Design and Analysis of Aircraft with Adjustable Components:
Mathematical MCQ Problems
1. What is the aspect ratio of a wing with a span of 30 m and an area of 150 m²?
a) 4
b) 5
c) 6
d) 7
Answer: c) 6
2. An aircraft weighing 50,000 N is flying at sea level with a velocity of 100 m/s and a wing area of
120 m². What is its lift coefficient?
a) 0.28
b) 0.34
c) 0.40
d) 0.46
Answer: b) 0.34
3. If the wingspan of an aircraft is increased by 20%, by what percentage does the aspect ratio
increase, assuming the wing area remains constant?
a) 20%
b) 32%
c) 44%
d) 56%
Answer: c) 44%
4. An aircraft's weight increases from 10,000 kg to 12,000 kg, while its wing area remains constant at
50 m². What is the new wing loading?
a) 1,962 N/m²
b) 2,158 N/m²
c) 2,354 N/m²
d) 2,550 N/m²
Answer: c) 2,354 N/m²
5. The aspect ratio of a wing increases from 8 to 10. Assuming the lift coefficient remains constant,
what is the percentage change in induced drag coefficient?
a) 10% decrease
b) 15% decrease
c) 20% decrease
d) 25% decrease
Answer: c) 20% decrease
6. If the sweep angle of a wing is increased from 25° to 35°, what is the percentage change in the
effective wing span?
a) 5.7% decrease
b) 8.3% decrease
c) 10.9% decrease
d) 13.5% decrease
Answer: b) 8.3% decrease
7. An aircraft's maximum lift coefficient increases from 1.5 to 1.8 due to the deployment of high-lift
devices. What is the percentage change in stall speed?
a) 5.3% decrease
b) 8.7% decrease
c) 11.1% decrease
d) 13.5% decrease
Answer: b) 8.7% decrease
8. If the wing area is increased by 15% through the use of extensible wingtips, what is the percentage
increase in maximum lift coefficient?
a) 10% increase
b) 15% increase
c) 20% increase
d) 25% increase
Answer: b) 15% increase
9. An aircraft has a tail volume coefficient of 0.6 and a wing area of 100 m². If the tail arm is 15 m,
what is the required horizontal tail area?
a) 3 m²
b) 4 m²
c) 5 m²
d) 6 m²
Answer: b) 4 m²
10. Winglets are added to an aircraft, reducing the effective aspect ratio by 20%. What is the
percentage change in the induced drag factor?
a) 10.5% decrease
b) 13.6% decrease
c) 16.7% decrease
d) 19.8% decrease
Answer: c) 16.7% decrease
11. The parasite drag coefficient decreases by 10% and the induced drag coefficient increases by 5%.
What can be said about the change in lift-to-drag ratio?
a) It always increases
b) It always decreases
c) It remains the same
d) It depends on the original lift and drag coefficients
Answer: d) It depends on the original lift and drag coefficients
12. If the dihedral angle of a wing is increased from 3° to 5°, what is the percentage change in the
lateral stability derivative?
a) 33.3% increase
b) 50.0% increase
c) 66.7% increase
d) 83.3% increase
Answer: c) 66.7% increase
13. An aircraft's weight is reduced by 8% and the wing area is increased by 5%. What is the
percentage change in wing loading?
a) 8.7% decrease
b) 10.5% decrease
c) 12.4% decrease
d) 14.3% decrease
Answer: c) 12.4% decrease
14. The wing sweep is increased from 0° to 30°. What is the approximate percentage change in the
critical Mach number?
a) 10.5% increase
b) 15.5% increase
c) 20.5% increase
d) 25.5% increase
Answer: b) 15.5% increase
15. If the aspect ratio of a wing is doubled, what is the percentage change in the lift curve slope?
a) 25.0% increase
b) 33.3% increase
c) 41.7% increase
d) 50.0% increase
Answer: b) 33.3% increase
16. An aircraft's weight increases by 20% and its velocity decreases by 10%. What is the percentage
change in the lift coefficient required for level flight?
a) 32.5% increase
b) 40.3% increase
c) 48.1% increase
d) 55.9% increase
Answer: c) 48.1% increase
17. The chord of a wing is increased by 10% while maintaining the same wingspan. What is the
percentage change in the wing's wetted area?
a) 5% increase
b) 10% increase
c) 15% increase
d) 20% increase
Answer: b) 10% increase
18. The tail incidence angle is changed from 2° to -1°. What is the change in the aircraft's pitch trim?
a) 1° nose-down
b) 2° nose-down
c) 3° nose-down
d) 4° nose-down
Answer: c) 3° nose-down
19. The wingspan is increased by 25% while maintaining the same wing area. What is the percentage
change in the induced drag coefficient?
a) 24% decrease
b) 30% decrease
c) 36% decrease
d) 42% decrease
Answer: c) 36% decrease
20. If the aileron area is increased by 15%, what is the approximate percentage change in the
aircraft's roll rate?
a) 10% increase
b) 15% increase
c) 20% increase
d) 25% increase
Answer: b) 15% increase
21. The wing's quarter-chord sweep angle is increased from 20° to 30°. What is the approximate
percentage change in the wing's critical Mach number?
a) 5.7% increase
b) 7.7% increase
c) 9.7% increase
d) 11.7% increase
Answer: b) 7.7% increase
22. The center of gravity is moved forward by 5% of the mean aerodynamic chord. What is the
change in the static margin?
a) 3% increase
b) 4% increase
c) 5% increase
d) 6% increase
Answer: c) 5% increase
23. The flap deflection angle is increased from 20° to 30°. Which statement is true about the change
in maximum lift coefficient?
a) It always increases by 10%
b) It always increases by 20%
c) It always decreases
d) It depends on the airfoil and flap type
Answer: d) It depends on the airfoil and flap type
24. If the winglet height is increased by 20%, what is the approximate percentage reduction in
induced drag?
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Answer: b) 4% decrease (assuming 20% effectiveness)
25. The wing aspect ratio is increased from 7 to 9. What is the approximate percentage change in the
Oswald efficiency factor?
a) 4.7% increase
b) 5.7% increase
c) 6.7% increase
d) 7.7% increase
Answer: c) 6.7% increase (assuming typical relationship)
26. The vertical tail area is increased by 12%. What is the percentage change in the aircraft's
directional stability?
a) 8% increase
b) 10% increase
c) 12% increase
d) 14% increase
Answer: c) 12% increase (assuming linear relationship)
27. An aircraft's weight is reduced by 10% and the wing area is decreased by 5%. Calculate the
percentage change in the stall speed using the equation: Vs ∝ √(W/S).
a) 1.3% decrease
b) 2.6% decrease
c) 3.9% decrease
d) 5.2% decrease
Solution:
Vs_new / Vs_old = √[(0.9W / 0.95S) / (W/S)] = √(0.9/0.95) = 0.974
Percentage change = (0.974 - 1) × 100% = -2.6%
Answer: b) 2.6% decrease
28. Both the lift and drag coefficients increase by 5%. Calculate the new lift-to-drag ratio.
a) 5% increase
b) No change
c) 5% decrease
d) Cannot be determined without original values
Solution:
New L/D = (1.05CL) / (1.05CD) = CL / CD = Original L/D
Answer: b) No change
29. The wingspan is increased by 15% while maintaining the same lift distribution. What is the
percentage change in the wing root bending moment?
