Transcript Lesson 7

Pre-Solo Training Program
Flight Briefing: Lesson 7
Steep Turns, Slips, and
Spin Avoidance/Recovery
In cooperation with Mid Island Air
Service, Inc. Brookhaven, NY
(Michael Bellenir, CFI)
Lesson 7 Objectives
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In this briefing, you will learn how to perform
turns at a steep bank angle. You will also
learn how to perform a slip, and learn about
spin aviodance and spin recovery procedures.
Upon completion of this briefing, you will
perform steep turns, demonstrate slips, and
practice both power-on and power-off stalls.
Flight Briefing: Lesson 7
Steep Turns
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A steep turn is defined as any turn in which an overbanking tendency is evident.
It is performed at a steeper than normal bank angle,
usually 45 degrees or more.
A steep turn can be challenging because of several
different components.
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In a steep turn, the airplane will generally not correct back
to wings level automatically. In steep turns, the angle of
bank tends to keep getting steeper unless corrected.
A steep turn, like any turn, redirects lift from the vertical
towards the horizontal. Thus, steep turns especially tend to
cause the airplane to lose altitude.
Flight Briefing: Lesson 7
Steep Turns
Components of forces in a turn.
Flight Briefing: Lesson 7
Load Factor
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Because the total lift component must be increased in the turn to
maintain altitude, the load factor also increases.
The steeper the bank, the higher the load factor, assuming altitude is
maintained.
In a normal level turn at 30 degrees of bank, the load factor would be
very close to 1, and you would feel a normal gravitational load of 1 G.
At 45 degrees of bank, the load factor would be 1.4, and you would
feel a gravitational load of 1.4 G.
At 60 degrees of bank, the load factor would be 2.0, and you would
feel a gravitational load of 2 Gs.
At 70 degrees of bank, the load factor would be 3.0, and you would
feel a gravitational load of 3 Gs. This is definitely an aerobatic
maneuver!
Load factor rises exponentially with bank angle.
Flight Briefing: Lesson 7
Relationship Between Bank Angle and
Load Factor
Flight Briefing: Lesson 7
Over-banking Tendency
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Because of increasing horizontal component
of lift, the airplane will turn tighter, resulting in
a steeper bank that further increases the
horizontal component of lift…
To counter the over-banking tendency, it is
usually required to apply some aileron
pressure away from the direction of turn.
(Slight pressure towards high wing in a steep
turn.)
Flight Briefing: Lesson 7
Maintaining Altitude
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As the horizontal component of lift
increases, the vertical component of lift
decreases. Back pressure will be
required to increase the total lift of the
airplane to not lose altitude.
Make sure to keep the nose up enough in
the steep turn so you don’t lose altitude.
Don’t let the nose drop.
Flight Briefing: Lesson 7
Maintaining Airspeed
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A higher load factor on the airplane
corresponds to higher drag.
Increased drag will tend to cause the
airplane to slow down slightly in the turn.
Compensate by adding power as required to
overcome the increase in drag.
Flight Briefing: Lesson 7
Flying Steep Turns
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Make sure the area is clear and that speed and altitude are
appropriate.
To initiate the steep turn, smoothly apply rudder pressure in
the desired direction of turn, coordinate with aileron, and
add a small amount of power.
Smoothly set a bank of about 45 degrees. When rolling
though about 30 degrees of bank, back pressure will be
required.
When reaching the desired bank, neutralize the rudders,
and apply slight opposite aileron to prevent over-banking.
Maintain altitude with back pressure. Turn should be tight,
but very stabilized.
Flight Briefing: Lesson 7
Rolling Out
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At the completion of the steep turn, initiate
the roll-out with smooth application of rudder
pressure, and coordinated aileron.
Release the back pressure and reduce the
power while rolling out, or the airplane will
tend to enter a climb.
Complete a steep turn in the opposite
direction.
Flight Briefing: Lesson 7
Flying the Steep Turn
Flight Briefing: Lesson 7
Slips
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A slip is a maneuver in which the airplane
effectively flies sideways through the air.
Airflow hits the side of the fuselage in
addition to the normal leading edges.
Because the air stream is contacting a much
larger surface area than normal, the drag on
the airplane is increased.
The amount of increase in drag varies with
the degree of slip. More slip = more drag.
Flight Briefing: Lesson 7
Slips
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There are two main types of slips: the
forward slip, and the side slip.
The difference is the direction in which the
airplane moves during the slip. In the
forward slip, the airplane is kept tracking on
its original flight path (direction); In the side
slip, the airplane stays pointed in the same
direction, but is banked and yawed so that its
flight path is directed to one side.
Flight Briefing: Lesson 7
Types of Slips
From the pilot’s seat, these will feel exactly the same; the airplane
is in fact, doing the same thing, the difference is the direction you
are traveling relative to your original flight path.
Flight Briefing: Lesson 7
Why Slip?
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Because of the increase in drag on the airplane
during a slip, a slip can be used to increase
descent rate or slow down. For example, a
pilot slightly high on an approach might use a
forward slip to descend back to the glide path.
A side slip can be used to counter the effect of
a crosswind. If a pilot applies a side slip into
the wind equal to the crosswind component, it
will effectively cancel out the effect of the
crosswind.
Flight Briefing: Lesson 7
Why Slip?
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Slips can also be used to lose altitude faster
if necessary in an emergency, to facilitate a
steep approach to a short runway where a
steep approach is necessary to clear
obstacles, or in place of flaps if the flaps
become unavailable (such as experiencing
an electric system failure in a plane with
electric flaps), or when flying a plane not
equipped with flaps (such as many antiques).
Flight Briefing: Lesson 7
How to Slip
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Think about where you want the airplane to go or
where you want it to point.
