Exercise 4 EFFECTS OF CONTROLS 1 CFS Gliding Examiners © 2008

To select the datum attitude using co-ordinated controls AIM To select the datum attitude using co-ordinated controls

AIRMANSHIP Lookout Handing over and taking over control Following through and relaxing

LOOKOUT Lookout If you see an aircraft before your instructor does, use the Clock Code to tell him where it is…

LOOKOUT The Clock Code Imagine you are at the centre of the dial and 12 o’clock is straight ahead

“Aircraft left 11 o'clock high”

“Aircraft right one o'clock level”

TAKING OVER CONTROL If your instructor wishes to give you control, he will say: “You have control” Put your hands and feet lightly on the controls and say: What do you do? “I have control, sir”

HAND TAK ING OVER CONTROL If your instructor wishes to take over control, he will say: “I have control” Take your hands and feet off the controls and say: What do you do? “You have control, sir”

FOLLOWING THROUGH If your instructor wants you to follow through, he will say: “Follow me through” Put your hands and feet lightly on the controls and say: What do you do? “Following through, sir”

RELAXING If your instructor wants you to relax, he will say: “Relax” Take your hands and feet off the controls and say: What do you do? “Relaxed, sir”

THE DATUM ATTITUDE THE DATUM ATTITUDE

Note distance below horizon THE DATUM ATTITUDE Note distance below horizon

Instrument panel is parallel to horizon THE DATUM ATTITUDE Instrument panel is parallel to horizon

Here are some more attitudes you will see… THE DATUM ATTITUDE Here are some more attitudes you will see… Airspeed is stable

THE BANKED ATTITUDE

THE APPROACH ATTITUDE THE BANKED ATTITUDE

STABILITY STABILITY The aircraft is stable and will maintain the attitude with no control input needed

AIRCRAFT AXES AIRCRAFT AXES Lateral axis

The aircraft PITCHES about the lateral axis AIRCRAFT AXES Lateral axis The aircraft PITCHES about the lateral axis

AIRCRAFT AXES Longitudinal axis

The aircraft ROLLS about the longitudinal axis AIRCRAFT AXES Longitudinal axis The aircraft ROLLS about the longitudinal axis

AIRCRAFT AXES Vertical axis

The aircraft YAWS about the vertical axis AIRCRAFT AXES The aircraft YAWS about the vertical axis Vertical axis

PRIMARY EFFECTS OF THE CONTROLS ELEVATORS

ELEVATORS ELEVATORS

ELEVATORS When you move the control column forward… …the elevators move down

ELEVATORS The aircraft starts to pitch nose down…

ELEVATORS …and continues to pitch until the control column is returned to the neutral position

ELEVATORS Likewise, if you move the control column back… …the elevators move up… …and the aircraft pitches nose up until you return the control column to the neutral position

PRIMARY EFFECTS OF THE CONTROLS AILERONS

AILERONS AILERONS

AILERONS When you move the control column to the right… …the left aileron moves down and the right aileron moves up

AILERONS The aircraft starts to roll to the right… …and continues to roll until the control column is returned to the neutral position

AILERONS Likewise, if you move the control column to the left… …the left aileron moves up and the right aileron moves down … …and the aircraft rolls to the left until you return the control column to the neutral position

PRIMARY EFFECTS OF THE CONTROLS RUDDER

RUDDER RUDDER

RUDDER When you push the right rudder pedal forwards… …the rudder moves to the right…

RUDDER …and the aircraft yaws to the right

RUDDER As the aircraft yaws right, the slip ball moves left to indicate unbalanced flight

RUDDER To restore balanced flight, push the left pedal forwards until the slip ball is central

If the ball is outside the ‘goalposts’… …push the appropriate pedal forwards (right pedal if the ball is out to the right)… …until the ball is back in the centre In balanced flight, note that the rudder pedals are not necessarily centred

EFFECTS OF CONTROLS IN A BANKED ATTITUDE

EFFECTS OF CONTROLS IN A BANKED ATTITUDE An aircraft always manoeuvres about its axes… Vertical axis If the aircraft is banked, so are its axes Lateral axis

EFFECTS OF CONTROLS IN A BANKED ATTITUDE So in a level attitude, this is pitch…

EFFECTS OF CONTROLS IN A BANKED ATTITUDE So in a level attitude, this is pitch… …and this is yaw

EFFECTS OF CONTROLS IN A BANKED ATTITUDE But in a banked attitude, this is pitch…

EFFECTS OF CONTROLS IN A BANKED ATTITUDE In a banked attitude, this is pitch… …and this is yaw

PROPORTIONAL RESPONSE The rate at which the aircraft responds depends on how much you deflect the controls

PROPORTIONAL RESPONSE So if you deflect the ailerons a small amount…

PROPORTIONAL RESPONSE …the aircraft rolls slowly

PROPORTIONAL RESPONSE And if you deflect the ailerons a large amount…

PROPORTIONAL RESPONSE …the aircraft rolls quickly

PROPORTIONAL RESPONSE The same applies to the elevator and rudder: Remember, the rate at which the aircraft responds depends on how much you deflect the controls, not on how quickly you deflect them

The rate at which the aircraft responds also depends on the airspeed EFFECT OF SPEED EFFECT OF SPEED The rate at which the aircraft responds also depends on the airspeed

sloppy sluggish EFFECT OF SPEED For the same control deflection: At low speed, controls feel and response is sloppy sluggish At high speed, controls feel and response is firm crisp

ADVERSE YAW ADVERSE YAW

ADVERSE YAW When you deflect the ailerons… …lift on this wing increases… …and lift on this wing reduces

ADVERSE YAW …causing the aircraft to roll

…so the aircraft also yaws ADVERSE YAW However, more lift means more drag… …so the aircraft also yaws

ADVERSE YAW Because the aircraft yaws left when you want to roll right, it is called ADVERSE YAW… …and can be prevented by applying rudder in the same direction as aileron

CO-ORDINATED CONTROLS ADVERSE YAW So whenever you want to roll, you must apply rudder at the same time as you apply the ailerons… …in the same direction… …and by just the right amount to prevent adverse yaw This is called CO-ORDINATED CONTROLS

SELECTING THE DATUM ATTITUDE To select the datum attitude… SELECTING THE DATUM ATTITUDE

SELECTING THE DATUM ATTITUDE To select the datum attitude… …first roll wings level using co-ordinated controls

SELECTING THE DATUM ATTITUDE To select the datum attitude… …first roll wings level using co-ordinated controls then pitch to the datum attitude using elevator

? THE END Any Questions

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