degree bank in one direction. Add
enough opposite rudder (i.e. right aileron/left rudder) to stop any turning tendencies and fly straight ahead. Notice the
increased rate of descent. To recover, simply neutralize your cross control inputs and the model will fly normally.
Practice with several different bank angles, adjusting the rudder to maintain a slip with no heading change.
The more common use of a slip is in crosswind takeoffs and landings. This will be explained in the next section but suffice
to say that even Jet Transport Aircraft use slips when taking off and landing in crosswinds. Basically, by de-linking the
rudder with the aileron in a slip we can control bank and yaw independently, allowing precise heading and drift control.