Ex. 11 – Slow Flight What’s this plane’s AoA? Can’t tell untill you know which way it is going! This plane is actually on a “high alpha” pass – flight at high angle of attack and low airspeed. This is what we’ll explore today (though not quite to the same angle). Ex. 11 - Slow Flight

OBJECTIVE What you will learn: To recognize the signs of slow flight (flight at airspeeds between maximum endurance and stall) To safely maintain control of the aircraft in slow flight, in a variety of configurations To recover to normal airspeeds with minimal loss of altitude. Ex. 11 - Slow Flight

What’s so bad about that? MOTIVATION Why learn this: To know what entry into slow flight feels like, to avoid accidentally entering it If slow flight is inadvertently entered, to be able to recover safely To become a better and more confident pilot. What’s so bad about that? Ex. 11 - Slow Flight

LINKS Links: Climbs, descents and flight at best endurance speed provided you with a chance to fly at reduced airspeeds You learned how changes in power and flap settings affect the flight You have been practicing good habits lookout carb heat check controlling yaw. Ex. 11 - Slow Flight

Let’s see how much you already know: BACKGROUND KNOWLEDGE - TKT Let’s see how much you already know: What are the two types of drag, and how do they vary with airspeed and angle of attack? What effect do flaps have on lift, drag and visibility? How responsive are the control surfaces when the airplane is slowed down to best endurance airspeed? Sketch the power curve (power required to maintain level flight vs. airspeed) and mark best endurance airspeed on it. Ex. 11 - Slow Flight

Theories and Definitions: THEORIES & DEFINITIONS Theories and Definitions: The Power Curve Yaw in Slow Flight Flaps in Slow Flight. Ex. 11 - Slow Flight

The Power Curve SLOW FLIGHT THEORIES & DEFINITIONS The Power Curve Minimum power is required for level flight at airspeed for best __________________________________ Slowing down further while maintaining altitude will require an increase in ______________________ Slow flight is flight between the airspeed for best endurance and stall speed. “Back side” of power curve Lower airspeeds require more power “Front side” of power curve Lower airspeeds require less power endurance Power available power SLOW FLIGHT Ex. 11 - Slow Flight

Yaw in Slow Flight ASYMMETRIC THRUST SLIPSTREAM TORQUE THEORIES & DEFINITIONS Yaw in Slow Flight SLIPSTREAM ASYMMETRIC THRUST Which rudder will you need in slow flight? slipstream pushes tail to the right plane wants to yaw to the left at high angles of attack, down-going blade has more “bite” and creates more thrust left-yawing tendency TORQUE GYROSCOPIC PRECESSION SLOW FLIGHT reaction to prop rotation causes roll to the left pilot corrects with right aileron, causes adverse yaw to the left spinning propeller acts as a gyroscope raising nose causes right-yawing tendency Ex. 11 - Slow Flight

Flaps in Slow Flight ADVANTAGES OF FLAPS More lift THEORIES & DEFINITIONS Flaps in Slow Flight What effect do flaps have on lift? Drag? Visibility? ADVANTAGES OF FLAPS More lift stall speed reduced More nose-down attitude better forward visibility better engine cooling Ex. 11 - Slow Flight

Procedures HASEL Check Slow Flight Entry During Recovery. PROCEDURES Ex. 11 - Slow Flight

Height Area Security Engine Lookout HASEL Check 2000’ AGL PROCEDURES HASEL Check Height Area Security Engine Lookout 2000’ AGL In your practice area, what is this ASL? not over built-up area harnesses, doors and windows secure baggage strapped down/stowed away “Downwind” Check oil temperature and pressure in the green primer in and locked, master on, mags on both circuit breakers in, ammeter needle right, light off carb heat hot, mixture rich fuel on, gauges show fuel flaps up brake pressure - This is a good time to look at a map, talk with your instructor about how to determine ground elevation, read symbols (towers etc.), MEF… - Consider different scenarios (you turned and are now over a town, etc.) - Keep turns gentle-medium/rate one two 90o turns or one 180o turn - MINIMUM. Ex. 11 - Slow Flight

How will this affect airspeed and altitude? PROCEDURES Slow Flight: Entry HASEL check Reduce power to ~1600 rpm Maintain altitude with elevators Control yaw with rudder Flaps to 20o once airspeed in the white arc Once flight at best endurance airspeed is established, raise the nose Add power to maintain altitude Retrim for new airspeed. How will this affect airspeed and altitude? Ex. 11 - Slow Flight

Slow Flight: During Keep good look-out PROCEDURES Slow Flight: During Keep good look-out Maintain altitude with ___________________ Maintain airspeed with ___________________ Maintain heading with _______________________________________ Control yaw with ___________________ How does slow flight affect your visibility? power elevators How will control responsiveness be affected by slow flight? ailerons + rudder rudder. Ex. 11 - Slow Flight

Slow Flight: Recovery Keep good look-out Full power Carb heat cold PROCEDURES Slow Flight: Recovery Keep good look-out Full power Carb heat cold Maintain altitude with elevators (forward pressure) Control yaw with rudder Flaps up in stages Once back to normal cruise airspeed, reduce power back to cruise Retrim. Ex. 11 - Slow Flight

Considerations Control Responses Stall controls are “sluggish” and “mushy” (one of slow flight signs) ailerons are affected the most elevator and rudder remain relatively effective due to propeller slipstream be prepared for a lot of adverse yaw due to propeller effects and aileron drag Stall at a certain airspeed the airplane will reach a critical angle of attack at which it will no longer be controllable and will start descending rapidly stall entry and recovery will be practiced in the next lesson. Ex. 11 - Slow Flight

SAFETY Good look-out is crucial – visibility is reduced in slow flight Avoid practicing slow flight for prolonged periods of time – engine may overheat Max bank in slow flight = 30o Careful control of airspeed: you’re on the edge of stall! Yaw control is critical: what can stalling uncoordinated lead to? Why? Ex. 11 - Slow Flight

CONCLUSION Conclusion Practicing slow flight will improve your confidence and piloting skills, and help prepare you for mastering take-offs and landings Next lesson: we will slow the plane down even more – to the point of the stall! Read for next lesson: Ex. 12, Stalls QUESTIONS? Ex. 11 - Slow Flight