Ch 3 - Aircraft Loads

Question 1

Two types of loads considered in this course?

Answer 1

Manoeuvres and gusts (symmetrical)

Question 2

Define the vertical equilibrium of an aircraft in a constant speed manoeuvre, highlighting load factor.

Answer 2

L + P = Mg + Maj = Mg(1+ (aj/g)) = nW where n is load factor.
L = Wing lift
P = Tail lift
Mg = Weight of plane
aj = Acceleration necessary for manoeuvre
(Maj) represents force to enable acceleration / manoeuvre

Question 3

What is the value of n in SLF?

Answer 3

1

Question 4

What is the value of n in parabolic, zero g flight?

Answer 4

0

Question 5

Define nmax (just before stall)

Answer 5

nmax = (0.5rhoV^2SClmax)/W

Question 6

Drawing reference to the equilibrium diagram of an aircraft and starting with the rotational equilibrium equation, derive an expression for the Clmax of an aircraft.

Answer 6

Pl = La +Mo
P = (L/l)*a + (1/l)*Mo
P + L = L(1 + (a/l)) + (1/l)*Mo
Clmax(aircraft) = Clmax(wing)*(1+(a/l))+(cbar/l)*Cmo
See 141 bresslof

Question 7

Define n (load factor)

Answer 7

n = (L + P)/W 
n = (1 + (aj/g))
nmax = (0.5*rho*V^2*S*Clmax)/W