a) 15% increase
b) 23.7% increase
c) 32.3% increase
d) 41% increase
Solution:
Bending moment ∝ span^2
New moment / Old moment = (1.15 × span)^2 / span^2 = 1.3225
Percentage change = (1.3225 - 1) × 100% = 32.25%
Answer: c) 32.3% increase
30. The horizontal tail volume coefficient is increased from 0.7 to 0.8. What is the percentage change
in the aircraft's pitch damping?
a) 10% increase
b) 12.5% increase
c) 14.3% increase
d) 16.7% increase
Solution:
Percentage change = (0.8 - 0.7) / 0.7 × 100% = 14.3%
Answer: c) 14.3% increase
31. The wing span is increased by 10% and the wing area is decreased by 5%. Calculate the
percentage change in aspect ratio using the equation: AR = b^2 / S.
a) 20.5% increase
b) 23.7% increase
c) 27.3% increase
d) 31.6% increase
Solution:
New AR / Old AR = (1.1b)^2 / (0.95S) / (b^2/S) = 1.21 / 0.95 = 1.273
Percentage change = (1.273 - 1) × 100% = 27.3%
Answer: c) 27.3% increase
32. The wingspan is increased by 8%. What is the percentage change in the aircraft's roll inertia,
given that roll inertia is proportional to the square of the wingspan?
a) 8% increase
b) 12.3% increase
c) 16.6% increase
d) 20.9% increase
Solution:
New inertia / Old inertia = (1.08 × span)^2 / span^2 = 1.1664
Percentage change = (1.1664 - 1) × 100% = 16.64%
Answer: c) 16.6% increase
33. The wing twist (washout) is increased from 2° to 3°. Estimate the change in the induced drag
coefficient, assuming an elliptical lift distribution and that each degree of washout reduces induced
drag by 2%.
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Solution:
Change in washout = 3° - 2° = 1°
Induced drag reduction = 1° × 2% = 2%
Answer: a) 2% decrease
34. The aircraft's velocity is increased by 20% at the same altitude. Calculate the percentage change
in dynamic pressure using the equation: q = 1/2 ρV^2.
a) 20% increase
b) 32% increase
c) 44% increase
d) 56% increase
Solution:
New q / Old q = (1.2V)^2 / V^2 = 1.44
Percentage change = (1.44 - 1) × 100% = 44%
Answer: c) 44% increase
35. The fuselage length is increased by 5%. What is the percentage change in the aircraft's pitch
moment of inertia, assuming it is proportional to the square of the fuselage length?
a) 5% increase
b) 7.7% increase
c) 10.3% increase
d) 12.9% increase
Solution:
New inertia / Old inertia = (1.05 × length)^2 / length^2 = 1.1025
Percentage change = (1.1025 - 1) × 100% = 10.25%
Answer: c) 10.3% increase
Winglets are added to an aircraft, reducing the effective aspect ratio by 20%. What is the percentage
change in the induced drag factor?
a) 10.5% decrease
b) 13.6% decrease
c) 16.7% decrease
d) 19.8% decrease
Answer: c) 16.7% decrease
11. The parasite drag coefficient decreases by 10% and the induced drag coefficient increases by 5%.
What can be said about the change in lift-to-drag ratio?
a) It always increases
b) It always decreases
c) It remains the same
d) It depends on the original lift and drag coefficients
Answer: d) It depends on the original lift and drag coefficients
12. If the dihedral angle of a wing is increased from 3° to 5°, what is the percentage change in the
lateral stability derivative?
a) 33.3% increase
b) 50.0% increase
c) 66.7% increase
d) 83.3% increase
Answer: c) 66.7% increase
13. An aircraft's weight is reduced by 8% and the wing area is increased by 5%. What is the
percentage change in wing loading?
a) 8.7% decrease
b) 10.5% decrease
c) 12.4% decrease
d) 14.3% decrease
Answer: c) 12.4% decrease
14. The wing sweep is increased from 0° to 30°. What is the approximate percentage change in the
critical Mach number?
a) 10.5% increase
b) 15.5% increase
c) 20.5% increase
d) 25.5% increase
Answer: b) 15.5% increase
15. If the aspect ratio of a wing is doubled, what is the percentage change in the lift curve slope?
a) 25.0% increase
b) 33.3% increase
c) 41.7% increase
d) 50.0% increase
Answer: b) 33.3% increase
16. An aircraft's weight increases by 20% and its velocity decreases by 10%. What is the percentage
change in the lift coefficient required for level flight?
a) 32.5% increase
b) 40.3% increase
c) 48.1% increase
d) 55.9% increase
Answer: c) 48.1% increase
17. The chord of a wing is increased by 10% while maintaining the same wingspan. What is the
percentage change in the wing's wetted area?
a) 5% increase
b) 10% increase
c) 15% increase
d) 20% increase
Answer: b) 10% increase
18. The tail incidence angle is changed from 2° to -1°. What is the change in the aircraft's pitch trim?
a) 1° nose-down
b) 2° nose-down
c) 3° nose-down
d) 4° nose-down
Answer: c) 3° nose-down
19. The wingspan is increased by 25% while maintaining the same wing area. What is the percentage
change in the induced drag coefficient?
a) 24% decrease
b) 30% decrease
c) 36% decrease
d) 42% decrease
Answer: c) 36% decrease
20. If the aileron area is increased by 15%, what is the approximate percentage change in the
aircraft's roll rate?
a) 10% increase
b) 15% increase
c) 20% increase
d) 25% increase
Answer: b) 15% increase
21. The wing's quarter-chord sweep angle is increased from 20° to 30°. What is the approximate
percentage change in the wing's critical Mach number?
a) 5.7% increase
b) 7.7% increase
c) 9.7% increase
d) 11.7% increase
Answer: b) 7.7% increase
22. The center of gravity is moved forward by 5% of the mean aerodynamic chord. What is the
change in the static margin?
a) 3% increase
b) 4% increase
c) 5% increase
d) 6% increase
Answer: c) 5% increase
23. The flap deflection angle is increased from 20° to 30°. Which statement is true about the change
in maximum lift coefficient?
a) It always increases by 10%
b) It always increases by 20%
c) It always decreases
d) It depends on the airfoil and flap type
Answer: d) It depends on the airfoil and flap type
24. If the winglet height is increased by 20%, what is the approximate percentage reduction in
induced drag?
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Answer: b) 4% decrease (assuming 20% effectiveness)
25. The wing aspect ratio is increased from 7 to 9. What is the approximate percentage change in the
Oswald efficiency factor?
a) 4.7% increase
b) 5.7% increase
c) 6.7% increase
d) 7.7% increase
Answer: c) 6.7% increase (assuming typical relationship)
26. The vertical tail area is increased by 12%. What is the percentage change in the aircraft's
directional stability?
a) 8% increase
b) 10% increase
c) 12% increase
d) 14% increase
Answer: c) 12% increase (assuming linear relationship)
27. An aircraft's weight is reduced by 10% and the wing area is decreased by 5%. Calculate the
percentage change in the stall speed using the equation: Vs ∝ √(W/S).
a) 1.3% decrease
b) 2.6% decrease
c) 3.9% decrease
d) 5.2% decrease
Solution:
Vs_new / Vs_old = √[(0.9W / 0.95S) / (W/S)] = √(0.9/0.95) = 0.974
Percentage change = (0.974 - 1) × 100% = -2.6%
Answer: b) 2.6% decrease
28. Both the lift and drag coefficients increase by 5%. Calculate the new lift-to-drag ratio.
a) 5% increase
b) No change
c) 5% decrease
d) Cannot be determined without original values
Solution:
New L/D = (1.05CL) / (1.05CD) = CL / CD = Original L/D
Answer: b) No change
29. The wingspan is increased by 15% while maintaining the same lift distribution. What is the
percentage change in the wing root bending moment?
