Ex. 11 - Slow Flight

Ex. 11 – Slow Flight

Ex. 11 - Slow Flight

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.

OBJECTIVE

Ex. 11 - Slow Flight

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.

MOTIVATION

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:Q What are the two types of drag, and how do they vary

with airspeed and angle of attack?

Q What effect do flaps have on lift, drag and visibility?

Q How responsive are the control surfaces when the airplane is slowed down to best endurance airspeed?

Q Sketch the power curve (power required to maintain level flight vs. airspeed) and mark best endurance airspeed on it.

BACKGROUND KNOWLEDGE - TKT

Ex. 11 - Slow Flight

Theories and Definitions:

The Power Curve

Yaw in Slow Flight

Flaps in Slow Flight.

THEORIES & DEFINITIONS

Ex. 11 - Slow Flight

The Power CurveTHEORIES & DEFINITIONS

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 curveLower airspeeds require more power

“Front side” of power curveLower airspeeds require less power

SL

OW

FL

IGH

Tendurance

power

Powera

vailable

Ex. 11 - Slow Flight

Yaw in Slow FlightTHEORIES & DEFINITIONS

SLIPSTREAM ASYMMETRIC THRUST

GYROSCOPIC PRECESSIONTORQUE

• slipstream pushes tail to the right• plane wants to yaw to the left

• spinning propeller acts as a gyroscope• raising nose causes right-yawing tendency

• at high angles of attack, down-going blade has more “bite” and creates more thrust

• left-yawing tendency

• reaction to prop rotation causes roll to the left• pilot corrects with right aileron, causes adverse

yaw to the left

SLOWFLIGHT

Which rudder will you need in slow flight?

Ex. 11 - Slow Flight

Flaps in Slow FlightTHEORIES & DEFINITIONS

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

HASEL CheckPROCEDURES

Height

Area

Security

Engine

Lookout

• 2000’ AGL

• 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

• two 90o turns or one 180o turn - MINIMUM.

In your practice area, what is this ASL?

Ex. 11 - Slow Flight

Slow Flight: EntryPROCEDURES

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

Control yaw with rudder

Retrim for new airspeed.

How will this affect airspeed and altitude?

Ex. 11 - Slow Flight

Slow Flight: DuringPROCEDURES

Keep good look-out

Maintain altitude with ___________________

Maintain airspeed with ___________________

Maintain heading with _______________________________________

Control yaw with ___________________

How does slow flight affect your visibility?

elevators

power

ailerons + rudder

How will control responsiveness be affected by slow flight?

rudder.

Ex. 11 - Slow Flight

Slow Flight: RecoveryPROCEDURES

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

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.

CONSIDERATIONS

Ex. 11 - Slow Flight

SAFETYSAFETY

! 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

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

CONCLUSION

QUESTIONS?