Introduction
The objective of practicing steep turns is to develop a pilot’s skill in flight control smoothness and coordination, enhance situational awareness, and improve the division of attention between flight control applications and the need to scan for other traffic. Mastering steep turns prepares pilots to handle more advanced flight maneuvers.
Objectives
After this lesson, the learner will be able to:
- Describe the purpose and procedures for steep turns.
- Describe pilot sensations and control forces during steep turns.
- Discuss the aerodynamics of steep turns.
- Divide attention between aircraft control, orientation, and traffic avoidance.
- Perform a coordinated steep turn, maintaining bank angle and altitude, and roll out on a specific heading.
In addition, flight instructor applicants will be able to:
- Deliver effective instruction on the objectives.
- Analyze and correct common errors.
- Recall skill-related tolerances from the Airman Certification Standards.
Lesson Briefing
- What is a Steep Turn?
- The Need for Additional Power in a Steep Turn
- Correcting for Left-Turning Tendencies
- Overbanking Tendency
- Maneuvering Speed
- Load Factor
- Factors Affecting Stall Speed
- Turning Flight
- How to Perform a Steep Turn
- Common Errors for Steep Turns
- Risk Examples for Flight Maneuver and Stall Training
- Airman Certification Standards for Steep Turns
Scenario
You are flying down the Hudson River, making a scenic tour of New York City. The river is narrow, and the airspace is confining. When you decide to turn around, you see high-rise buildings along both shores and traffic crossing above and below you.
Describe and demonstrate how to reverse course using a steep turn.
Resources
- Airplane Flying Handbook (FAA-H-8083-3):
- Chapter 10: Performance Maneuvers
Schedule
- Lesson Briefing (0:20)
- Demonstrations and Practice (0:20)
- Lesson Debriefing (0:10)
Equipment
- Digital presentation tools or a whiteboard with markers and erasers
- Reference books and materials
- Spare notepads, pens, and highlighters
- Airplane models
- Airplane checklists
- Headsets and flight gear
Lesson Debriefing
The lesson concludes with a collaborative assessment and review focused on the objectives. The instructor also addresses any remaining learner questions and provides feedback on individual progress and performance.
Completion Standards
This lesson is complete when the lesson objectives are met and the learner’s knowledge, risk management, and skills are determined to be adequate for the stage of training. Ultimately, the learner must meet or exceed the Airman Certification Standards.
Lesson Content
What is a Steep Turn?
Steep turns consist of a single or multiple 360° turns in either or both directions, generally using a bank angle of 45° or 50° for training purposes. During the maneuver, pilots must maintain a constant altitude, airspeed, and bank angle.
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.
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.
Load Factor | Drag | Stall Speed | Power Required |
---|---|---|---|
Increases | Increases | Increases | Increases |
Correcting for Left-Turning Tendencies
Note: Torque and P-Factor create left-turning tendencies in airplanes with an engine mounted on the front (a “puller”, not a “pusher”) and a propeller rotating in a clockwise direction (as seen from the rear).
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 due to 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.
Note: Other factors, such as torque and inertia, may contribute to the overbanking tendency.
Maneuvering Speed
References: AC 23-19, SAIB CE-11-17
The design maneuvering speed (VA) is a structural design airspeed used to determine the strength requirements for the airplane and its control surfaces. When at or below VA, 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 VA for that purpose. The AFM/POH may provide a separate turbulence penetration speed (VB).
Effect of Weight on Maneuvering Speed
The maneuvering speed (VA or VO) published in the AFM/POH is valid for operation at the stated weight, typically max gross weight. It decreases as the 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.
Example: The heavier airplane’s wing (left) is 13.5° away from the critical angle of attack, while the lighter airplane’s wing (right) is 15° away. A strong gust of +5 Gs applied to both airplanes would cause the heavier airplane to stall, but not the lighter airplane. Therefore, the gust will exceed the lighter airplane’s structural limits (+3.8 Gs).
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.
VA1 = VA2 × √(Current Weight ÷ Maximum Gross Weight)
- VA1 is the calculated maneuvering speed for the current weight.
- VA2 is the AFM/POH maneuvering speed at the maximum gross weight.
It can be approximated for airplanes without a published VA with the following formula.