a) 15% increase
b) 23.7% increase
c) 32.3% increase
d) 41% increase
Solution:
Bending moment ∝ span^2
New moment / Old moment = (1.15 × span)^2 / span^2 = 1.3225
Percentage change = (1.3225 - 1) × 100% = 32.25%
Answer: c) 32.3% increase
30. The horizontal tail volume coefficient is increased from 0.7 to 0.8. What is the percentage change
in the aircraft's pitch damping?
a) 10% increase
b) 12.5% increase
c) 14.3% increase
d) 16.7% increase
Solution:
Percentage change = (0.8 - 0.7) / 0.7 × 100% = 14.3%
Answer: c) 14.3% increase
31. The wing span is increased by 10% and the wing area is decreased by 5%. Calculate the
percentage change in aspect ratio using the equation: AR = b^2 / S.
a) 20.5% increase
b) 23.7% increase
c) 27.3% increase
d) 31.6% increase
Solution:
New AR / Old AR = (1.1b)^2 / (0.95S) / (b^2/S) = 1.21 / 0.95 = 1.273
Percentage change = (1.273 - 1) × 100% = 27.3%
Answer: c) 27.3% increase
32. The wingspan is increased by 8%. What is the percentage change in the aircraft's roll inertia,
given that roll inertia is proportional to the square of the wingspan?
a) 8% increase
b) 12.3% increase
c) 16.6% increase
d) 20.9% increase
Solution:
New inertia / Old inertia = (1.08 × span)^2 / span^2 = 1.1664
Percentage change = (1.1664 - 1) × 100% = 16.64%
Answer: c) 16.6% increase
33. The wing twist (washout) is increased from 2° to 3°. Estimate the change in the induced drag
coefficient, assuming an elliptical lift distribution and that each degree of washout reduces induced
drag by 2%.
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Solution:
Change in washout = 3° - 2° = 1°
Induced drag reduction = 1° × 2% = 2%
Answer: a) 2% decrease
34. The aircraft's velocity is increased by 20% at the same altitude. Calculate the percentage change
in dynamic pressure using the equation: q = 1/2 ρV^2.
a) 20% increase
b) 32% increase
c) 44% increase
d) 56% increase
Solution:
New q / Old q = (1.2V)^2 / V^2 = 1.44
Percentage change = (1.44 - 1) × 100% = 44%
Answer: c) 44% increase
35. The fuselage length is increased by 5%. What is the percentage change in the aircraft's pitch
moment of inertia, assuming it is proportional to the square of the fuselage length?
a) 5% increase
b) 7.7% increase
c) 10.3% increase
d) 12.9% increase
Solution:
New inertia / Old inertia = (1.05 × length)^2 / length^2 = 1.1025
Percentage change = (1.1025 - 1) × 100% = 10.25%
Answer: c) 10.3% increase
Winglets are added to an aircraft, reducing the effective aspect ratio by 20%. What is the percentage
change in the induced drag factor?
a) 10.5% decrease
b) 13.6% decrease
c) 16.7% decrease
d) 19.8% decrease
Answer: c) 16.7% decrease
11. The parasite drag coefficient decreases by 10% and the induced drag coefficient increases by 5%.
What can be said about the change in lift-to-drag ratio?
a) It always increases
b) It always decreases
c) It remains the same
d) It depends on the original lift and drag coefficients
Answer: d) It depends on the original lift and drag coefficients
12. If the dihedral angle of a wing is increased from 3° to 5°, what is the percentage change in the
lateral stability derivative?
a) 33.3% increase
b) 50.0% increase
c) 66.7% increase
d) 83.3% increase
Answer: c) 66.7% increase
13. An aircraft's weight is reduced by 8% and the wing area is increased by 5%. What is the
percentage change in wing loading?
a) 8.7% decrease
b) 10.5% decrease
c) 12.4% decrease
d) 14.3% decrease
Answer: c) 12.4% decrease
14. The wing sweep is increased from 0° to 30°. What is the approximate percentage change in the
critical Mach number?
a) 10.5% increase
b) 15.5% increase
c) 20.5% increase
d) 25.5% increase
Answer: b) 15.5% increase
15. If the aspect ratio of a wing is doubled, what is the percentage change in the lift curve slope?
a) 25.0% increase
b) 33.3% increase
c) 41.7% increase
d) 50.0% increase
Answer: b) 33.3% increase
16. An aircraft's weight increases by 20% and its velocity decreases by 10%. What is the percentage
change in the lift coefficient required for level flight?
a) 32.5% increase
b) 40.3% increase
c) 48.1% increase
d) 55.9% increase
Answer: c) 48.1% increase
17. The chord of a wing is increased by 10% while maintaining the same wingspan. What is the
percentage change in the wing's wetted area?
a) 5% increase
b) 10% increase
c) 15% increase
d) 20% increase
Answer: b) 10% increase
18. The tail incidence angle is changed from 2° to -1°. What is the change in the aircraft's pitch trim?
a) 1° nose-down
b) 2° nose-down
c) 3° nose-down
d) 4° nose-down
Answer: c) 3° nose-down
19. The wingspan is increased by 25% while maintaining the same wing area. What is the percentage
change in the induced drag coefficient?
a) 24% decrease
b) 30% decrease
c) 36% decrease
d) 42% decrease
Answer: c) 36% decrease
20. If the aileron area is increased by 15%, what is the approximate percentage change in the
aircraft's roll rate?
a) 10% increase
b) 15% increase
c) 20% increase
d) 25% increase
Answer: b) 15% increase
21. The wing's quarter-chord sweep angle is increased from 20° to 30°. What is the approximate
percentage change in the wing's critical Mach number?
a) 5.7% increase
b) 7.7% increase
c) 9.7% increase
d) 11.7% increase
Answer: b) 7.7% increase
22. The center of gravity is moved forward by 5% of the mean aerodynamic chord. What is the
change in the static margin?
a) 3% increase
b) 4% increase
c) 5% increase
d) 6% increase
Answer: c) 5% increase
23. The flap deflection angle is increased from 20° to 30°. Which statement is true about the change
in maximum lift coefficient?
a) It always increases by 10%
b) It always increases by 20%
c) It always decreases
d) It depends on the airfoil and flap type
Answer: d) It depends on the airfoil and flap type
24. If the winglet height is increased by 20%, what is the approximate percentage reduction in
induced drag?
