Random 2 Flashcards
Air becomes denser as air pressure increases. True or false?
True.
The higher humidity the lower density. True or false?
True.
Since there are less air molecules for the wings to affect this would mean less lift for the aircraft.
Define drag.
A rearward, retarding force caused by the disruption of airflow by protruding objects on the aircraft. (Eg wing, rotor, fuselage, etc)
Drag opposes thrust. The shape of an aircraft determines the amount of drag produced.
How does the ailerons, elevators and rudder affect aircraft movement?
Aileron: roll
Elevator: pitch
Rudder: yaw
What is “angle of attack” and how does it affect lift?
The angle between the chord line and the relative wind.
As the angle of attack increases so does lift.
What is the “angle of incidence” ?
The angle between the chord and the longitudinal axis of an aircraft. This angle is usually fixed.
What causes lift?
The pressure gradient difference between the upper and lower surfaces of the aero foil.
What does Bernoulli’s principle state?
An increase in the speed of a fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid’s potential energy.
Air is a fluid made up of molecules which are constantly moving. The moving molecules create “air pressure”. True or false?
True
What are the factors affecting lift?
Gravity and mass
Angle at which the aircraft meets the oncoming air (angle of attack)
Size and shape of the wing
Speed the aircraft moves through the air
Density of the air
What is relative wind?
The direction of movement of the atmosphere relative to an aircraft or an aerofoil.
Relative wind in never the same. True or False?
False.
Relative wind is always the same whether the aircraft is in a climb, descent or level flight. Relative wind is always opposite to the flight path.
what is the “camber” and what does it determine ?
The curvature of an airfoils upper or lower surface.
It determines the airfoils thickness and the amount of lift the wing produces as air flows around it.
An aerofoil that is not cambered is called a ..?
Symmetrical aerofoil.
What is a “Stall”?
An aerodynamic condition when smooth airflow over the airplanes wings is disrupted resulting in loss of lift.
