Lesson Plan
Performance Maneuvers: Steep Turns
Purpose
The steep turn also helps pilots become familiar with how the aircraft feels and responds when executing a maneuver with a load factor that's not used in normal flight operations.
The objective of the steep turn is to develop a pilot's skill in flight control smoothness and coordination, an awareness of the airplane's orientation to outside references, division of attention between flight control application, and the constant need to scan for hazards.
Elements
Single or multiple turns: Steep turns consist of single to multiple 360° to 720° turns, in either or both directions, using a bank angle between 45° to 60°.
Aerodynamic factors: When performing steep turns, pilots will be exposed to:
- Higher load factors
- The airplane's inherent overbanking tendency
- The loss of vertical component of lift when the wings are steeply banked
- The need for substantial pitch control pressures
- The need for additional power to maintain altitude and airspeed during the turn.
Vertical and horizontal lift: When an airplane is banked, the total lift is divided between the vertical component of lift and the horizontal component of lift.
Increase AOA to maintain altitude: In order to maintain altitude, the pilot must increase the wing's angle of attack (AOA) to ensure that the vertical component of lift is sufficient to maintain altitude.
Increased load factor: The load factor is the vector resultant of gravity and centrifugal force.
Total lift increases: Total lift must increase substantially to balance the load factor or G-force (G).
- In a level altitude, 45° banked turn, the resulting load factor is 1.4.
- In a level altitude, 60° banked turn, the resulting load factor is 2.0, which effectively doubles the airplane's weight.
- Load factors increase dramatically beyond 60° of bank.
Load factor is predictable: Regardless of airplane or airspeed, the same load factor will always be produced for any given bank angle in a level altitude turn.
Maneuvering speed: Steep turns should be performed at an airspeed that does not exceed the airplanes design maneuvering speed (Va) or the manufacturer's recommended speed.
Max rate, min radius: Maximum turning performance is accomplished when an airplane has both a fast rate of turn and minimum radius of turn.
- This is accomplished with a combination of airspeed and angle of bank.
- Each airplane's turning performance is limited by structural and aerodynamic design, as well as available power.
Limiting load factor: 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, stalling speed increases.
- As the bank angle increases in level flight, the margin between stalling speed and maneuvering speed decreases.
Stall speed increases exponentially: In a bank, stall speed increases at the square root of the load factor.
Overbanking tendency: In a steep turn, the airplane will exhibit overbanking tendency.
- In shallow banks, the airplane exhibits positive or neutral stability about the longitudinal axis.
- As the bank angle steepens, the airplane will continue rolling in the direction of the bank unless opposite aileron pressure is applied.
Left-turning tendencies: In a steep turn, various left turning tendencies, such as P-factor, require coordination of rudder and aileron.
Turn entry: To begin a steep turn:
- Identify a distant reference (such as a mountain peak or road) to assess when to begin rollout from the turn.
- Establish design maneuvering speed (Va) or the manufacturer's recommended entry speed.
- Smoothly roll in to the the desired bank angle. (For private pilots, the certification standard is 45¡ of bank.)
- As the airplane rolls in to the bank, apply elevator back-pressure to increase angle of attack. (The higher AOA will create more drag, which will require more power to overcome.)
Maintaining the turn: Elevator trim and power can be applied as the maneuver is entered, which will minimize control pressure inputs.
Altitude deviations: Deviations are common when performing steep turns.
- A pilot who observes both the nose and the wings relative to the horizon is likely able to maintain altitude within performance standards.
- If altitude varies, a slight increase or decrease in bank angle can be used to return to the selected altitude.
- Elevator back-pressure also can be used, but it is not as effective.
Rolling out: Prior to reaching the terminating heading, begin the rollout at half the number of degrees of bank. For a 45° banked turn, the pilot can begin the rollout 20-30° before the selected heading. As the maneuver is completed, trim and power must be restored for level flight.
Procedure
- Identify an external reference.
- Establish maneuvering speed (Va) or recommended entry speed.
- Smoothly roll in to the desired bank angle.
- As the airplane rolls in to the bank, apply elevator back-pressure.
- Apply elevator trim and power as the maneuver is entered.
- Correct altitude deviations.
- Begin rollout prior to reaching the terminating heading (half the number of degrees of bank.
- Restore trim and power for level flight.
Common Errors
Common errors when performing steep turns include:
- Not clearing the area
- Inadequate pitch control on entry or rollout
- Gaining altitude or losing altitude
- 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 instrument rather than visual references
- Failure to scan for other traffic during the maneuver
- Attempts to start recovery prematurely
- Failure to stop the turn on designated heading
Completion Standards
Private Pilot Airmen Certification Standards (ACS)
- Establish the manufacturer's recommended airspeed or, if not stated, a safe airspeed not to exceed Va.
- Roll into a coordinated 360° steep turn with approximately a 45° bank.
- Perform the Task in the opposite direction, as specified by evaluator.
- Maintain the entry altitude ±100 feet, airspeed ±10 knots, bank ±5°; and roll out on the entry heading, ±10°.
Commercial Pilot & Flight Instructor Airmen Certification Standards (ACS)
- Establish the manufacturer's recommended airspeed or, if not stated, a safe airspeed not to exceed Va.
- Roll into a coordinated 360° steep turn with approximately a 50° bank.
- Perform the Task in the opposite direction.
- Maintain the entry altitude ±100 feet, airspeed ±10 knots, bank ±5° and roll out on the entry heading, ±10°.
More Details
More details are available in the Airplane Flying Handbook
Lesson Plan Checklist
Steep Turns