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Answer: b) 4% decrease (assuming 20% effectiveness)
25. The wing aspect ratio is increased from 7 to 9. What is the approximate percentage change in the
Oswald efficiency factor?
a) 4.7% increase
b) 5.7% increase
c) 6.7% increase
d) 7.7% increase
Answer: c) 6.7% increase (assuming typical relationship)
26. The vertical tail area is increased by 12%. What is the percentage change in the aircraft's
directional stability?
a) 8% increase
b) 10% increase
c) 12% increase
d) 14% increase
Answer: c) 12% increase (assuming linear relationship)
27. An aircraft's weight is reduced by 10% and the wing area is decreased by 5%. Calculate the
percentage change in the stall speed using the equation: Vs ∝ √(W/S).
a) 1.3% decrease
b) 2.6% decrease
c) 3.9% decrease
d) 5.2% decrease
Solution:
Vs_new / Vs_old = √[(0.9W / 0.95S) / (W/S)] = √(0.9/0.95) = 0.974
Percentage change = (0.974 - 1) × 100% = -2.6%
Answer: b) 2.6% decrease
28. Both the lift and drag coefficients increase by 5%. Calculate the new lift-to-drag ratio.
a) 5% increase
b) No change
c) 5% decrease
d) Cannot be determined without original values
Solution:
New L/D = (1.05CL) / (1.05CD) = CL / CD = Original L/D
Answer: b) No change
29. The wingspan is increased by 15% while maintaining the same lift distribution. What is the
percentage change in the wing root bending moment?
a) 15% increase
b) 23.7% increase
c) 32.3% increase
d) 41% increase
Solution:
Bending moment ∝ span^2
New moment / Old moment = (1.15 × span)^2 / span^2 = 1.3225
Percentage change = (1.3225 - 1) × 100% = 32.25%
Answer: c) 32.3% increase
30. The horizontal tail volume coefficient is increased from 0.7 to 0.8. What is the percentage change
in the aircraft's pitch damping?
a) 10% increase
b) 12.5% increase
c) 14.3% increase
d) 16.7% increase
Solution:
Percentage change = (0.8 - 0.7) / 0.7 × 100% = 14.3%
Answer: c) 14.3% increase
31. The wing span is increased by 10% and the wing area is decreased by 5%. Calculate the
percentage change in aspect ratio using the equation: AR = b^2 / S.
a) 20.5% increase
b) 23.7% increase
c) 27.3% increase
d) 31.6% increase
Solution:
New AR / Old AR = (1.1b)^2 / (0.95S) / (b^2/S) = 1.21 / 0.95 = 1.273
Percentage change = (1.273 - 1) × 100% = 27.3%
Answer: c) 27.3% increase
32. The wingspan is increased by 8%. What is the percentage change in the aircraft's roll inertia,
given that roll inertia is proportional to the square of the wingspan?
a) 8% increase
b) 12.3% increase
c) 16.6% increase
d) 20.9% increase
Solution:
New inertia / Old inertia = (1.08 × span)^2 / span^2 = 1.1664
Percentage change = (1.1664 - 1) × 100% = 16.64%
Answer: c) 16.6% increase
33. The wing twist (washout) is increased from 2° to 3°. Estimate the change in the induced drag
coefficient, assuming an elliptical lift distribution and that each degree of washout reduces induced
drag by 2%.
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Solution:
Change in washout = 3° - 2° = 1°
Induced drag reduction = 1° × 2% = 2%
Answer: a) 2% decrease
34. The aircraft's velocity is increased by 20% at the same altitude. Calculate the percentage change
in dynamic pressure using the equation: q = 1/2 ρV^2.
a) 20% increase
b) 32% increase
c) 44% increase
d) 56% increase
Solution:
New q / Old q = (1.2V)^2 / V^2 = 1.44
Percentage change = (1.44 - 1) × 100% = 44%
Answer: c) 44% increase
35. The fuselage length is increased by 5%. What is the percentage change in the aircraft's pitch
moment of inertia, assuming it is proportional to the square of the fuselage length?
a) 5% increase
b) 7.7% increase
c) 10.3% increase
d) 12.9% increase
Solution:
New inertia / Old inertia = (1.05 × length)^2 / length^2 = 1.1025
Percentage change = (1.1025 - 1) × 100% = 10.25%
Answer: c) 10.3% increase
Winglets are added to an aircraft, reducing the effective aspect ratio by 20%. What is the percentage
change in the induced drag factor?
a) 10.5% decrease
b) 13.6% decrease
c) 16.7% decrease
d) 19.8% decrease
Answer: c) 16.7% decrease
11. The parasite drag coefficient decreases by 10% and the induced drag coefficient increases by 5%.
What can be said about the change in lift-to-drag ratio?
a) It always increases
b) It always decreases
c) It remains the same
d) It depends on the original lift and drag coefficients
Answer: d) It depends on the original lift and drag coefficients
12. If the dihedral angle of a wing is increased from 3° to 5°, what is the percentage change in the
lateral stability derivative?
a) 33.3% increase
b) 50.0% increase
c) 66.7% increase
d) 83.3% increase
Answer: c) 66.7% increase
13. An aircraft's weight is reduced by 8% and the wing area is increased by 5%. What is the
percentage change in wing loading?
a) 8.7% decrease
b) 10.5% decrease
c) 12.4% decrease
d) 14.3% decrease
Answer: c) 12.4% decrease
14. The wing sweep is increased from 0° to 30°. What is the approximate percentage change in the
critical Mach number?
a) 10.5% increase
b) 15.5% increase
c) 20.5% increase
d) 25.5% increase
Answer: b) 15.5% increase
15. If the aspect ratio of a wing is doubled, what is the percentage change in the lift curve slope?
a) 25.0% increase
b) 33.3% increase
c) 41.7% increase
d) 50.0% increase
Answer: b) 33.3% increase
16. An aircraft's weight increases by 20% and its velocity decreases by 10%. What is the percentage
change in the lift coefficient required for level flight?
a) 32.5% increase
b) 40.3% increase
c) 48.1% increase
d) 55.9% increase
Answer: c) 48.1% increase
17. The chord of a wing is increased by 10% while maintaining the same wingspan. What is the
percentage change in the wing's wetted area?
a) 5% increase
b) 10% increase
c) 15% increase
d) 20% increase
Answer: b) 10% increase
18. The tail incidence angle is changed from 2° to -1°. What is the change in the aircraft's pitch trim?
a) 1° nose-down
b) 2° nose-down
c) 3° nose-down
d) 4° nose-down
Answer: c) 3° nose-down
19. The wingspan is increased by 25% while maintaining the same wing area. What is the percentage
change in the induced drag coefficient?
a) 24% decrease
b) 30% decrease
c) 36% decrease
d) 42% decrease
Answer: c) 36% decrease
20. If the aileron area is increased by 15%, what is the approximate percentage change in the
aircraft's roll rate?
a) 10% increase
b) 15% increase
c) 20% increase
d) 25% increase
Answer: b) 15% increase
21. The wing's quarter-chord sweep angle is increased from 20° to 30°. What is the approximate
percentage change in the wing's critical Mach number?
a) 5.7% increase
b) 7.7% increase
c) 9.7% increase
d) 11.7% increase
Answer: b) 7.7% increase
22. The center of gravity is moved forward by 5% of the mean aerodynamic chord. What is the
change in the static margin?
a) 3% increase
b) 4% increase
c) 5% increase
d) 6% increase
Answer: c) 5% increase
23. The flap deflection angle is increased from 20° to 30°. Which statement is true about the change
in maximum lift coefficient?
a) It always increases by 10%
b) It always increases by 20%
c) It always decreases
d) It depends on the airfoil and flap type
Answer: d) It depends on the airfoil and flap type
24. If the winglet height is increased by 20%, what is the approximate percentage reduction in
induced drag?
