Effects of Controls The Flight Training Manual Section

Effects of Controls The Flight Training Manual - Section 4

Objectives • To operate the primary control surfaces and to experience the feel and observe the first aerodynamic effect on the aircraft in flight. • To operate the primary control surfaces and observe the further (or secondary) aerodynamic effect on the aircraft in flight. • To operate the ancillary controls and to experience the feel and observe the effect on the aircraft in flight.

Principles of Flight • • • Aeroplane Axes Lift Primary Controls Ancillary Controls Inertia

Axes – Lateral Elevator Pitch Up Pitch Down

Axes – Longitudinal Roll Left Ailerons Roll Right Roll Left Longitudinal

Axes – Normal Yaw Right Yaw Left Rudder

Lift – Associated Terminology Chord Line AOA RAF Aerofoil

Lift – Newton’s Third Law • An aerofoil generates lift by exerting a downward force on the air as it flows past. According to Newton's third law, the air must exert an equal and opposite (upward) force on the aerofoil, which is the lift.

Lift – Bernoulli’s Theorem • The sum of energies of a streamlined flow of an ideal fluid remain constant • The faster the velocity, the lower the pressure.

Lift – Bernoulli’s Theorem As air flows over the wing, the increased speed above the wing results in reduced pressure = Lift

Lift – Increase We can increase the Lift by: Increasing the airspeed

Lift – Altering We can alter the Lift by: Changing the Angle of Attack

Lift – Alter We can alter the Lift by: Changing the shape of the wing

Primary Controls

Primary Controls – Elevator Pitch Up Pitch Down Changes Attitude and Airspeed

Primary Controls – Ailerons Roll Left Ailerons Roll Right Roll Left Changes Direction

Primary Controls – Rudder Yaw Right Yaw Left Maintain Balanced Flight

Primary Controls – Slipstream Ailerons are outside the slipstream therefore they are not affected by changes to the slipstream Elevator and Rudder are inside the slipstream therefore they are affected by changes to the slipstream

Primary Controls – Slipstream

Ancillary Controls Trim Throttle Flap

Throttle – Reducing Power High Power Low Power Reduced Slipstream Downwards aerodynamic force on tail plane The couple is unbalanced Reduced Thrust = Nose Down Reduced aerodynamic force on tail plane

Throttle – Increasing Power Low Power High Power Increased Slipstream Downwards aerodynamic force on tail plane The couple is unbalanced Increased aerodynamic force on tail plane Increased Thrust = Nose Up

Trim Used to Relieve Flight Control Pressures Trim after: • Power or speed change • Configuration change (flaps) • Change of CG Trim is your Friend

Flap

Flap Lift & Drag Increase Flaps Down Flaps Up Flap Operating Range VFE and White Arc (C 152 85 kt, PA 38 89 kt) “Lift” Flap – (10º) More Lift than Drag “Drag” Flap – (20º to 30º) Increases Lift but significant increase in Drag Changes: Wing Shape Pitch Attitude and Trim Change

Flap – Pitch Change Low Wing (PA 38) Pitch Down High Wing (C 152) Pitch Up

Inertia Newton’s First Law of Motion “An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force. ” Inertia The resistance an object has to a change in its state of motion. The aircraft will take time to react to control inputs. This must be taken into account when changing the speed or the direction of the aircraft. “ANTICIPATE”

Airmanship Visual Flight Rules Instructor Speak (VFR) • “I have control” • Clear of Cloud • “You have control” • In sight of ground or • “Follow me through” water Main Reference • See & Be Seen • Horizon • Ground Features • North, South, East, West, Airfield

Airmanship Lookout • • • Left to Right 2 sec / 20 90% Outside Always point out aircraft you see Clock Code “Bandits at 10 o’clock high!”

Airmanship – Personal Checklist I’M S. A. F. E • Illness • Medication • Stress • Alcohol (or Drugs) • Fatigue • Eating

Human Factors Lookout: • Limitations • Focus, obstacles • Peripheral (detects movement) Memory: • Information overload • Short-term memory 7 items 2 • Use checklists

Human Factors Stress: • Being busy affects performance and information processing • Become more comfortable with practice Lesson Structure: • Demonstrating different items therefore is an uncoordinated lesson • Future lessons will build on previous ones

Aeroplane Management – Throttle • • Move Forward to Increase Power Move Back to Decrease Power Smooth Movements (0 – Full = 2 sec) Look after the engine

Aeroplane Management – Mixture • • • Changes Fuel/Air ratio Adjust for change in height (air density) Out/Down for “Idle Cut Off” In/Up for “Full Rich” Set full rich for initial training flights

Aeroplane Management – Carb Heat • Used for possible carburettor icing • In/Up for “Off” (Cold) • Out/Down for “On” (Hot)

Aeroplane Management – T’s & P’s Temperatures and Pressures In the “Green” - normal operating range

Aeroplane Management – Flap C 152 Electrical VFE 85 kt White Arc PA 38 Manual VFE 89 kt

Aeroplane Management – Pre-flight Complete details in the Flight Manual

Air Exercise – Attitude flying, by referencing the nose, and the wings - to the horizon

Air Exercise – Aileron When used on their “own” Roll Slip Spiral Descent Yaw

Air Exercise – Rudder When used on it’s “own” less lift more lift less lift Yaw Skid Spiral Descent Roll more lift

Air Exercise – Summary Control Input Primary Effect Further Effect Use Elevator Control Column Rearward Forward Pitch Up Pitch Down Aileron Control Column Left Right Roll Left Roll Right Slip – Yaw Direction Spiral Descent Rudder Pedals Left Right Yaw Left Yaw Right Skid – Roll Balance Spiral Descent Nil Controls are used in the correct sense Movement is relative to the pilot/aircraft Attitude Airspeed

Air Exercise – Airspeed All Controls Affected by Airspeed Increased Airspeed Feel Harder More Responsive Smaller Movements Decreased Airspeed Feel Sluggish Less Responsive Larger Movements

Air Exercise – Slipstream Elevator and Rudder are inside the slipstream therefore they are affected by changes to the slipstream Constant Airspeed Increased power = increased slipstream MORE Effective Decreased power = decreased slipstream less effective Yaw Rudder

Air Exercise – Power To Correct Use Right Rudder Pitch up Increasing Power Yaw Right Yaw Left To Correct Use Left Rudder Decreasing Power Pitch Down

Air Exercise – Trim Used to Relieve Flight Control Pressures Holding forward pressure Trim forward Holding back pressure Trim backwards Trim is your Friend

Air Exercise – Flaps Lowered = Increase in Lift (Balloon) Compensate by changing the attitude of the aircraft when flaps are extended or retracted Sink occurs when Flaps are retracted

Air Exercise – Flap Use of Flap Lowering Flap: • Check Airspeed White Arc VFE: C 152 85 kt, PA 38 89 kt • Adjust the attitude to maintain speed – Trim • Note: Pitch Change, Increased Drag (IAS) Raising Flap: • Check Airspeed Lower the nose slightly to increase speed (1. 2 VS for next configuration) • Arrest sink with slight back pressure when flap is raised.