Apply aileron in one direction, the rudder in the
opposite direction.
Keep track of where you are tracking/pointing, and
balance the ailerons and rudder pressures against
each other to maintain your desired track/orientation.
This is a cross-controlled maneuver, so keep the angle
of attack above critical by maintaining a proper
airspeed. Stalling in a slip is the setup for a spin entry.
Flight Briefing: Lesson 7
Stall Review
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A wing stalls upon reaching the critical angle
of attack.
To perform a stall, slow down and increase
the angle of attack with back-pressure.
At the stall, recover by reducing angle of
attack by relaxing back-pressure, regaining
normal flying speed. Then recover lost
altitude by establishing best climb with full
power.
Flight Briefing: Lesson 7
Flying Stalls (Power off)
Flight Briefing: Lesson 7
Flying Stalls (Power on)
Flight Briefing: Lesson 7
The Secondary Stall
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A secondary stall usually occurs when an airplane is
recovered abruptly from a stalled condition, and
stalls again.
A secondary stall can also occur from an incomplete
or improper stall recovery.
To avoid a secondary stall, recover gently, and avoid
pulling up aggressively during the stall recovery.
Each successive secondary stall tends to be deeper
than the previous one, with increasing altitude loss.
Flight Briefing: Lesson 7
Secondary Stall
Flight Briefing: Lesson 7
Spin Theory
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A spin is an aggravated stall with
“autorotation.”
Autorotation means the airplane will rotate
(spin) without a direct control input from the
pilot commanding it to do so.
Autorotation occurs when the wings are
stalled at slightly different times, or are
stalled by different amounts.
Flight Briefing: Lesson 7
Asymmetric Stall
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The wings can stall at slightly different times if the pilot
enters a stall and the airplane is not properly
coordinated. If one wing is going faster than the other,
the slower wing will usually stall first, causing a roll
towards that wing.
The wings can be stalled different amounts by
improperly using aileron in a stall. Use of aileron
increases the angle of attack on one wing while
decreasing angle of attack on the other. The more
deeply stalled wing will drop more, causing the other
wing to become even less stalled.
Flight Briefing: Lesson 7
Stall Leading to Spin
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An airplane cannot spin unless it is first stalled.
Most training aircraft (including the one we are flying)
are stable enough to resist spinning.
Usually, improper use of controls or improper
coordination results in simply dropping a wing.
Understanding how a spin happens and how to recover
is important for your understanding of aerodynamics
and safety of flight.
We will not be doing spins as part of your training. It is
not required to do spins for you to get your pilot
certificate, and in fact spins are not authorized in the
aircraft we use for training. However, understanding
spins is the key to spin avoidance and recovery.
Flight Briefing: Lesson 7
What a Spin Looks Like
Flight Briefing: Lesson 7
Four Phases of a Spin
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Entry: the pilot, either accidentally or intentionally,
provides the necessary elements for a spin to occur.
Incipient spin: from the point of the stall, through the
start of rotation, to the point where the spin is
considered developed.
Developed spin: when the rotation rate and descent
rate stabilize and the flight path becomes nearly
vertical.
Recovery: when the rotation rate slows, is stopped,
and the angle of attack is reduced to below the critical
angle of attack.
Flight Briefing: Lesson 7
To Recover from an upright Spin (PARE):
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Reduce the Power to idle
Neutralize the Ailerons
Apply Rudder pressure opposite the direction
of rotation.
Apply forward Elevator to break the stall.
When rotation stops, neutralize the rudder.
Recover smoothly from the resulting dive.
Flight Briefing: Lesson 7
Flight Briefing: Lesson 7
Spin Recovery
Per FAA Flight Instructor Bulletin #18:
“Recoveries in those airplanes approved for
intentional spins are usually rapid, and, in
some airplanes, may occur merely by
relaxing the pro-spin rudder and elevator
deflections. However, positive spin recovery
control inputs should be used regardless of
the phase of the spin during which recovery
is initiated.”
Flight Briefing: Lesson 7
Alternate Spin Recovery
 If
you spin with flaps extended, retract
the flaps immediately.
 Be careful when near stall speed.
Maintain a high level of alertness at
low altitudes and speeds, pay attention
to the warning signs, stay out of
hazardous situations, and you should
be safe from spins. Flight Briefing: Lesson 7
Determining Crosswind Component
Flight Briefing: Lesson 7
On Today’s Flight
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We’ll practice making steep turns
We’ll review and practice stalls with different
power settings and flap configurations
We’ll practice making slips
Flight Briefing: Lesson 7
Review Questions
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What angle of bank constitutes a steep turn?
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How do you maintain altitude and airspeed in a steep turn?
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What are the two types of slips?
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What differentiates one from the other?
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What condition is necessary for a spin to develop?
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What is the easiest way to recover from an inadvertent spin?
Write down your answers before
continuing to next slide
Flight Briefing: Lesson 7
Review Answers
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What angle of bank constitutes a steep turn?
One that produces over-banking tendency (typically 45 degrees or
more).
How do you maintain altitude and airspeed in a steep turn?
Increase back pressure and add power
What are the two types of slips?
Forward slip and side slip
What differentiates one from the other?
The direction which the aircraft tracks across the ground
What condition is necessary for a spin to develop?
The wing must be stalled
What is the easiest way to recover from an inadvertent spin?
Relax pro-spin rudder and elevator deflections
Review any missed questions before
continuing to today’s flight.
Flight Briefing: Lesson 7
Today in the Pattern
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Practice using a slip to landing.
Be especially mindful of your airspeed and
aircraft handling on base and final. Make
sure you’re comfortably above a stall.
Thanks to Mid Island Air Service, Inc.
Brookhaven, NY (Michael Bellenir, CFI)
Flight Briefing: Lesson 7