Aerodynamics 1 Flashcards
What are the three types of motion an aircraft is capable of?
Pitch
Roll
Yaw
What are three axis of motion that an aircraft move about?
Lateral axis - pitch
Longitudinal axis - roll
Normal axis (vertical axis) - yaw
What are the 3 primary flight controls of an aircraft?
Elevator - lateral axis - pitch
Ailerons - longitudinal axis - roll
Rudder - normal axis - yaw
What is the common point on an aircraft where all three axis intersect?
Centre of Gravity (CoG)
The elevator(s) initiates or prevents which motion/ action?
Pitching - nose up/ nose down attitude
The aileron(s) initiate or prevent which motion (action)?
Rolling
Changes in aircraft attitude are assessed from where?
The top of the instrument panel
What is the outcome of pulling back on the control column?
Pitch Up / Nose Up / Climb
Elevators deflect upward and consequently the airflow is deflected upward which imposes a downward force on the tail.
What is the outcome of pushing forward on the control column?
Pitch Down / Nose Down / Descend
Elevators deflect downward and consequently the airflow is deflected downward which imposes an upwards force on the tail
What is the outcome of turning the control column right?
Turn right / bank right
The right aileron deflects upward whilst the left aileron deflects downward
If an aileron is deflected downward, which direction will the aircraft turn/ bank?
Turn/ bank toward the opposite wing side
What is the outcome of turning the control column to the left?
Turn left / bank left
The left aileron deflects upward whilst the right aileron deflects downward
The rudders are connected to which control instruments?
The pedals
What is the outcome of pressing the left pedal forward/ in?
Yaw to the left
The rudder is deflected to the left, airflow passing over the rudder deflects to the left which pushes the tail to the right
What is the outcome of pressing the right pedal forward/ in?
Yaw to the right
The rudder is deflected to the right, airflow passing over the rudder deflects to the right which pushes the tail to the left
What is a secondary/ further effect of a roll?
Yaw in the direction of the turn/ bank
What is a secondary / further effect of a yaw?
A roll in the direction of the yaw
What is a dangerous consequence of the roll-yaw relationship?
A spiral dive
How can you recover from a spiral dive?
- Reduce power
- Gently level the wings
- Gently nose up the attitude
- Reapply power
When rolling and yawing to the left, which wing will cover a greater distance and at greater speed?
The right wing (outside wing)
When rolling and yawing to the right, which wing will cover a greater distance and at greater speed?
The left wing (outside wing)
What 3 factors determine the strength and effectiveness of a control input?
- Area of control surface
- The angle at which the control surface is deflected
- The speed of the passing airflow
What are the only 2 factors/ variables that a pilot has control over with regards to a control input?
- Deflection of the control surface
- Speed of the aircraft - speed of airflow passing over the control surface
A pilot can obviously not change the area of the control surface
What is the special effect produced when climbing with high engine power and low forward speed?
A propeller slipstream
Which 2 controls become more effective when exposed to a propeller slipstream?
The elevators and the rudder
The ailerons are outside the influence of the propeller slipstream
When operating at lower speed, will the pilot feel greater or lesser resistance on the controls?
Greater resistance
When operating at higher speed, will the pilot feel greater or lesser resistance on the controls?
Lesser
Is a larger or smaller degree of deflection of the control surface(s) required when operating at low air speeds to achieve a particular pitch, roll or yaw?
Larger
Is a larger or smaller degree of deflection of the control surface(s) required when operating at high air speeds to achieve a particular pitch, roll or yaw?
Smaller
In aviation, what unit of measurement to express speed?
Kts/ hr
knots per hour = nautical miles per hours
For the purpose of expressing runway dimensions and meteorological visibility, what unit of measurement is used?
m or kms
Metres of kilometres
1 nautical mile (1nm) is equivalent to what?
1 knot
1 minute of latitude
1.85km / 1852m
6080ft
What is the atmospheric pressure at sea level?
- 2 Hpa
- 92 inch/hg
- 00 mm/Hg
- 7 lbs/ inch^2
What is the conversion for Temp degrees C and Temp degrees F?
Celsius = Subtract 32 and multiply by 0.555
F = Multiply by 1.8 and add 32
What is the conversion for weight/ mass?
Kgs = Lbs divide 2.2 Lbs = kgs multiply 2.2
What is the conversion for volume?
Litres = US Gallons x 3.8
US Gallons = Litres divide 3.8
Sustained level flight is possible due to a force that is equal and opposite to the weight of the aircraft. What is this force referred to as?
Lift
If the force of lift changes to become less that than weight of the aircraft, will the aircraft climb, descend or remain in level flight?
The aircraft will descend
Is the direction of the relative airflow always equal to or opposite to the direction of the motion?
Relative airflow is always opposite to the motion of the aircraft
Is relative airflow equal to the IAS, GAS or TAS?
Relative airflow is always equal to the aircraft’s True Airspeed (TAS)
On an aerofoil, the straight line joining the leading and trailing edge is called what?
The Chord Line
The angle formed between the chord line of an aerofoil (wing) and the relative airflow is referred to as what?
The Angle of Attack (AoA)
True or False - The mean camber line is an equidistant line drawn from the leading edge to the trailing edge of an aerofoil (wing)?
True
Does the maximum camber on an aerofoil (wing) occur at the point of greatest or least separation between the mean camber line and the chord line?
The point of greatest separation
How does lift and drag act in relation to relative airflow?
Lift acts at a right angle to the direction of the relative airflow.
Drag acts parallel to the direction of the relative airflow.
What is the force that is a resultant of lift and drag?
Total Reaction
What is the name of the point on the aerofoil (wing) where all forces are evenly distributed?
The Centre of Pressure (CoP)
Is the CoP a fixed or moving point on the aerofoil?
The CoP moves in response to a changing AoA
During normal flight, does the CoP move toward the leading edge or toward the trailing edge as AoA is increased?
The CoP moves toward the leading edge as AoA is increased
What is the name of the angle produced on an aerofoil (wing) whereby the maximum possible lift is produced for a given airspeed?
The Critical or Stalling Angle
What happens to the airflow at angles beyond the critical or stalling angle?
The airflow is no longer smooth. More drag and less lift is produced.
To maintain level flight at high speed, can the required lift be produced with a high or low AoA?
A low AoA
To maintain level flight at low speed, can the required lift be produced with a high or low AoA?
A high AoA
With increasing air speed, will both lift and drag increase?
Yes, both lift and drag will increase.
What is the name given to the speed when a pilot has no option but to apply the critical/ stalling AoA to maintain a given amount of lift at low airspeeds?
The Stalling Speed
What will occur if a pilot applies an AoA greater than the Critical/ Stalling Angle at a given airspeed?
The aircraft will stall
How do you recover from a stall?
- Apply forward control column to pitch nose down / reduce AoA
- Level the wings
- Increase power as required
- Return to safe flight path
The magnitude of the total reaction on an aerofoil depends upon what?
- The AoA
2. The speed of the relative airflow
Once the stalling angle has been reached, any increase in the AoA will result in what?
Less lift and more drag
For any given airspeed, the stalling angle is the angle at which what occurs to lift?
Lift reaches its maximum