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Answer: b) 4% decrease (assuming 20% effectiveness)
25. The wing aspect ratio is increased from 7 to 9. What is the approximate percentage change in the
Oswald efficiency factor?
a) 4.7% increase
b) 5.7% increase
c) 6.7% increase
d) 7.7% increase
Answer: c) 6.7% increase (assuming typical relationship)
26. The vertical tail area is increased by 12%. What is the percentage change in the aircraft's
directional stability?
a) 8% increase
b) 10% increase
c) 12% increase
d) 14% increase
Answer: c) 12% increase (assuming linear relationship)
27. An aircraft's weight is reduced by 10% and the wing area is decreased by 5%. Calculate the
percentage change in the stall speed using the equation: Vs ∝ √(W/S).
a) 1.3% decrease
b) 2.6% decrease
c) 3.9% decrease
d) 5.2% decrease
Solution:
Vs_new / Vs_old = √[(0.9W / 0.95S) / (W/S)] = √(0.9/0.95) = 0.974
Percentage change = (0.974 - 1) × 100% = -2.6%
Answer: b) 2.6% decrease
28. Both the lift and drag coefficients increase by 5%. Calculate the new lift-to-drag ratio.
a) 5% increase
b) No change
c) 5% decrease
d) Cannot be determined without original values
Solution:
New L/D = (1.05CL) / (1.05CD) = CL / CD = Original L/D
Answer: b) No change
29. The wingspan is increased by 15% while maintaining the same lift distribution. What is the
percentage change in the wing root bending moment?
a) 15% increase
b) 23.7% increase
c) 32.3% increase
d) 41% increase
Solution:
Bending moment ∝ span^2
New moment / Old moment = (1.15 × span)^2 / span^2 = 1.3225
Percentage change = (1.3225 - 1) × 100% = 32.25%
Answer: c) 32.3% increase
30. The horizontal tail volume coefficient is increased from 0.7 to 0.8. What is the percentage change
in the aircraft's pitch damping?
a) 10% increase
b) 12.5% increase
c) 14.3% increase
d) 16.7% increase
Solution:
Percentage change = (0.8 - 0.7) / 0.7 × 100% = 14.3%
Answer: c) 14.3% increase
31. The wing span is increased by 10% and the wing area is decreased by 5%. Calculate the
percentage change in aspect ratio using the equation: AR = b^2 / S.
a) 20.5% increase
b) 23.7% increase
c) 27.3% increase
d) 31.6% increase
Solution:
New AR / Old AR = (1.1b)^2 / (0.95S) / (b^2/S) = 1.21 / 0.95 = 1.273
Percentage change = (1.273 - 1) × 100% = 27.3%
Answer: c) 27.3% increase
32. The wingspan is increased by 8%. What is the percentage change in the aircraft's roll inertia,
given that roll inertia is proportional to the square of the wingspan?
a) 8% increase
b) 12.3% increase
c) 16.6% increase
d) 20.9% increase
Solution:
New inertia / Old inertia = (1.08 × span)^2 / span^2 = 1.1664
Percentage change = (1.1664 - 1) × 100% = 16.64%
Answer: c) 16.6% increase
33. The wing twist (washout) is increased from 2° to 3°. Estimate the change in the induced drag
coefficient, assuming an elliptical lift distribution and that each degree of washout reduces induced
drag by 2%.
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Solution:
Change in washout = 3° - 2° = 1°
Induced drag reduction = 1° × 2% = 2%
Answer: a) 2% decrease
34. The aircraft's velocity is increased by 20% at the same altitude. Calculate the percentage change
in dynamic pressure using the equation: q = 1/2 ρV^2.
a) 20% increase
b) 32% increase
c) 44% increase
d) 56% increase
Solution:
New q / Old q = (1.2V)^2 / V^2 = 1.44
Percentage change = (1.44 - 1) × 100% = 44%
Answer: c) 44% increase
35. The fuselage length is increased by 5%. What is the percentage change in the aircraft's pitch
moment of inertia, assuming it is proportional to the square of the fuselage length?
a) 5% increase
b) 7.7% increase
c) 10.3% increase
d) 12.9% increase
Solution:
New inertia / Old inertia = (1.05 × length)^2 / length^2 = 1.1025
Percentage change = (1.1025 - 1) × 100% = 10.25%
Answer: c) 10.3% increase
Winglets are added to an aircraft, reducing the effective aspect ratio by 20%. What is the percentage
change in the induced drag factor?
a) 10.5% decrease
b) 13.6% decrease
c) 16.7% decrease
d) 19.8% decrease
Answer: c) 16.7% decrease
11. The parasite drag coefficient decreases by 10% and the induced drag coefficient increases by 5%.
What can be said about the change in lift-to-drag ratio?
a) It always increases
b) It always decreases
c) It remains the same
d) It depends on the original lift and drag coefficients
Answer: d) It depends on the original lift and drag coefficients
12. If the dihedral angle of a wing is increased from 3° to 5°, what is the percentage change in the
lateral stability derivative?
a) 33.3% increase
b) 50.0% increase
c) 66.7% increase
d) 83.3% increase
Answer: c) 66.7% increase
13. An aircraft's weight is reduced by 8% and the wing area is increased by 5%. What is the
percentage change in wing loading?
a) 8.7% decrease
b) 10.5% decrease
c) 12.4% decrease
d) 14.3% decrease
Answer: c) 12.4% decrease
14. The wing sweep is increased from 0° to 30°. What is the approximate percentage change in the
critical Mach number?
a) 10.5% increase
b) 15.5% increase
c) 20.5% increase
d) 25.5% increase
Answer: b) 15.5% increase
15. If the aspect ratio of a wing is doubled, what is the percentage change in the lift curve slope?
a) 25.0% increase
b) 33.3% increase
c) 41.7% increase
d) 50.0% increase
Answer: b) 33.3% increase
16. An aircraft's weight increases by 20% and its velocity decreases by 10%. What is the percentage
change in the lift coefficient required for level flight?
a) 32.5% increase
b) 40.3% increase
c) 48.1% increase
d) 55.9% increase
Answer: c) 48.1% increase
17. The chord of a wing is increased by 10% while maintaining the same wingspan. What is the
percentage change in the wing's wetted area?
a) 5% increase
b) 10% increase
c) 15% increase
d) 20% increase
Answer: b) 10% increase
18. The tail incidence angle is changed from 2° to -1°. What is the change in the aircraft's pitch trim?
a) 1° nose-down
b) 2° nose-down
c) 3° nose-down
d) 4° nose-down
Answer: c) 3° nose-down
19. The wingspan is increased by 25% while maintaining the same wing area. What is the percentage
change in the induced drag coefficient?
a) 24% decrease
b) 30% decrease
c) 36% decrease
d) 42% decrease
Answer: c) 36% decrease
20. If the aileron area is increased by 15%, what is the approximate percentage change in the
aircraft's roll rate?
a) 10% increase
b) 15% increase
c) 20% increase
d) 25% increase
Answer: b) 15% increase
21. The wing's quarter-chord sweep angle is increased from 20° to 30°. What is the approximate
percentage change in the wing's critical Mach number?
a) 5.7% increase
b) 7.7% increase
c) 9.7% increase
d) 11.7% increase
Answer: b) 7.7% increase
22. The center of gravity is moved forward by 5% of the mean aerodynamic chord. What is the
change in the static margin?
a) 3% increase
b) 4% increase
c) 5% increase
d) 6% increase
Answer: c) 5% increase
23. The flap deflection angle is increased from 20° to 30°. Which statement is true about the change
in maximum lift coefficient?
a) It always increases by 10%
b) It always increases by 20%
c) It always decreases
d) It depends on the airfoil and flap type
Answer: d) It depends on the airfoil and flap type
24. If the winglet height is increased by 20%, what is the approximate percentage reduction in
induced drag?
