Steep Turns

Introduction:

  • Steep turns develop a pilot's skill in flight control smoothness and coordination during high angles of banks, an awareness of the airplane's orientation to outside references, division of attention between flight control applications, and the constant need to scan for hazards and other traffic in the area
  • Maximum performance turns are defined as using the fastest rate of turn and shortest radius
  • These turns will cause a much higher stalling speed
    • Limiting load factor determines the maximum bank without stalling

Steep Turns Overview:

  • Steep turns consist of single to multiple 360° and 720° turns, in either or both directions, using a bank angle between 45° and 60°
  • Steep turns help pilots understand:
    • Higher G forces experienced during a turn
    • An airplane's inherent overbanking tendency when the bank angle exceeds 30°
    • Significant loss of the vertical component of lift when the wings are steeply banked
    • Substantial pitch control pressures
    • The need for additional power to maintain airspeed during the turn

Steep Turns Performance Review:

  • To fully appreciate steep turns, a full review of turn performance is required
  • Turn Performance Review:

    • When banking an airplane for a level turn, the total lift divides into vertical and horizontal components of lift
    • To maintain altitude at a constant airspeed, the pilot increases the angle of attack (AOA) to ensure that the vertical component of lift is sufficient to maintain altitude
    • The pilot adds power as needed to maintain airspeed
    • For a steep turn, as in any level turn, the horizontal component of lift provides the necessary force to turn the airplane
    • Regardless of the airspeed or airplane, for a given bank angle in a level altitude turn, the same load factor will always be produced
  • Rate and Radius of Turns Review:

    • Rate of Turn:

      • The rate depends on a set bank angle at a set speed [Figure 2]
      • The standard rate of turn is 3° per second
      • Speed & Rate of Turn:
        • If the aircraft increases speed without changing the bank angle, the rate of turn decreases
        • If the aircraft decreases speed without changing the bank angle, the rate of turn increases
      • Bank Angle & Rate of Turn:
        • If the aircraft bank angle increases without changing airspeed, the rate of turn increases
        • If the aircraft bank angle decreases without changing airspeed, the rate of turn decreases
      • Speed and bank angle, therefore, vary inversely to maintain a standard rate turn
        • This is important in the instrument environment, such as when holding or on an instrument approach
      • A rule of thumb for determining the standard rate turn is to divide the airspeed by ten and add 5
        • Example: an aircraft with an airspeed of 90 knots takes a bank angle of 16° to maintain a standard rate turn (90 ÷ by 10 + 5 = 14°)
    • Radius of Turn:

      • The radius of turn varies with changes in either speed or bank [Figure 2]
      • Speed & Radius of Turn:
        • If the speed increases without changing the bank angle, the radius of turn increases
        • If the speed decreases without changing the bank angle, the radius of turn decreases
      • Bank Angle & Radius of Turn:
        • If the speed is constant, increasing the bank angle decreases the radius of turn
        • If the speed is constant, decreasing the bank angle increases the radius of turn
      • Therefore, intercepting a course at a higher speed requires more distance and, therefore, requires a longer lead
      • If the speed is slowed considerably in preparation for holding or an approach, a shorter lead is needed than that required for cruise flight
      • Instrument Flying Handbook. Figure 2-14, Rate and Radius of Turns
        Instrument Flying Handbook, Turns
      • Instrument Flying Handbook. Figure 2-14, Rate and Radius of Turns
        Instrument Flying Handbook, Turns
  • Load Factor Review:

