Forces/Aerofoils Flashcards
What are the forces acting on an aircraft in flight?
Thrust, Lift, Weight, Drag
If thrust equals drag and lift equals weight then…..?
….the aircraft is in equilibrium.
What is the relationship of thrust and drag when and aircraft accelerates?
Thrust is greater than drag.
How does an aircraft maintain altitude during a turn?
By increasing the AoA or speed to increase lift.
What produces the maximum glide range?
The maximum lift-drag ratio, obtained by the aircraft being flown at it’s optimal AoA and corresponding min drag speed.
What is the effect of weight on the glide range?
Weight has no effect on the glide range of an aircraft in nil wind conditions. A heavy aircraft will descend at a faster rate but if it maintains the correct lift-drag ratio by maintaining the correct AoA, the range maintains the same.
What is rate of climb/descent?
RoC/RoD is the vertical component of the velocity of an aircraft and determines the time it will take to either climb or descend from a given height. It is normally expressed in terms of feet per minute.
What is the effect of weight on rate of descent?
The heavier the aircraft, the greater the RoD. This is because a heavy aircraft needs to fly faster to produce more lift at a given AoA to counter the extra weight.
What is an aerofoil?
An aerofoil is an object that when presented to an air stream at a given AoA it will produce a certain amount of lift. An aerodynamic aerofoil will try to produce the most amount of lift with least amount of drag.
What is an aerofoil chord line?
The chord line is a straight line running from the leading edge to the trailing edge of the aerofoil.
What is the mean chord line?
The mean chord line is the wing area divided by the wing span.
What is the mean camberline?
The mean camberline is a line from the leading edge to the trailing edge of equidistance on the upper and lower surface of an aerofoil.
What is the angle of incidence?
The angle of incidence is the angle between the aerofoil’s chord line and the aircraft’s longitudinal datum. It is a fixed angle for a wing but may be variable for a tailplane. (rigging incidence)
What is an AoA?
The AoA is the angle between the chord line of an aerofoil and the relative airflow.
What is washout on a wing?
Washout is a decrease in the angle of incidence from wing root to wing tip. This compensates for the early stall due to the higher levels of loading experienced at the wing tips.
