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07-B: Power-off

Knowledge

K1: Aerodynamics associated with slow flight in various airplane configuration, including the relationship between angle of attack, airspeed, load factor, power setting, airplane weight and center of gravity, airplane altitude, and yaw effects

  • critical angle of attack

    • the point at which the wing will stall

  • stalls

    • stall properties
      • a wing if and only if the critical angle of attack is exceeded (irrespective of speed, attitude, aircraft type, weight)
      • a wing can be stalled at any airspeed or attitude
      • the smooth airflow over the wing becomes turbulent reducing lift
    • stall speeds
      • V_S0
        • stalling speed = minimum staedy flight spped = minimum controllable airspeed
        • in landing configuration
      • increases with
        • aircraft weight
        • turbulence
        • turns
        • maneuvering
      • decreases with
        • flaps
      • indicated stall speed is unaffected by altitude
        • the airspeed indicator is a lift measurement device

K2: Stall characteristics as they relate to airplane design, and recognition impending stall and full stall indications in sight, sound, or feel

K3: Factors and situations that can lead to a power-off stall and actions that can be taken to prevent it

  • prior to starting each maneuver,
    • we need to visually scan the entire area for collision avoidance
  • a stall due to pilot inattentiveness with full power occurs most likely during takeoff and climb

K4: Fundamentals of stall recovery

  • T-tail aircraft can be more difficult to recover due to loss of elevator effectiveness due to blanketing
  • experience less or no elevator buffetting due to blanketing

1) clear the area 2) climb to at least 1500 AGL

get into landing configuration 2) power 1500 RPM, carb heat on 3) below 110, flaps 10 4) find and keep approach speed (65 knots) 5) in the white arc, below 85, full flaps 1) power to idle 2) then keep downward attitude for 65 knots for approach simulation

induce stall 6) after three seconds, pull up the nose to the horizon, and don't let the nose come down 7) more back-pressure if it takes too long 8) call out stall horn

recover 9) release backpressure 10) full power, carb heat off 11) right rudder 12) climb back at vx or vy 1) 44 knots, flaps 20 2) positive rate of climb, flaps 10 3) positive rate of climb, flaps clean

  • why does it take time to until control inputs have an affect
    • kinetic energy needs to be transfered from the the aircraft to the air atom
    • every air atom can only take so much kinetic energy
    • need to see many air atoms to transfer much kinetic energy