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Answer: b) 4% decrease (assuming 20% effectiveness)
25. The wing aspect ratio is increased from 7 to 9. What is the approximate percentage change in the
Oswald efficiency factor?
a) 4.7% increase
b) 5.7% increase
c) 6.7% increase
d) 7.7% increase
Answer: c) 6.7% increase (assuming typical relationship)
26. The vertical tail area is increased by 12%. What is the percentage change in the aircraft's
directional stability?
a) 8% increase
b) 10% increase
c) 12% increase
d) 14% increase
Answer: c) 12% increase (assuming linear relationship)
27. An aircraft's weight is reduced by 10% and the wing area is decreased by 5%. Calculate the
percentage change in the stall speed using the equation: Vs ∝ √(W/S).
a) 1.3% decrease
b) 2.6% decrease
c) 3.9% decrease
d) 5.2% decrease
Solution:
Vs_new / Vs_old = √[(0.9W / 0.95S) / (W/S)] = √(0.9/0.95) = 0.974
Percentage change = (0.974 - 1) × 100% = -2.6%
Answer: b) 2.6% decrease
28. Both the lift and drag coefficients increase by 5%. Calculate the new lift-to-drag ratio.
a) 5% increase
b) No change
c) 5% decrease
d) Cannot be determined without original values
Solution:
New L/D = (1.05CL) / (1.05CD) = CL / CD = Original L/D
Answer: b) No change
29. The wingspan is increased by 15% while maintaining the same lift distribution. What is the
percentage change in the wing root bending moment?
a) 15% increase
b) 23.7% increase
c) 32.3% increase
d) 41% increase
Solution:
Bending moment ∝ span^2
New moment / Old moment = (1.15 × span)^2 / span^2 = 1.3225
Percentage change = (1.3225 - 1) × 100% = 32.25%
Answer: c) 32.3% increase
30. The horizontal tail volume coefficient is increased from 0.7 to 0.8. What is the percentage change
in the aircraft's pitch damping?
a) 10% increase
b) 12.5% increase
c) 14.3% increase
d) 16.7% increase
Solution:
Percentage change = (0.8 - 0.7) / 0.7 × 100% = 14.3%
Answer: c) 14.3% increase
31. The wing span is increased by 10% and the wing area is decreased by 5%. Calculate the
percentage change in aspect ratio using the equation: AR = b^2 / S.
a) 20.5% increase
b) 23.7% increase
c) 27.3% increase
d) 31.6% increase
Solution:
New AR / Old AR = (1.1b)^2 / (0.95S) / (b^2/S) = 1.21 / 0.95 = 1.273
Percentage change = (1.273 - 1) × 100% = 27.3%
Answer: c) 27.3% increase
32. The wingspan is increased by 8%. What is the percentage change in the aircraft's roll inertia,
given that roll inertia is proportional to the square of the wingspan?
a) 8% increase
b) 12.3% increase
c) 16.6% increase
d) 20.9% increase
Solution:
New inertia / Old inertia = (1.08 × span)^2 / span^2 = 1.1664
Percentage change = (1.1664 - 1) × 100% = 16.64%
Answer: c) 16.6% increase
33. The wing twist (washout) is increased from 2° to 3°. Estimate the change in the induced drag
coefficient, assuming an elliptical lift distribution and that each degree of washout reduces induced
drag by 2%.
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Solution:
Change in washout = 3° - 2° = 1°
Induced drag reduction = 1° × 2% = 2%
Answer: a) 2% decrease
34. The aircraft's velocity is increased by 20% at the same altitude. Calculate the percentage change
in dynamic pressure using the equation: q = 1/2 ρV^2.
a) 20% increase
b) 32% increase
c) 44% increase
d) 56% increase
Solution:
New q / Old q = (1.2V)^2 / V^2 = 1.44
Percentage change = (1.44 - 1) × 100% = 44%
Answer: c) 44% increase
35. The fuselage length is increased by 5%. What is the percentage change in the aircraft's pitch
moment of inertia, assuming it is proportional to the square of the fuselage length?
a) 5% increase
b) 7.7% increase
c) 10.3% increase
d) 12.9% increase
Solution:
New inertia / Old inertia = (1.05 × length)^2 / length^2 = 1.1025
Percentage change = (1.1025 - 1) × 100% = 10.25%
Answer: c) 10.3% increase
Winglets are added to an aircraft, reducing the effective aspect ratio by 20%. What is the percentage
change in the induced drag factor?
a) 10.5% decrease
b) 13.6% decrease
c) 16.7% decrease
d) 19.8% decrease
Answer: c) 16.7% decrease
11. The parasite drag coefficient decreases by 10% and the induced drag coefficient increases by 5%.
What can be said about the change in lift-to-drag ratio?
a) It always increases
b) It always decreases
c) It remains the same
d) It depends on the original lift and drag coefficients
Answer: d) It depends on the original lift and drag coefficients
12. If the dihedral angle of a wing is increased from 3° to 5°, what is the percentage change in the
lateral stability derivative?
a) 33.3% increase
b) 50.0% increase
c) 66.7% increase
d) 83.3% increase
Answer: c) 66.7% increase
13. An aircraft's weight is reduced by 8% and the wing area is increased by 5%. What is the
percentage change in wing loading?
a) 8.7% decrease
b) 10.5% decrease
c) 12.4% decrease
d) 14.3% decrease
Answer: c) 12.4% decrease
14. The wing sweep is increased from 0° to 30°. What is the approximate percentage change in the
critical Mach number?
a) 10.5% increase
b) 15.5% increase
c) 20.5% increase
d) 25.5% increase
Answer: b) 15.5% increase
15. If the aspect ratio of a wing is doubled, what is the percentage change in the lift curve slope?
a) 25.0% increase
b) 33.3% increase
c) 41.7% increase
d) 50.0% increase
Answer: b) 33.3% increase
16. An aircraft's weight increases by 20% and its velocity decreases by 10%. What is the percentage
change in the lift coefficient required for level flight?
a) 32.5% increase
b) 40.3% increase
c) 48.1% increase
d) 55.9% increase
Answer: c) 48.1% increase
17. The chord of a wing is increased by 10% while maintaining the same wingspan. What is the
percentage change in the wing's wetted area?
a) 5% increase
b) 10% increase
c) 15% increase
d) 20% increase
Answer: b) 10% increase
18. The tail incidence angle is changed from 2° to -1°. What is the change in the aircraft's pitch trim?
a) 1° nose-down
b) 2° nose-down
c) 3° nose-down
d) 4° nose-down
Answer: c) 3° nose-down
19. The wingspan is increased by 25% while maintaining the same wing area. What is the percentage
change in the induced drag coefficient?
a) 24% decrease
b) 30% decrease
c) 36% decrease
d) 42% decrease
Answer: c) 36% decrease
20. If the aileron area is increased by 15%, what is the approximate percentage change in the
aircraft's roll rate?
a) 10% increase
b) 15% increase
c) 20% increase
d) 25% increase
Answer: b) 15% increase
21. The wing's quarter-chord sweep angle is increased from 20° to 30°. What is the approximate
percentage change in the wing's critical Mach number?
a) 5.7% increase
b) 7.7% increase
c) 9.7% increase
d) 11.7% increase
Answer: b) 7.7% increase
22. The center of gravity is moved forward by 5% of the mean aerodynamic chord. What is the
change in the static margin?
a) 3% increase
b) 4% increase
c) 5% increase
d) 6% increase
Answer: c) 5% increase
23. The flap deflection angle is increased from 20° to 30°. Which statement is true about the change
in maximum lift coefficient?
a) It always increases by 10%
b) It always increases by 20%
c) It always decreases
d) It depends on the airfoil and flap type
Answer: d) It depends on the airfoil and flap type
24. If the winglet height is increased by 20%, what is the approximate percentage reduction in
induced drag?
