Climbing and Descending Flashcards
What are the forces in a climb? (8 forces 1 explanation)
(W) - weight acting from the CoG towards the centre of the earth
(D) - drag, acting in line with the relative airflow opposing motion
R1 - resultant, which is these two vectors added together
R2 - equal and opposite to R1, made up of two components Lift and thrust
(L) - Lift acting 90 degrees to RAF
(T) - Thrust, acting in line with the RAF in the direction of motion.
R2 is bigger than R1 so components of W1 and RCW are added for balance
W1 - seen on cars on hills and is the component of weight acting to hold the car onto the hill
RCW - component of weight acting to pull the car rearwards down the hill.
what is Vy?
known as the best rate of climb and this gives the greatest gain in height for a given amount of time.
what is Vx?
the best angle of climb or the greatest gain in height for a given distance across the ground.
when is the best rate of climb normally used?
when there are no obstacles seeing as it will allow the aircraft to climb to the required altitude sooner.
where is Vy found?
found where the greatest surplus of horsepower is available over the horsepower required for straight and level flight.
on the graph, its found where the greatest gap is formed between the two curves.
Where is Vx found?
found where the greatest surplus of thrust is available over the thrust required.
on the graph, it’s found just before the minimum thrust required point because they’ll be more thrust available so the gap between thrust available and thrust required is greater and so the angle of climb will be greater.
What is Vc? and what will this allow you to do?
cruise climb. fly faster for a relatively small loss of performance.
what are the factors affecting climb?
weight
wind
flaps
how does weight affect climb?
the more weight means the aircraft will have reduced climb performance and for the same distance will not climb as high.
how does wind affect climb?
the aircraft would gain the same amount of height in the same amount of time, however, because of the headwind reducing the ground speed it wouldn’t travel as far along the ground.
so the rate of climb remains unchanged but the angle of climb increases.
how does flap affect climb?
lowering flaps causes an increase in drag, meaning more power will be required to overcome that drag.
the surplus of horsepower available to climb the aircraft is therefore reduced and so is the rate of climb
on the PA vs PR graph what will lowering flap do?
flap will reduce the gap between the two curves and will move the power required curve up and to the left.
what are the forces in descending flight?
(W) - weight acts from the centre of gravity towards the centre of earth
(TR) - Total reaction, equal and opposite to weight, and broken down into Lift and Drag
(L) - Lift acts from the centre of pressure 90 degrees to the relative airflow
(D) - drag acts in line with the relative airflow opposing motion
(W1) - weight one, weight acting from its CoG towards the Centre of earth
(FCW) - forward component of weight, because aircraft is pointing downhill
what are the factors affecting descending flight?
airspeed
wind
flap
weight
how does airspeed affect descent?
Any deviation from the best lift to drag ratio will result in a decreased gliding range because changing airspeed will result in an increase in drag.
power reduces the rate and angle of descent, therefore in a normal descent, you’ll use power to control these factors.