    • The load factor is the vector addition of gravity and centrifugal force
      • When the bank becomes steep as in a level altitude 45° banked turn, the resulting load factor is 1.41
      • In a level altitude 60° banked turn, the resulting load factor is 2.0
      • To put this in perspective, with a load factor of 2.0, the effective weight of the aircraft (and its occupants) doubles
    • Pilots may have difficulty with orientation and movement when first experiencing these forces
    • Pilots should also understand that load factors increase dramatically during a level turn beyond 60° of bank
      • Note that the design of a standard category general aviation airplane accommodates a load factor up to 3.8. A level turn using 75° of bank exceeds that limit
    • Because of higher load factors, steep turns should be performed at an airspeed that does not exceed the airplane's design maneuvering speed (VA) or operating maneuvering speed (VO)
    • Maximum turning performance for a given speed is accomplished when an airplane has a high angle of bank
    • Each airplane's level turning performance is limited by structural and aerodynamic design, as well as available power
      • The airplane's limiting load factor determines the maximum bank angle that can be maintained in level flight without exceeding the airplane's structural limitations or stalling
    • As the load factor increases, so does the stalling speed
      • For example, if an airplane stalls in level flight at 50 knots, it will stall at 60 knots in a 45° steep turn while maintaining altitude
      • It will stall at 70 knots if the bank is increased to 60°
      • Stalling speed increases at the square root of the load factor
    • As the bank angle increases in level flight, the margin between stalling speed and maneuvering speed decreases
      • At speeds at or below VA or VO, the airplane will stall before exceeding the design load limit
  • Overbanking Review:

    • In addition to the increased load factors, the airplane will exhibit what is called "overbanking tendency"
    • In most flight maneuvers, bank angles are shallow enough that the airplane exhibits positive or neutral stability about the longitudinal axis
      • However, as bank angles steepen, the airplane will continue rolling in the direction of the bank unless deliberate and opposite aileron pressure is held
    • Pilots should also be mindful of the various left-turning tendencies, such as P-factor, which require effective rudder/aileron coordination
    • While performing a steep turn, a significant component of yaw is experienced as motion away from and toward the earth's surface, which may seem confusing when first experienced
    • Before starting any practice maneuver, the pilot ensures that the area is clear of air traffic and other hazards
      • Further, distant references should be chosen to allow the pilot to assess when to begin rollout from the turn
  • Coordination Throughout Turns:

    • A slipping turn results from the aircraft not turning at the rate appropriate to the bank being used, and the aircraft falls to the inside of the turn [Figure 3]
    • The aircraft is banked too much for the rate of turn, so the horizontal lift component is greater than the centrifugal force
    • A skidding turn results from an excess of centrifugal force over the horizontal lift component, pulling the aircraft toward the outside of the turn [Figure 3]
    • The rate of turn is too great for the angle of bank, so the horizontal lift component is less than the centrifugal force
    • The ball instrument indicates the quality of the turn and should be centered when the wings are banked
    • If the ball is off-center on the side toward the turn, the aircraft is slipping, requiring added rudder pressure on that side to increase the rate of turn
      • Also, reducing the bank angle without changing the rudder pressure will help coordinate the turn
    • If the ball is off-center on the side away from the turn, the aircraft is skidding, requiring rudder pressure on that side to be relaxed to decrease the rate of turn
      • Also, increasing the bank angle without changing the rudder pressure will help coordinate the turn
    • The ball should be in the center when the wings are level; use rudder and/or aileron trim if available
    • The increase in induced drag (caused by the increase in the angle of attack necessary to maintain altitude) results in a minor loss of airspeed if the power setting is not changed

Steep Turns Procedure:

WARNING:
All procedures are GENERALIZED.
Always fly per Pilot Operating Handbook procedures,
observing any relevant Standard Operating Procedures (SOPs)