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Answer: b) 4% decrease (assuming 20% effectiveness)
25. The wing aspect ratio is increased from 7 to 9. What is the approximate percentage change in the
Oswald efficiency factor?
a) 4.7% increase
b) 5.7% increase
c) 6.7% increase
d) 7.7% increase
Answer: c) 6.7% increase (assuming typical relationship)
26. The vertical tail area is increased by 12%. What is the percentage change in the aircraft's
directional stability?
a) 8% increase
b) 10% increase
c) 12% increase
d) 14% increase
Answer: c) 12% increase (assuming linear relationship)
27. An aircraft's weight is reduced by 10% and the wing area is decreased by 5%. Calculate the
percentage change in the stall speed using the equation: Vs ∝ √(W/S).
a) 1.3% decrease
b) 2.6% decrease
c) 3.9% decrease
d) 5.2% decrease
Solution:
Vs_new / Vs_old = √[(0.9W / 0.95S) / (W/S)] = √(0.9/0.95) = 0.974
Percentage change = (0.974 - 1) × 100% = -2.6%
Answer: b) 2.6% decrease
28. Both the lift and drag coefficients increase by 5%. Calculate the new lift-to-drag ratio.
a) 5% increase
b) No change
c) 5% decrease
d) Cannot be determined without original values
Solution:
New L/D = (1.05CL) / (1.05CD) = CL / CD = Original L/D
Answer: b) No change
29. The wingspan is increased by 15% while maintaining the same lift distribution. What is the
percentage change in the wing root bending moment?
a) 15% increase
b) 23.7% increase
c) 32.3% increase
d) 41% increase
Solution:
Bending moment ∝ span^2
New moment / Old moment = (1.15 × span)^2 / span^2 = 1.3225
Percentage change = (1.3225 - 1) × 100% = 32.25%
Answer: c) 32.3% increase
30. The horizontal tail volume coefficient is increased from 0.7 to 0.8. What is the percentage change
in the aircraft's pitch damping?
a) 10% increase
b) 12.5% increase
c) 14.3% increase
d) 16.7% increase
Solution:
Percentage change = (0.8 - 0.7) / 0.7 × 100% = 14.3%
Answer: c) 14.3% increase
31. The wing span is increased by 10% and the wing area is decreased by 5%. Calculate the
percentage change in aspect ratio using the equation: AR = b^2 / S.
a) 20.5% increase
b) 23.7% increase
c) 27.3% increase
d) 31.6% increase
Solution:
New AR / Old AR = (1.1b)^2 / (0.95S) / (b^2/S) = 1.21 / 0.95 = 1.273
Percentage change = (1.273 - 1) × 100% = 27.3%
Answer: c) 27.3% increase
32. The wingspan is increased by 8%. What is the percentage change in the aircraft's roll inertia,
given that roll inertia is proportional to the square of the wingspan?
a) 8% increase
b) 12.3% increase
c) 16.6% increase
d) 20.9% increase
Solution:
New inertia / Old inertia = (1.08 × span)^2 / span^2 = 1.1664
Percentage change = (1.1664 - 1) × 100% = 16.64%
Answer: c) 16.6% increase
33. The wing twist (washout) is increased from 2° to 3°. Estimate the change in the induced drag
coefficient, assuming an elliptical lift distribution and that each degree of washout reduces induced
drag by 2%.
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Solution:
Change in washout = 3° - 2° = 1°
Induced drag reduction = 1° × 2% = 2%
Answer: a) 2% decrease
34. The aircraft's velocity is increased by 20% at the same altitude. Calculate the percentage change
in dynamic pressure using the equation: q = 1/2 ρV^2.
a) 20% increase
b) 32% increase
c) 44% increase
d) 56% increase
Solution:
New q / Old q = (1.2V)^2 / V^2 = 1.44
Percentage change = (1.44 - 1) × 100% = 44%
Answer: c) 44% increase
35. The fuselage length is increased by 5%. What is the percentage change in the aircraft's pitch
moment of inertia, assuming it is proportional to the square of the fuselage length?
a) 5% increase
b) 7.7% increase
c) 10.3% increase
d) 12.9% increase
Solution:
New inertia / Old inertia = (1.05 × length)^2 / length^2 = 1.1025
Percentage change = (1.1025 - 1) × 100% = 10.25%
Answer: c) 10.3% increase
Winglets are added to an aircraft, reducing the effective aspect ratio by 20%. What is the percentage
change in the induced drag factor?
a) 10.5% decrease
b) 13.6% decrease
c) 16.7% decrease
d) 19.8% decrease
Answer: c) 16.7% decrease
11. The parasite drag coefficient decreases by 10% and the induced drag coefficient increases by 5%.
What can be said about the change in lift-to-drag ratio?
a) It always increases
b) It always decreases
c) It remains the same
d) It depends on the original lift and drag coefficients
Answer: d) It depends on the original lift and drag coefficients
12. If the dihedral angle of a wing is increased from 3° to 5°, what is the percentage change in the
lateral stability derivative?
a) 33.3% increase
b) 50.0% increase
c) 66.7% increase
d) 83.3% increase
Answer: c) 66.7% increase
13. An aircraft's weight is reduced by 8% and the wing area is increased by 5%. What is the
percentage change in wing loading?
a) 8.7% decrease
b) 10.5% decrease
c) 12.4% decrease
d) 14.3% decrease
Answer: c) 12.4% decrease
14. The wing sweep is increased from 0° to 30°. What is the approximate percentage change in the
critical Mach number?
a) 10.5% increase
b) 15.5% increase
c) 20.5% increase
d) 25.5% increase
Answer: b) 15.5% increase
15. If the aspect ratio of a wing is doubled, what is the percentage change in the lift curve slope?
a) 25.0% increase
b) 33.3% increase
c) 41.7% increase
d) 50.0% increase
Answer: b) 33.3% increase
16. An aircraft's weight increases by 20% and its velocity decreases by 10%. What is the percentage
change in the lift coefficient required for level flight?
a) 32.5% increase
b) 40.3% increase
c) 48.1% increase
d) 55.9% increase
Answer: c) 48.1% increase
17. The chord of a wing is increased by 10% while maintaining the same wingspan. What is the
percentage change in the wing's wetted area?
a) 5% increase
b) 10% increase
c) 15% increase
d) 20% increase
Answer: b) 10% increase
18. The tail incidence angle is changed from 2° to -1°. What is the change in the aircraft's pitch trim?
a) 1° nose-down
b) 2° nose-down
c) 3° nose-down
d) 4° nose-down
Answer: c) 3° nose-down
19. The wingspan is increased by 25% while maintaining the same wing area. What is the percentage
change in the induced drag coefficient?
a) 24% decrease
b) 30% decrease
c) 36% decrease
d) 42% decrease
Answer: c) 36% decrease
20. If the aileron area is increased by 15%, what is the approximate percentage change in the
aircraft's roll rate?
a) 10% increase
b) 15% increase
c) 20% increase
d) 25% increase
Answer: b) 15% increase
21. The wing's quarter-chord sweep angle is increased from 20° to 30°. What is the approximate
percentage change in the wing's critical Mach number?
a) 5.7% increase
b) 7.7% increase
c) 9.7% increase
d) 11.7% increase
Answer: b) 7.7% increase
22. The center of gravity is moved forward by 5% of the mean aerodynamic chord. What is the
change in the static margin?
a) 3% increase
b) 4% increase
c) 5% increase
d) 6% increase
Answer: c) 5% increase
23. The flap deflection angle is increased from 20° to 30°. Which statement is true about the change
in maximum lift coefficient?
a) It always increases by 10%
b) It always increases by 20%
c) It always decreases
d) It depends on the airfoil and flap type
Answer: d) It depends on the airfoil and flap type
24. If the winglet height is increased by 20%, what is the approximate percentage reduction in
induced drag?
