Steep Turns

What is a Steep Turn?

Steep turns consist of single to multiple 360° turns, in either or both directions, using a bank angle between 45° and 60°.

When performing steep turns, pilots are exposed to:

• Higher load factors.
• The airplane’s inherent overbanking tendency.
• The need for additional power to maintain airspeed.
• The need for substantial pitch control pressures to maintain the vertical component of lift.

Turning Flight

When the wings are banked, lift is separated into vertical and horizontal components. The horizontal component of lift causes the airplane to turn. Centrifugal force tries to pull the airplane away from the direction of the turn, counteracting the horizontal component of lift.

Lift and Drag in a Turn

Lift: The greater the bank, the greater the rate of turn will be because more lift goes into the horizontal component. Total lift remains constant due to a decrease in the vertical component.

Drag: To maintain altitude in a turn, back pressure on the pitch control must be increased. Drag increases and additional power is needed to maintain airspeed.

Rate of Turn

The rate of turn is the number of degrees of heading change that an aircraft makes per second.

At a given airspeed, the turn rate increases if the bank angle increases. Likewise, if airspeed is held constant, the rate of turn increases if the bank angle is increased.

Rate of Turn = (1,091 × tanØ) ÷ KTAS

Radius of Turn

At a given bank angle, a higher airspeed makes the radius of turn larger because the airplane turns slower. The higher airspeed causes the aircraft to travel through a longer arc. To compensate for the increase in airspeed, the bank angle would need to be increased.

Radius of Turn = KTAS² ÷ (11.26 × tanØ)

The Need for Additional Power in a Steep Turn

As an airplane is banked, back pressure on the pitch control is applied to maintain level flight. The increase in lift results in more drag and a slower airspeed.

The turn also increases the load factor and stalling speed. Power must be increased to overcome drag and maintain a margin above the stall speed.

Correcting for Left-Turning Tendencies

The effects of torque and P-factor vary considerably throughout each phase of flight. Pilots must learn to compensate for these forces through the use of aileron and rudder inputs when appropriate.

During Left and Right Turns

• Greater rudder pressure is required when entering right turns than left.
• The airplane tends to skid in left turns (less, or even a slight opposite rudder pressure is required).
• The airplane tends to slip in right turns (slight right rudder pressure may be required throughout the turn).

Overbanking Tendency

In a steeply-banked turn, airplanes exhibit a tendency to continue rolling in the direction of the bank unless deliberate and opposite aileron pressure is held against the bank. The tendency to continue rolling is called overbanking.

Overbanking occurs as a result of differences in lift between the wings. The wing on the outside of the turn travels a longer path than the inside wing, yet both complete their respective paths in the same unit of time. Therefore, the outside wing travels at a faster airspeed than the inside wing, and, as a result, it develops more lift.

Load Factor

Load factor is the ratio of the total load supported by the airplane’s wing to the total weight of the airplane.

Load Factor = Lift ÷ Weight

Effect of Turns on Load Factor

As an airplane is banked, more lift is required to maintain level flight due to the inclination of the lift vector. Total lift must increase to maintain the same vertical component of lift equal to the weight. Therefore, load factor increases.

The following formula computes the load factor in a particular bank angle, represented by the Greek letter theta (Ø).

Load Factor = 1 ÷ cosØ

Maneuvering Speed

The design maneuvering speed (V_A) is a structural design airspeed used in determining the strength requirements for the airplane and its control surfaces. When at or below V_A, the pilot can move a single flight control, one time, to its full deflection, in smooth air, without risk of damage to the airplane.

Pilots should not interpret the maneuvering speed as:

• A speed that permits multiple full control inputs at the same time. This creates bending and twisting forces on the airframe (e.g., “Rolling Gs”).
• A gust penetration speed, although some manufacturers use V_A for that purpose. The AFM/POH may provide a separate turbulence penetration speed (V_B).

Effect of Weight on Maneuvering Speed

The maneuvering speed (V_A or V_O) published in the AFM/POH is valid for operation at the weight stated, typically max gross weight. It decreases as its weight decreases.

