1. Consider thrust is given as 120 N of force then, find the value of thrust in terms of pound of force.
a) 26.97 pound of force
b) 125 pound
c) 12.56 lb
d) 120 KN
Explanation: Thrust in pound of force = Thrust in newton*0.225 = 120*0.225 = 26.97 lb of force
2. If weight of an aircraft is increased then, thrust loading will _______
a) increase
b) decrease
c) will not change
d) exact half always
Explanation: Thrust loading of the aircraft is defined as the ratio of the thrust of the aircraft to the weight of that aircraft. Hence, thrust loading is inversely proportional to the aircraft weight. Hence, if weight is increased then the corresponding value of thrust loading will decrease
3. A twin turbo prop is flying with power loading of 12. What will be the maximum velocity?
a) 48.225 mph
b) 48.225 m/s
c) 48.225 km/h
d) 225.48 m/h
Explanation: Given, Power loading P.L. = 12.
P.L. is given by,
W/hp = 1 / (a*Vmaxc), for twin turbo prop a=0.012, c=0.5.
Hence, maximum velocity Vmax is given by,
12 = 1 / (0.012*Vmax0.5)
0.012*Vmax0.5 = 1/12.
Vmax0.5 = 1 / (0.012*12) = 6.944
Takin log at both sides,
0.5*ln (Vmax) = ln (6.944) = 1.937
Now, taking anti-log,
Vmax = e(1.937/0.5) = e3.875 = 48.225mph.
4. An A/C is cruising with thrust to weight of 0.9. If A/C is powered by prop engine then, find maximum lift to drag?
a) 1.11
b) 2.11
c) 3.12
d) 4.221
Explanation: Given, thrust loading at cruise T.L. = 0.9, prop aircraft.
For prop aircraft maximum L/D = Cruise L/D
Hence, T.L. = D/L.
Hence, cruise L/D = 1/(T/W) = 1/0.9 = 1.11.
5. An A/C is flying with thrust loading at take-off is 0.9. If thrust at take-off and cruse is equal then, determine the thrust loading during cruise.
a) 0.941
b) 0.951
c) 0.961
d) 0.98
Explanation:Given thrust at take-off = thrust at cruise = T
Cruise thrust loading is given by,
(T/W)cruise = (T/W)take-off * (Wtake-off / Wcruise).
For cruise Wcruise = 0.956 * Wtake-off
Hence,
(T/W)cruise = (T/W)take-off * (Wtake-off / 0.956*Wtake-off) = 0.9/0.956 = 0.941.
6. Wing loading is ratio of ___________
a) weight of the aircraft and the reference area of wing
b) reference area of wing and power of engine
c) lift to drag
d) aerodynamic force thrust to drag
Explanation: Wing loading is defined as the ratio of the weight of an aircraft to the reference area of wing. Similar to thrust loading, wing loading has major effects on the aircraft performance. Lift to drag ratio is defined as aerodynamic efficiency.
7. Wing loading will affect _____________
a) only stall speed
b) only ground roll
c) stall speed, climbing, ground roll etc
d) only climb
Explanation: Ratio of the weight of an aircraft to the reference area of wing is termed as wing loading. Wing loading will show the relation between surface area and the weight of an aircraft as a whole. Wing loading will have impact on stall speed, climbing, ground roll, take-off etc.
8. Design lift coefficient is determined by wing loading.
a) True
b) False
Explanation: Wing loading will affect the drag of aircraft. Wing loading directly affects the wetted area and span of the wing. Hence, based on adequate wing loading we can determine lift co-efficient as well.
9. Low wing loading will provide ___________
a) more space for fuel storage in wing
b) more space of fuel storage in cabin
c) less fuel storage
d) less lift
Explanation: Wing loading will affect the size of the wing, weight of aircraft etc. Wing loading is given by, Weight off aircraft divided by reference area. If wing loading is low then, the reference area is more. This shows that large wings are used which can store more fuel.
10. As a designer I want to reduce the empty weight of my aircraft. Therefore I will ______
a) increase wing loading
b) decrease wing loading
c) wing loading has no effect
d) will reduce by exactly half
Explanation: Wing loading is directly related to the weight of the aircraft. High wing loading refers to the small wings and vice-versa. Hence, to decrease the empty weight, we can increase the wing loading by reducing reference area.