Pre-Solo Training Program Flight Briefing: Lesson 7 Steep Turns, Slips, and Spin Avoidance/Recovery...

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

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.


Steep Turns

A steep turn is defined as any turn in which an over-banking 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.

– 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.


Steep Turns

Components of forces in a turn.


Load Factor

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.


Relationship Between Bank Angle and Load Factor


Over-banking Tendency

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.)


Maintaining Altitude

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.


Maintaining Airspeed

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.


Flying Steep Turns

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.


Rolling Out

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.


Flying the Steep Turn


Slips

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.


Slips

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.


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.


Why Slip?

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.


Why Slip?

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).


How to Slip

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.


Stall Review

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.


Flying Stalls (Power off)


Flying Stalls (Power on)


The Secondary Stall

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.


Secondary Stall


Spin Theory

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.


Asymmetric Stall

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.


Stall Leading to Spin

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.


What a Spin Looks Like


Four Phases of a Spin

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.


To Recover from an upright Spin (PARE):

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.


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.”


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.


Determining Crosswind Component


On Today’s Flight

We’ll practice making steep turns We’ll review and practice stalls with different

power settings and flap configurations We’ll practice making slips


Review Questions

What angle of bank constitutes a steep turn?

How do you maintain altitude and airspeed in a steep turn?

What are the two types of slips?

What differentiates one from the other?

What condition is necessary for a spin to develop?

What is the easiest way to recover from an inadvertent spin?

Write down your answers before continuing to next slide


Review Answers

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.


Today in the Pattern

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)

Pre-Solo Training Program Flight Briefing: Lesson 7 Steep Turns, Slips, and Spin Avoidance/Recovery...

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