Teaching and Learning Flying - Airplane Instrument Rating

Steep Turns

DEFINITION

SAFETY FACTORS

• Above 1,500 feet AGL
• Lights on
• CLEAR area with two 90° turns, left and right
• Maneuvering speed, V_A, (N6209T: approximately 105 knots)
• Less than 60° bank
• Student under hood; instructor watching for other traffic
• Good, efficient instrument scan, interpretation, and control technique avoids overbanking and rapid altitude loss

TOLERANCES

• Private Pilot PTS, V. Steep Turns
  • Exhibits knowledge of related elements
  • POH recommended or safe airspeed not to exceed < V_A
  • Coordinated 360° turn(s)
  • Bank 45° +/-5°
  • Divides attention between control and orientation
  • Rollout on entry heading +/-10°
  • Altitude +/-100 feet
  • Airspeed +/- 10 knots
• Commercial PTS, V A, Steep Turns: as Private except:
  • Bank at least 50° +/-5°
  • 360° turn followed by one in opposite direction

OBJECTIVES

To develop smoothness, coordination, orientation, division of attention, and instrument scan, interpretation and aircraft control techniques while executing high performance turns in simulated IMC

PROCEDURES

PREFLIGHT
• Discuss definition, objectives, tolerances, and elements of steep power turns in IMC
• Relationship of bank angle, load factor, and stalling speed
  • Load factor increases rapidly as bank angle exceeds 45°
  • At 60° bank, load factor is 2 G's
  • Stall speed increases in proportion to the square root of the load factor
• Overbanking tendency
  • Bank angle greater than 45°: relative excess lift on outside wing overcomes dihedral and keel effects responsible for positive static roll stability in shallow bank turns
  • Negative static stability
  • Requirement for opposite aileron pressure
• Torque effect in right and left turns
  Pitch higher + power increase = increase in left turning tendency
• Selection of a suitable altitude
  Above 1,500 feet AGL
• Orientation, division of attention, and planning
  Good, efficient instrument scan, interpretation, and control technique avoids overbanking and rapid altitude loss
• Appropriate power setting and airspeed prior to entry
  V_A, (N6209T: MP 19 in, 105 knots)
• Coordination of flight controls
• Differential wing drag
  • Wing with lowered aileron has more drag
  • May cause adverse yaw
  • Role of Frise type ailerons (N6209T)
INFLIGHT
• Demonstrate the steep power turn, 360°
  1. Lights on and CLEAR area
  2. Note heading
  3. Smooth, coordinated bank to 50 +/-5°
  4. After bank exceeds 30°, pitch up and add 1" of MP
  5. Hold pitch on AI
  6. Correct small altitude changes with small bank changes
  7. Lead rollout approximately 30°
  8. Smooth, coordinated rollout while releasing back elevator pressure and reducing MP 1"
• Coach student practice in both directions
POSTFLIGHT
Critique student performance

COMMON ERRORS

• Improper pitch, bank, and power coordination during entry and rollout
  • Too much pitch up too soon on entry
  • Holding back pressure during rollout and climbing
• Uncoordinated use of flight controls
  Especially slipping in right turns
• Inappropriate control applications
• Improper technique in correcting altitude deviations
• Loss of orientation
  Forgetting initial heading
• Excessive deviation from desired heading during rollout
  • Lack of planning
  • Lead rollout by approximately 30°

Instrument Flying Handbook FAA-H-8083-15

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