Vocabulary Design

Question 1

a point(about one quarter of the distance from the leading edge to the trailing edge of an airfoil section)about which the resultant pitching moment of all aerodynamic forces is constant within the working range of angle of attack.

Answer 1

Aerodynamic centre

Question 2

is a chord length in the plane of symmetry along the zero lift line of the wing. It is used as a datum length for calculating pitching moments and moment coefficient.

Answer 2

Aerodynamic mean chord MAC

Question 3

a surface, or combination of high drag surfaces, put out
into the airflow to slow down

Answer 3

Airbrake

Question 4

the angle between the datum line of the aircraftfrom nose to tail, and the chord line of an aerofoil section

Answer 4

Angle of incidence

Question 5

total pressure = static + dynamic pressure, p + q = C

Answer 5

Bernoulli’s Law

Question 6

Shaking and thumping of the aircraft caused by turbulentlumps of agitated air left behind in the wake.

Answer 6

Buffet

Question 7

Motion of the air or water along a curved path. Circulation produces lift.

Answer 7

Circulation

Question 8

the tendency of the air or water to follow a curved surface is called after t

Answer 8

Coanda Effect

Question 9

a term describing the geometry of an airplane, when various elements(flaps, landing gear) making up its shape have been rearranged for subsequent fligt

Answer 9

Configuration

Question 10

the angle subtended between the chord lines of biplane wings, and between wings and stabiliser

Answer 10

Decalage

Question 11

the condition of the relative airflow remote from the aircraft and so not influenced by its presence.

Answer 11

Free stream

Question 12

the vertical distance between the wings of a biplane

Answer 12

Gap

Question 13

the magnitude of the aerodynamic twisting effect exerted at the hinge of a control or flap surface.

Answer 13

Hinge moment

Question 14

tips of the surfaces are raked by cutting them at an angle of the line of flight, making the leading and the trailing edges of different
lengths.

Answer 14

Rake

Question 15

the amount by which one wing of a biplane is set ahead of the other

Answer 15

Stagger

Question 16

twisting of the wing along the span to
decrease the incidence at the tip relative to the root, or to increase the incidence outboard.

Answer 16

Wash in and wash out

Question 17

a measure of work that would be needed to impart kinetic energy of rotation to a body about an axis.

Answer 17

Moment of Inertia

Question 18

a given mixture of air and fuel in the cylinders of a piston can be caused to explode prematurely by a combination of
compression pressure and charge temperature

Answer 18

Anti detonants

Question 19

causes loss of power and mechanical shocks that can cause engine failure.

Answer 19

Detonation

Question 20

is the percentage of iso octane in a blend of is octane and normal heptane which has the same knock characteristics as the fuel being rated.

Answer 20

Octane rating

Question 21

strictly the increase of engine manifold pressure by supercharging

Answer 21

Boost Pressure

Question 22

supply the cylinders with fuel air
mixture

Answer 22

Carburetter and Fuel injector

Question 24

a fan or propeller driven by the engine and
working within a duct to reduce tip losses and noise, thus increasing propulsive efficiency.

Answer 24

Ducted fan or propeller

Question 25

the engine, failure of which gives the most adverse effect on the flying characteristics of the aeroplane relative to the case immediately under consideration

Answer 25

Critical Engine

Question 26

Setting the blades of a stopped propeller at zero angle of attack, so as to reduce drag to the minimum by preventing windmilling

Answer 26

Feathering

Question 27

a lever or knob which the pilot controls the ratio fuel/air for any given throttle setting.

Answer 27

Mixture Control

Question 28

the airflow caused by the propeller alone

Answer 28

Propwash

Question 29

the relative airflow past an aircraft

Answer 29

Slipstream

Question 30

a form of pump which compresses the air supplied to the cylinders, to be mixed with fuel so as to maintain power to higher altitudes.

Answer 30

Supercharger and Turbo(super)charger

Question 31

Free play in the cockpit control i.e., any motion of a control which does not immediately deflect a control surface

Answer 31

Backlash

Question 32

the force a pilot must apply to move a control from a given position.

Answer 32

Breakout Force

Question 33

the tendency of a control surface to move with the changes in the relative wind.

Answer 33

Float or trail

Question 34

the relationship between control surface movement and the movement of the control in the cockpit

Answer 34

Gearing

Question 35

Control horn balances are fitted to aileron, elevator and rudder surfaces, as required, so as to reduce the control surfaces felt by the pilot.

Answer 35

Horn

Question 36

Oscillation of a control surface about its trimmed position

Answer 36

Hunting

Question 37

when a control surface moves to full deflection and it is difficult to centralise it using normal effort

Answer 37

Locking

Question 38

a control is overbalanced when a force must be applied to prevent further deflection.

Answer 38

Overbalance

Question 39

if the deflection of a control produces the required response, then the control is effective.

Answer 39

Control Effectiveness

Question 40

the subjective impression of the pilot to the response of the aircraft to control.

Answer 40

Feel

Question 41

Controls are said to be well harmonised when forces and deflections, and the response of the aircraft to them, are such that the pilot is not aware of having to use too much or too little effort.

Answer 41

Harmonisation

Question 42

responsiveness depends upon rotational inertia about an axis, aerodynamic damping and stability.

Answer 42

Response

Question 43

when it feels as if it is connected to a spring, which must be compressed or extended before the control surface begins to move.

Answer 43

Spongy

Question 44

a regular short period oscillation in yaw and roll

Answer 44

Dutch Roll

Question 45

a high frequency oscillation usually caused by the inter action of aerodynamic forces and the natural frequencies of control surfaces and structure.

Answer 45

Flutter

Question 46

Fairly regular pitching oscillations of low frequency

Answer 46

Porpoising

Question 47

flight with a component of airflow from the side

Answer 47

Sideslip

Question 48

a marked increase in rate of descent with the aeroplane maintaining a more or less constant attitude, increasing the angle of atack

Answer 48

Sinking

Question 49

a lateral and directional oscillation, predominantly in yaw

Answer 49

Snaking

Question 50

the condition in a turn or a pull out such that a push force is needed on the stick to hold constant ‘g’.

Answer 50

Tightening

Question 51

calibrated airspeed is the indicated of the aeroplane , corrected for position and instrument error.

Answer 51

CAS

Question 52

CAS expressed in knots

Answer 52

KCAS

Question 53

outside air temp. is the free air static (ambient) temp.

Answer 53

OAT

Question 54

Actual atmospheric pressure at field elevation.

Answer 54

Station Pressure

Question 55

maximum power permissible for take off

Answer 55

TOP

Question 56

the distance needed to accelerate an aeroplane to a specified speed and , assuming failure of an engine at the instant that speed is attained, to bring the aircraft to a stop.

Answer 56

Accelerate stop distance

Question 57

Airloads on the skin distort the airframe, but the structure is said to be aero elastic if it absorbs loads with out breakage and returns to its original shape when they are removed.

Answer 57

Aero elasticity

Question 58

a technique used mainly to reduce the aero elastic bending of wings.

Answer 58

Bending relief

Question 59

aircraft prepared for service weight: a fully equipped operational airplane, empty for example without crew, fuel or payload

Answer 59

APS weight

Question 60

standard empty weight plus optional equipment.

Answer 60

Basic empty weight

Question 61

weight of a standard aeroplane including unusable fuel, full operating fluids and full oil.

Answer 61

Standard empty weight