Two concepts can explain the effect of weight on maneuvering speed:

• Newton’s Second Law of Motion (F = MA)
• Its relationship to the angle of attack (turbulence and pull-ups)

Newton’s Second Law of Motion (F = MA)

When an airplane is subjected to an external force, such as the aerodynamic force from a control surface, it responds by accelerating (rotational acceleration) around one of its axes. This was stated in Newton’s Second Law of Motion, which can be written in the following way.

Acceleration = Force ÷ Mass

For a given control force, acceleration increases when weight (mass) decreases. Higher acceleration results in higher loads on the airplane structure. Therefore, as the airplane’s weight decreases, maneuvering speed must decrease.

Angle of Attack (Turbulence and Pull-Ups)

Additional weight requires the aircraft to fly at a higher AOA to sustain flight. Since the heavier airplane is closer to the critical AOA (approximately 18°), it will stall more quickly following an abrupt pull-up or encounter with turbulence. This leaves it less susceptible to excessive load factors than the lighter airplane.

Calculating Maneuvering Speed

If not specified in the AFM/POH, the maneuvering speed for a lower operating weight can be approximated with the following formula.

V_A1 = V_A2 × √(Current Weight ÷ Maximum Gross Weight)

• V_A1 is the calculated maneuvering speed for the current weight.
• V_A2 is the AFM/POH maneuvering speed at the maximum gross weight.

It can be approximated for airplanes without a published V_A with the following formula.

V_A = V_S1 × √(Positive Limit Load Factor)

How to Perform a Steep Turn

Pre-Maneuver Checks and Configuration

• Clear the area
• Heading established and noted:
• Select a suitable reference point on the horizon
• Align the heading bug, if equipped, to the reference point
• Altitude established:
• No lower than 1,500′ AGL [ASEL]

• No lower than 3,000′ AGL [AMEL]
• Position near a suitable emergency landing area
• Set power and aircraft configuration:
• Perform the clean (cruise) configuration flow
• Establish the recommended airspeed, or if not stated, an airspeed at or below V_A or V_O

Use of Trim

Steep turns can be performed with or without trim. Using trim reduces the need for large control inputs and allows the pilot to keep a light feel on the controls during the turn.

If using trim, adjust it as the bank angle goes beyond 30°. During the rollout, apply forward pressure on the pitch control to prevent “ballooning” (gaining altitude) until the trim is reset.

Entry

1. Note the pitch and power settings for use during the rollout.
2. Smoothly and firmly apply aileron and rudder pressure in the direction of the desired turn.
3. As the bank angle increases, apply back pressure on the pitch control to maintain level flight. Apply trim if desired.
4. Smoothly add power to maintain airspeed.

1. When the bank angle has reached 45° or 50°, the pitch reference point on the windshield should be just a slight bit higher than for a 30° bank turn.

Execution

• Use the aileron control to keep the bank angle from increasing (correction for overbanking tendency).
• For airspeed deviations, make power adjustments.
• For altitude deviations, make slight pitch and bank angle adjustments:
• If altitude is decreasing, momentarily reduce the bank angle a few degrees.
• If altitude is increasing, momentarily increase the bank angle a few degrees.

Rollout

1. Lead the rollout heading by one-half the number of degrees of the angle of bank (e.g., 50° bank ÷ 2 = 25° lead).
2. Simultaneously apply forward pressure to level the pitch attitude and reduce the power back to the entry setting.
3. Immediately roll into a turn in the opposite direction, if appropriate.

Exit

1. Return to cruise speed, trimming as necessary.
2. Complete the cruise checklist.

Common Errors for Steep Turns

• Failure to scan for traffic before and during the maneuver
• Inadequate pitch control on entry or rollout
• Gaining altitude in right turns and losing altitude in left turns (when flown from the left seat)
• Failure to maintain a constant bank angle
• Poor flight control coordination
• Ineffective use of trim or power

• Loss of orientation
• Overcontrolling (low and fast to high and slow and vice-versa)
• Performing by reference to the flight instruments rather than visual references
• Attempting to start the rollout prematurely
• Not completing the turn on the designated heading or reference

Airman Certification Standards for Steep Turns