Gliding and Climbing flight

Question 1

What are the forces experienced during gliding flight

Answer 1

Lift, Drag, Weight

Question 2

Equation for glide angle

Answer 2

Cd
tan γ = ——
Cl

Question 3

How should the distance travelled be maximised

Answer 3

fly at Cd/Cl min

Question 4

Simple equation for sink speed

Answer 4

Vs = V * sin γ

where γ is glide angle

Question 5

Equation for sink speed with respect to Cl and Cd

Answer 5

( 2 * mg ) Cd
SQRT( ———– ) * —————————
( ρ * S ) Cl^3/2

Question 6

What power condition would lead to the minimum sink speed

Answer 6

minimum power

i.e Cd/(Cl^3/2)

Question 7

What are the forces experienced during climbing flight

Answer 7

Lift, Drag, Weight, Thrust

Question 8

What is the assumption usually made about the rate of climb

Answer 8

assumed to be constant

i.e. dv/dt = 0

Question 9

How is thrust related to speed in a jet a/c

Answer 9

Thrust is independent of speed

Question 10

Equation for climb speed

Answer 10

Vc = Vsinθ = (TV -DV)/mg

Question 11

In the more complex equation for climb speed, what does the symbol τ (tau) represent

Answer 11

τ = T / mg

Question 12

How should the a/c be flown to achieve max climb angle

Answer 12

max climb angle corresponds to minimum drag

i.e. Cd/Cl is at minimum

Question 13

What is the absolute ceiling of an a/c

Answer 13

The maximum altitude an a/c can get to. Therefore the angle and rate of climb = 0
Therefore the is no freedom to manoeuvre other than to reduce altitude

Question 14

In practice, what is the surface ceiling of an a/c

Answer 14

The altitude at which the rate of climb has fallen to 100feet/minute
(0.5m/s)