Climbing + Descending

Question 1

Forces acting in steady climb

Answer 1

In a steady climb at a constant speed the forces must be in equilibrium so:
- Total thrust must balance the drag and RCW
- Lift must balance W1

Question 2

Weight components in a climb

Answer 2

Weight is split into 2 components:
- W1 (which acts at a right angle to the flight path)
- RCW (rearward component of weight which acts opposite and parallel to the flight path)

Note: as the climb becomes steeper the RCW increases and the W1 decreases

Question 3

Deriving the EP curve

Answer 3

The rate of climb at any given speed is determined by the excess PA over PR, when comparing a PA and PR curve the shaded area between the 2 curves is the excess power, this excess power can then be plotted against TAS to give the EP curve (or excess power curve)

Question 4

Where does the speed for maximum ROC occur on the EP curve

Answer 4

Peak of the EP curve

Question 5

Where does the speed for maximum angle of climb occur on the EP curve

Answer 5

Where a line drawn from the origin of the graph is at a tangential to the curve

Question 6

Vx

Answer 6

max angle of climb speed

Question 7

Vy

Answer 7

max rate of climb speed

Question 8

Normal climb speed vs Vx and Vy

Answer 8

Normal climb speed is usually done at max power and so normal climb speed will most likely be higher than Vx and Vy

Question 9

What factors effect climb performance

Answer 9

• Power applied
• Airspeed
• Flap / undercarriage extension
• Manoeuvring
• Altitude
• Temperature
• Wind
• Weight

Question 10

Climb performance effect of power applied

Answer 10

Decreased power = decreased climb performance

Since the amount of excess power over power required is reduced

Question 11

Climb performance effect of airspeed

Answer 11

Flying faster or slower than the recommend airspeed can reduce climb performance

Question 12

Climb performance effect of Flap /undercarriage extension

Answer 12

Extended flaps / undercarriage will decrease climb performance because the L/D ratio is reduced (as drag is increased)

Question 13

Climb performance effect of weight

Answer 13

Increased weight = decreased climb performance due to the PR to maintain any given speed in level flight increases so there is a smaller excess available for climbing

Question 14

Climb performance effect of altitude

Answer 14

Increased altitude = decreased density = decreased airframe and engine performance so climb performance is reduced

Question 15

Climb performance effect of wind

Answer 15

Headwind and tailwind components effect the climb angle but not the ROC (so the altitude gain is the same but headwind reduces the distance traveled over the ground in a given time and tailwind increases it)

Question 16

Climb performance effect of manoeuvring

Answer 16

Any manoeuvring in the climb e.g. turning, will absorb some of the excess power available and climb performance is reduced

Question 17

Climb performance effect of temperature

Answer 17

At any altitude where where the air temp is higher than the standard figure the climb performance is reduced due to decreased density

Question 18

Absolute ceiling

Answer 18

As altitude increases the PR and PA curves move closer together , if the climb is continued the PR / PA curves will coincide and all PA will be needed to keep the a/c in level flight. The point where the curves coincide is called the absolute ceiling

Question 19

Service ceiling

Answer 19

Is reached when the ROC has been reduced to 100 ft / min and occurs at a lower altitude then the absolute ceiling

Question 20

Ways to descend

Answer 20

• Glide (throttle is closed so theres no thrust produced)
• Power on descent

Question 21

Forces acting on a a/c in a steady glide

Answer 21

There is no thrust
- Drag is balanced by the component of weight parallel to the flight path
- Lift is balanced by the component of weight that is perpendicular to the flight path

Question 22

Forces acting on an a/c in a steady power on descent

Answer 22

• Drag is balanced by the thrust and the component of weight parallel to the flight path
• Lift is balanced by the component of weight that is perpendicular to the flight path

Question 23

What determines the glide angle at any given speed

Answer 23

The L/D ratio. If the L/D ratio is high the glide angle will be shallow and vice versa . The glide angle is in dierct proprtion to the L/D ratio.

Question 24

How is the greatest range (and shallowest angle) in the glide achieved

Answer 24

When the a/c is flown at the AoA for the best L/D ratio (speed at the peak of the L/D curve), If glide speed is lower or higher than recommend the L/D ratio will be not as good and the glide angle will be steeper

Question 25

Effect of weight of glide performance

Answer 25

Weight has no effect on glide angle

Decreasing weight means the AoA for the best L/D ratio will occur at a lower airspeed, and so the ROD will be slightly lower and the time taken to reach the ground will be longer

Question 26

Effect of wind of glide performance

Answer 26

Headwind reduces the glide distance over the ground but doesn’t effect the glide distance through the air mss. Net flight path is steeper in headwind and shallowing in tailwind