  1. Perform clearing turns
  2. Select a prominent visual reference point ahead of the airplane and out toward the horizon
  3. Adjust the pitch and power to maintain altitude
    • Trim as necessary
  4. Maintain heading and note the pitch attitude required for level flight
  5. After establishing the manufacturer's recommended entry speed, VA, or VO, as applicable, the airplane should be smoothly rolled into a predetermined bank angle between 45° and 60°
    • As the bank angle is being established, generally prior to 30° of bank, elevator back pressure should be smoothly applied to increase the AOA
      • Considerable force is required on the elevator control to hold the airplane in level flight
      • The decision whether to use trim depends on the airplane characteristics, speed of the trim system, and preference of the instructor and learner
    • Simultaneously, power sould be applied
      • as the AOA increases, so does drag, and additional power allows the airplane to maintain airspeed
    • Remain coordinated
    • Remember parallax error
  6. Rolling through 30° of bank, increase power to maintain airspeed
    • Increase pitch to maintain altitude
    • Trim as necessary
    • Pull back on the yoke will increase rate of turn but do not allow the aircraft to climb
  7. Reference the visual point selected earlier and roll out 20-25° before entry heading
  8. Through 30° of bank, decrease RPM
    • Decrease pitch
    • Trim nose down
  9. Return to wings level on entry heading, altitude, and airspeed
    • A good rule of thumb is to begin the rollout at 1/2 the number of degrees of bank prior to reaching the terminating heading
      • For example, if a steep turn was begun on a heading of 270° and if the bank angle is 60°, the pilot should begin the rollout 30° prior
    • While the rollout is being made, elevator back pressure, trim (if used), and power should be gradually reduced, as necessary, to maintain the altitude and airspeed
  10. Immediately roll into a bank in the opposite direction
    • Perform the maneuver once more in the opposite direction
  11. Upon rolling out after the second turn, resume normal cruise
    • Trim as necessary
  12. Complete the cruise checklist

Steep Turns Common Errors:

  • Failure to adequately clear the area
  • Inadequate back-elevator pressure control as power is reduced, resulting in altitude loss
  • Excessive back-elevator pressure as power is reduced, resulting in altitude gain, followed by a rapid reduction in airspeed and "mushing"
    • Remember, the aircraft stalls at a higher airspeed when in high angles of bank
  • Inadequate compensation for adverse yaw during turns
  • Inadequate power management
  • Inability to adequately divide attention between airplane control and orientation
  • Inadequate pitch control on entry or rollout
  • Failure to maintain constant bank angle
  • Poor flight control coordination
  • Ineffective use of trim
  • Ineffective use of power
  • Inadequate airspeed control
  • Becoming disoriented
  • Performing by reference to the flight instruments rather than visual references
  • Failure to scan for other traffic during the maneuver
  • Attempting to start recovery prematurely
  • Failure to stop the turn on the designated heading

Private Pilot - Steep Turns Airman Certification Standards:

  • Objective: To determine the applicant exhibits satisfactory knowledge, risk management, and skills associated with steep turns
  • References: FAA-H-8083-2, FAA-H-8083-3, FAA-H-8083-25; POH/AFM
  • Steep turns lesson plan

Steep Turns Knowledge:

The applicant demonstrates understanding of:

Steep Turns Risk Management:

The applicant is able to identify, assess, and mitigate risk associated with:
  • PA.V.A.R1:

    Division of attention between aircraft control and orientation
  • PA.V.A.R2:

    Collision hazards
  • PA.V.A.R3:

    Low altitude maneuvering, including stall, spin, or controlled flight into terrain (CFIT)
  • PA.V.A.R4:

    Distractions, improper task management, loss of situational awareness, or disorientation
  • PA.V.A.R5:

    Uncoordinated flight

Steep Turns Skills:

The applicant exhibits the skill to:
  • PA.V.A.S1:

    Clear the area
  • PA.V.A.S3:

    Roll into a coordinated 360° steep turn with approximately a 45° bank
  • PA.V.A.S4:

    Perform the Task in the opposite direction, as specified by evaluator
  • PA.V.A.S5:

    Maintain the entry altitude ±100 feet, airspeed ±10 knots, bank ±5 degrees, and roll out on the entry heading ±10°

Steep Turns Case Studies:

Conclusion:

  • As PilotWorkshops state: "Steep turns demonstrate turn performance while practice division of attention, orientation, comfort with higher G-forces, overbanking tendency, and learning the control inputs required to maintain altitude at a constant airspeed during the turn"
  • Consider practicing maneuvers on a flight simulator to introduce yourself to maneuvers or knock off rust
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References: