# Aircraft Performance Questions and Answers – Effect of Wind on Climb Performance and Descent Performance

This set of Aircraft Performance Questions and Answers for Entrance exams focuses on “Effect of Wind on Climb Performance and Descent Performance”.

1. Wind is the relative velocity between the air mass and the ground.
a) True
b) False

Explanation: Wind is the relative velocity between the air mass and the ground. Usually wind is assumed to have only a horizontal component but there exists vertical component which may affect the aircraft at considerable height.

2. The aircraft is taken to the level ground operating for ________
a) considering vertical component of the wind
b) considering horizontal component of the wind
c) considering both horizontal and vertical component of the wind
d) neglecting the effect of wind

Explanation: The aircraft is taken to the level ground operating for considering horizontal component of the wind. Wind is the relative velocity between the air mass and the ground. Usually wind is assumed to have only a horizontal component but there exists vertical component which may affect the aircraft at considerable height.

3. The relative velocity of the wind produces boundary layer close to the ground which ___________
a) decreases the wind speed with decrease in height
b) increases the wind speed with decrease in height
c) makes the wind speed unaffected
d) constantly increases

Explanation: The relative velocity of the wind produces boundary layer close to the ground which decreases the wind speed with decrease in height. This will further produce effects on the aircraft.

4. The flight path is calculated relative to ________
a) air mass
b) still air condition
c) air mass and still air condition
d) airspeed

Explanation: The flight path is calculated relative to air mass. This resulted in the development of the theory by experimenting in the still air condition. In actual performance of the aircraft the relative velocity is not effected by the reference axis as they are velocity axes.

5. It is assumed zero velocity datum at the aerodynamic center of the aircraft.
a) True
b) False

Explanation: It is assumed zero velocity datum at the center of gravity (CG) of the aircraft. Centre of gravity (CG) of an aircraft is the point at which the whole weight of the aircraft is being balanced. This CG does not change with respect to speed of the aircraft.

6. The performance relative to ground is effected by the wind.
a) True
b) False

Explanation: The performance relative to ground is effected by the wind. The relative velocity of the wind produces boundary layer close to the ground which decreases the wind speed with decrease in height. This will further produce effects on the aircraft.

7. What is meant by perceived performance?
a) Visualization of the aircraft with respect to wind
b) Visualization of the aircraft with respect to aircraft relative to ground
c) Visualization of the aircraft with respect to wind with respect to ground
d) Visualization of the aircraft with respect to any one frame such as aircraft or ground

Explanation: Visualization of the aircraft with respect to any one frame such as aircraft or ground is known as the perceived performance. This effects the ability of the aircraft to clear ground-based obstructions.

8. The rate of climb or descent relative to air mass is unaffected by the tailwind.
a) True
b) False

Explanation: The rate of climb or descent relative to air mass is unaffected by the wind but the horizontal component of true airspeed is effected by the tailwind. The effect is increased by tailwind and decreased by the headwind.

9. The horizontal component of the true airspeed is _______________
a) increased by tailwind
b) decreased by tailwind
d) unaffected by the airspeed

Explanation: The rate of climb or descent relative to air mass is unaffected by the wind but the horizontal component of true airspeed is effected by the tailwind. The effect is increased by tailwind and decreased by the headwind.

10. What is wind shear?
a) The extreme case of airspeed effect on the aircraft
b) The extreme case of wind effect on the aircraft
c) The extreme case of temperature effect on the wind
d) The extreme case of altitude effect on the wind

Explanation: The extreme case of wind effect on the aircraft is known as the wind shear. In this case the rate of change of the wind speed is very high. This effect is caused by the meteorological conditions.

Sanfoundry Global Education & Learning Series – Aircraft Performance.

To practice all areas of Aircraft Performance for Entrance exams, here is complete set of 1000+ Multiple Choice Questions and Answers.