VA = VS1 × √(Positive Limit Load Factor)
Example: The square root of 3.8 Gs (normal category load limit) is roughly 1.95. A slightly lower number (1.7) should be used as a safety margin.
Load Factor
References: 14 CFR 23.2210, 14 CFR 23.2230
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
Examples:
- In a 30° bank, the load factor is +1.15 Gs.
- In a 45° bank, the load factor is +1.41 Gs.
- In a 60° bank, the load factor is +2 Gs.
Factors Affecting Stall Speed
Load Factor
A stall that occurs at speeds greater than the 1 G stall speed is called an accelerated stall. In a constant rate turn, load factors increase as the bank angle increases. Pulling back on the pitch control also increases load factors.
An airplane’s stall speed increases in proportion to the square root of the load factor.
Accelerated VS = VS × √(Load Factor)
Example: The load factor in a 60° bank is 2 Gs. The square root of 2 is 1.41, which means that the stall speed increases by 41%. An airplane that has a normal unaccelerated stall speed of 50 knots stalls at approximately 70 knots when subjected to a load of 2 Gs.
Bank | Load Factor | Stall Speed Increase |
0° | 1.0 G | 0% |
30° | 1.15 Gs | 7% |
45° | 1.41 Gs | 19% |
50° | 1.56 Gs | 25% |
60° | 2.0 Gs | 41% |
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. As a result, 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)
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 VA or VO
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
- Note the pitch and power settings for use during the rollout.
- Smoothly and firmly apply aileron and rudder pressure in the direction of the desired turn.
- As the bank angle increases, apply back pressure on the pitch control to maintain level flight. Apply trim if desired.
- Smoothly add power to maintain airspeed.
- 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
- Lead the rollout heading by one-half the number of degrees of the angle of bank (e.g., 50° bank ÷ 2 = 25° lead).
- Simultaneously apply forward pressure to level the pitch attitude and reduce the power back to the entry setting.
- Immediately roll into a turn in the opposite direction, if appropriate.
Exit
- Return to cruise speed, trimming as necessary.
- 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
Risk Examples for Flight Maneuver and Stall Training
Division of Attention Between Aircraft Control and Orientation
- Frequent changes in flight path can cause loss of precise aircraft control; use smooth, coordinated control inputs.
- Fixating the eyes inside or outside the aircraft can lead to a loss of control or orientation; maintain a balanced scan between instruments and outside references.
Collision Hazards During Flight Maneuvers
- High-density training areas increase the likelihood of mid-air collisions; perform clearing turns and make radio calls.
- Busy airways or arrival routes can interfere with IFR operations; track the aircraft’s progress on a chart.
- Abrupt altitude changes during maneuvers increase the likelihood of mid-air collisions; perform clearing turns and make radio calls.
- Distractions while performing maneuvers increase the likelihood of mid-air collisions; minimize flight deck distractions and stay vigilant.
Low-Altitude Maneuvering, Including Stall, Spin, or CFIT
- Power lines, towers, and rapidly rising terrain increase the potential for CFIT; avoid unnecessary maneuvers near the ground.
- Lack of airspeed or altitude awareness can lead to inadvertent CFIT, stall, spin, or loss of control; increase focus and awareness as altitude or airspeed decreases.
Distractions, Task Prioritization, Loss of Situational Awareness, or Disorientation
- Distractions, task prioritization, loss of situational awareness, and disorientation increase the likelihood of errors, delayed or missed actions, and the inability to process information accurately and timely; minimize non-essential activities, follow the “Aviate, Navigate, Communicate” prioritization, and stay focused.
Uncoordinated Flight
- Improper or inadequate control inputs leading to slips or skids can cause uncoordinated or cross-controlled stalls or spins; use smooth control inputs and monitor coordination.
Airman Certification Standards for Steep Turns
References: FAA-S-8081-29, FAA-S-ACS-6, FAA-S-ACS-7, FAA-S-ACS-25
Notes:
- For sport and private pilots, the number of 360° turns is specified by the evaluator. Commercial pilot and flight instructor certification requires two 360° turns in opposite directions.
- Steep turns are not considered as “self-clearing.” A failure to clear the area is subject to disapproval.
Airspeed | Altitude | Bank | Rollout |
---|---|---|---|
±10 KIAS | ±100′ | 45° ±5° (SPT, PVT) 50° ±5° (COM, CFI) | ±10° |