Steep Turns

WARNING:
All procedures are GENERALIZED.
Fly the maneuver in accordance with the Pilot Operating Handbook (POH)
and/or current Standard Operating Procedures (SOPs)

• 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

• To fully appreciate steep turns, a full review of turn performance is required
  • These principles include:
    • Turn performance review
    • Rate and radius of turn review
    • Load factor review
    • Overbanking review
    • Coordination throughout turns review

• 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

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• 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

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, V_A, or V_O, 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

• 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 (Airplane) Steep Turns Airman Certification Standards:

  • Objective: To determine whether the applicant exhibits satisfactory knowledge, risk management, and skills associated with steep turns
  • References: FAA-H-8083-2 (Risk Management Handbook), FAA-H-8083-3 (Airplane Flying Handbook), FAA-H-8083-25 (Pilot Handbook of Aeronautical Knowledge); POH/AFM
  • Private Pilot (Airplane) Steep Turns Lesson Plan

  
  

  Private Pilot (Airplane) Steep Turns Knowledge:

  The applicant demonstrates an understanding of:

  • PA.V.A.K1:

    How to conduct a proper steep turn.

  • PA.V.A.K2:

    Aerodynamics associated with steep turns, to include:

    • PA.V.A.K2a:

      Maintaining coordinated flight.

    • PA.V.A.K2b:

      Overbanking tendencies.

    • PA.V.A.K2c:

      Maneuvering speed, including the impact of weight changes.

    • PA.V.A.K2d:

      Load factor and accelerated stalls.

    • PA.V.A.K2e:

      Rate and radius of turn.

  
  

  Private Pilot (Airplane) 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.

  
  

  Private Pilot (Airplane) Steep Turns Skills:

  The applicant exhibits the skills to:

  • PA.V.A.S1:

    Clear the area.

  • PA.V.A.S2:

    Establish the manufacturer's recommended airspeed; or if one is not available, an airspeed not to exceed the maneuvering speed V_a.

  • 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°.

• Commercial Pilot (Airplane) Steep Turns Airman Certification Standards:

  • Objective: To determine whether the applicant exhibits satisfactory knowledge, risk management, and skills associated with steep turns
  • Note: See Appendix 3: Aircraft, Equipment, and Operational Requirements & Limitations for information related to this Task
  • References: FAA-H-8083-2 (Risk Management Handbook), FAA-H-8083-3 (Airplane Flying Handbook), FAA-H-8083-25 (Pilot Handbook of Aeronautical Knowledge); POH/AFM
  • Commercial Pilot (Airplane) Steep Turns Lesson Plan

  
  

  Commercial Pilot (Airplane) Steep Turns Knowledge:

  The applicant demonstrates an understanding of:

  • PA.V.B.K1:

    How to conduct a proper steep turn.

  • PA.V.B.K2:

    Aerodynamics associated with steep turns, including:

    • PA.V.B.K2a:

      Maintaining coordinated flight.

    • PA.V.B.K2b:

      Overbanking tendencies.

    • PA.V.B.K2c:

      Maneuvering speed, including the impact of weight changes.

    • PA.V.B.K2d:

      Load factor and accelerated stalls.

    • PA.V.B.K2e:

      Rate and radius of turn.

  
  

  Commercial Pilot (Airplane) Steep Turns Risk Management:

  The applicant is able to identify, assess, and mitigate risk associated with:

  • CA.V.A.R1:

    Division of attention between aircraft control and orientation.

  • CA.V.A.R2:

    Collision hazards.

  • CA.V.A.R3:

    Low altitude maneuvering, including stall, spin, or controlled flight into terrain (CFIT).

  • CA.V.A.R4:

    Distractions, improper task management, loss of situational awareness, or disorientation.

  • CA.V.A.R5:

    Uncoordinated flight.

  
  

  Commercial Pilot (Airplane) Steep Turns Skills:

  The applicant exhibits the skills to:

  • CA.V.A.S1:

    Clear the area.

  • CA.V.A.S2:

    Establish the manufacturer's recommended airspeed; or if one is not available, an airspeed not to exceed maneuvering speed (VA).

  • CA.V.A.S3:

    Roll into a coordinated 360° steep turn with approximately a 50° bank.

  • CA.V.A.S4:

    Perform the Task in the opposite direction.

  • CA.V.A.S5:

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

• National Transportation Safety Board (NTSB) Identification: CEN20LA357:
  • The NTSB determines the probable cause(s) of this accident to be: The pilot's failure to maintain airspeed while maneuvering at low altitude, which resulted in an aerodynamic stall and collision with terrain