Aircraft performance

Question 1

Equation for no-lift drag term

Answer 1

Dnl = 1/2 . p . V^2 . S . a

Question 2

Equation for lift-dependent drag term

Answer 2

b(mg)^2 / ( 0.5 . p . V^2 . S )

Question 3

Equation relating power and drag

Answer 3

P = D . v 
Power = Drag x velocity

Question 4

At what conditions do pilots normally prefer to fly at

Answer 4

Minimum drag

Question 5

What is Cd and Cl ‘s relationship with minimum power

Answer 5

Cd / (Cl^3/2)

Question 6

What is Cd and Cl ‘s relationship with minimum drag

Answer 6

Cd / Cl

Question 7

What is a and b ‘s relationship with minimum power

Answer 7

SQRT(3a/b)

Question 8

What is a and b ‘s relationship with minimum drag

Answer 8

SQRT(a/b)

Question 9

How does thrust vary for a jet engine as velocity increases

Answer 9

Does not vary much

Question 10

How does drag vary for a jet engine as velocity increases

Answer 10

Decrease then increases

y=x^2 shape

Question 11

At what point on a T,D vs. V graph is there maximum acceleration

Answer 11

Greatest difference between thrust and drag

Question 12

At what point on a T,D vs. V graph is there maximum velocity

Answer 12

When lines intercept - i.e. when T=D

Question 13

Definition of safe operating range

Answer 13

Max. distance between 2 airfields, allowing for headwind, diversion, stacking, take-off/landing

Question 14

Definition of gross still air range

Answer 14

Assume aircraft starts and finishes at the same cruising altitude

Question 15

Defintion of MZFW

Answer 15

Maximum zero fuel weight

Question 16

Definition of MTOW

Answer 16

Maximum take-off weight

Question 17

Range Equation

Answer 17

Rmax = V/Fj.g . (Cl/Cd)max . ln(M0/M1)