Flight Training - March 2014 - 22

CHECKRIDE

By Bob Schmelzer

SLIPPERY FLYING

THE DUO OF CROSS-CONTROLLED MANEUVERS

he ability to perform slips effectively and confidently is a tool
you will use not only on your checkride, but on nearly every
one of your flights for as long as you fly. Of course, there are
the accidental slips that occur when a pilot doesn't apply
enough rudder pressure during turns, and doing those on your checkride should be kept to a minimum, if possible.
The designated pilot examiner (DPE)
will ask you to demonstrate a couple of
intentional slips that are an important part
of every good pilot's bag of skills. There
are two types of intentional slips: sideslips
and forward slips. And while you may
rarely need to do forward slips, you'll perform a sideslip any time you correct for a
crosswind during landing-which is nearly
every flight.
Although the primary difference
between the two is simply how much rudder deflection is used, they really are two
very different maneuvers, with two very
different purposes. The forward slip is a
great device whenever you need to lose
excess altitude and/or airspeed-usually
for the purpose of landing-but it also can
be helpful during an emergency descent.
True, with proper approach planning,
forward slips are rarely necessary, but we
all have our days.
During the checkride, examiners prefer
to see applicants who employ an unsolicited forward slip maneuver if they are
high on approach to a simulated engineout landing, or during another of their
landing approaches-thus demonstrating

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that correlation-level learning has been
achieved. When accomplishing a forward
slip, first retard the throttle to idle. Leaving
power on (above idle) renders the forward
slip highly ineffective. This is a surprisingly common error among applicants.
Also, be sure to fully extend the flaps
(unless prohibited by the manufacturer)
to increase the drag component. This
will increase the slip's effectiveness.
Next, make your cross-control inputs by
smoothly and simultaneously applying
enough upwind aileron to maintain the
desired ground track as you apply full
opposite rudder while lowering the pitch
attitude to maintain the desired descent
airspeed. Failure to adequately lower
the nose is a common error that leads to
airspeed decay toward stall speed, often
while close to the ground in a cross-control configuration. This scares examiners,
the results of which are never pleasant.
Finally, when you reach your desired
approach profile, simply recover from the
forward slip by neutralizing the crosscontrol inputs and adjusting the pitch
attitude. Continue the approach or descent
as appropriate to the situation.

When making your crosswind landing,
which is also a requirement for all checkrides when an actual crosswind exists,
it's time to demonstrate your sideslip
maneuver. For the sideslip, instead of using
full rudder, apply only as much rudder as
is needed to align the nose (longitudinal
axis) with the runway while simultaneously applying enough upwind aileron
to keep the airplane tracking along the
runway centerline (no sideways drift). Be
prepared to adjust both rudder and aileron
inputs for changing wind conditions.
What makes the sideslip more challenging is the fact that as the airspeed decays
during the landing flare, the flight controls
become gradually less effective, demanding ever-increasing control inputs to
maintain aircraft directional control. And
in gusty winds, this can be a huge challenge, especially for student pilots. During
training, sideslips often are initiated
moments before the actual touchdown.
However, beginning the sideslip earlier on
the final approach is a powerful teaching
technique, because it permits a longer
exposure to the maneuver and therefore more learning opportunity for each
crosswind landing made. The number of
aircraft bent each year while landing in
crosswinds is strong evidence that the
sideslip maneuver not only is difficult to
master, but also proof that its mastery is
paramount.
Whatever you do, make sure to spend
enough quality time learning, practicing, and mastering these important slip
maneuvers. Remember: Full rudder equals
forward slip; partial rudder equals sideslip.
The extra time and effort you spend now
will be well-rewarded-not just on your
checkride day, but every time you fly when
there's a crosswind.
Bob Schmelzer is a Chicago-area designated pilot
examiner, a United Airlines captain, and a Boeing
777 line check airman. He has been an active flight
instructor since 1972.

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Flight Training - March 2014

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