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Answer: b) 4% decrease (assuming 20% effectiveness)
25. The wing aspect ratio is increased from 7 to 9. What is the approximate percentage change in the
Oswald efficiency factor?
a) 4.7% increase
b) 5.7% increase
c) 6.7% increase
d) 7.7% increase
Answer: c) 6.7% increase (assuming typical relationship)
26. The vertical tail area is increased by 12%. What is the percentage change in the aircraft's
directional stability?
a) 8% increase
b) 10% increase
c) 12% increase
d) 14% increase
Answer: c) 12% increase (assuming linear relationship)
27. An aircraft's weight is reduced by 10% and the wing area is decreased by 5%. Calculate the
percentage change in the stall speed using the equation: Vs ∝ √(W/S).
a) 1.3% decrease
b) 2.6% decrease
c) 3.9% decrease
d) 5.2% decrease
Solution:
Vs_new / Vs_old = √[(0.9W / 0.95S) / (W/S)] = √(0.9/0.95) = 0.974
Percentage change = (0.974 - 1) × 100% = -2.6%
Answer: b) 2.6% decrease
28. Both the lift and drag coefficients increase by 5%. Calculate the new lift-to-drag ratio.
a) 5% increase
b) No change
c) 5% decrease
d) Cannot be determined without original values
Solution:
New L/D = (1.05CL) / (1.05CD) = CL / CD = Original L/D
Answer: b) No change
29. The wingspan is increased by 15% while maintaining the same lift distribution. What is the
percentage change in the wing root bending moment?
a) 15% increase
b) 23.7% increase
c) 32.3% increase
d) 41% increase
Solution:
Bending moment ∝ span^2
New moment / Old moment = (1.15 × span)^2 / span^2 = 1.3225
Percentage change = (1.3225 - 1) × 100% = 32.25%
Answer: c) 32.3% increase
30. The horizontal tail volume coefficient is increased from 0.7 to 0.8. What is the percentage change
in the aircraft's pitch damping?
a) 10% increase
b) 12.5% increase
c) 14.3% increase
d) 16.7% increase
Solution:
Percentage change = (0.8 - 0.7) / 0.7 × 100% = 14.3%
Answer: c) 14.3% increase
31. The wing span is increased by 10% and the wing area is decreased by 5%. Calculate the
percentage change in aspect ratio using the equation: AR = b^2 / S.
a) 20.5% increase
b) 23.7% increase
c) 27.3% increase
d) 31.6% increase
Solution:
New AR / Old AR = (1.1b)^2 / (0.95S) / (b^2/S) = 1.21 / 0.95 = 1.273
Percentage change = (1.273 - 1) × 100% = 27.3%
Answer: c) 27.3% increase
32. The wingspan is increased by 8%. What is the percentage change in the aircraft's roll inertia,
given that roll inertia is proportional to the square of the wingspan?
a) 8% increase
b) 12.3% increase
c) 16.6% increase
d) 20.9% increase
Solution:
New inertia / Old inertia = (1.08 × span)^2 / span^2 = 1.1664
Percentage change = (1.1664 - 1) × 100% = 16.64%
Answer: c) 16.6% increase
33. The wing twist (washout) is increased from 2° to 3°. Estimate the change in the induced drag
coefficient, assuming an elliptical lift distribution and that each degree of washout reduces induced
drag by 2%.
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Solution:
Change in washout = 3° - 2° = 1°
Induced drag reduction = 1° × 2% = 2%
Answer: a) 2% decrease
34. The aircraft's velocity is increased by 20% at the same altitude. Calculate the percentage change
in dynamic pressure using the equation: q = 1/2 ρV^2.
a) 20% increase
b) 32% increase
c) 44% increase
d) 56% increase
Solution:
New q / Old q = (1.2V)^2 / V^2 = 1.44
Percentage change = (1.44 - 1) × 100% = 44%
Answer: c) 44% increase
35. The fuselage length is increased by 5%. What is the percentage change in the aircraft's pitch
moment of inertia, assuming it is proportional to the square of the fuselage length?
a) 5% increase
b) 7.7% increase
c) 10.3% increase
d) 12.9% increase
Solution:
New inertia / Old inertia = (1.05 × length)^2 / length^2 = 1.1025
Percentage change = (1.1025 - 1) × 100% = 10.25%
Answer: c) 10.3% increase
Winglets are added to an aircraft, reducing the effective aspect ratio by 20%. What is the percentage
change in the induced drag factor?
a) 10.5% decrease
b) 13.6% decrease
c) 16.7% decrease
d) 19.8% decrease
Answer: c) 16.7% decrease
11. The parasite drag coefficient decreases by 10% and the induced drag coefficient increases by 5%.
What can be said about the change in lift-to-drag ratio?
a) It always increases
b) It always decreases
c) It remains the same
d) It depends on the original lift and drag coefficients
Answer: d) It depends on the original lift and drag coefficients
12. If the dihedral angle of a wing is increased from 3° to 5°, what is the percentage change in the
lateral stability derivative?
a) 33.3% increase
b) 50.0% increase
c) 66.7% increase
d) 83.3% increase
Answer: c) 66.7% increase
13. An aircraft's weight is reduced by 8% and the wing area is increased by 5%. What is the
percentage change in wing loading?
a) 8.7% decrease
b) 10.5% decrease
c) 12.4% decrease
d) 14.3% decrease
Answer: c) 12.4% decrease
14. The wing sweep is increased from 0° to 30°. What is the approximate percentage change in the
critical Mach number?
a) 10.5% increase
b) 15.5% increase
c) 20.5% increase
d) 25.5% increase
Answer: b) 15.5% increase
15. If the aspect ratio of a wing is doubled, what is the percentage change in the lift curve slope?
a) 25.0% increase
b) 33.3% increase
c) 41.7% increase
d) 50.0% increase
Answer: b) 33.3% increase
16. An aircraft's weight increases by 20% and its velocity decreases by 10%. What is the percentage
change in the lift coefficient required for level flight?
a) 32.5% increase
b) 40.3% increase
c) 48.1% increase
d) 55.9% increase
Answer: c) 48.1% increase
17. The chord of a wing is increased by 10% while maintaining the same wingspan. What is the
percentage change in the wing's wetted area?
a) 5% increase
b) 10% increase
c) 15% increase
d) 20% increase
Answer: b) 10% increase
18. The tail incidence angle is changed from 2° to -1°. What is the change in the aircraft's pitch trim?
a) 1° nose-down
b) 2° nose-down
c) 3° nose-down
d) 4° nose-down
Answer: c) 3° nose-down
19. The wingspan is increased by 25% while maintaining the same wing area. What is the percentage
change in the induced drag coefficient?
a) 24% decrease
b) 30% decrease
c) 36% decrease
d) 42% decrease
Answer: c) 36% decrease
20. If the aileron area is increased by 15%, what is the approximate percentage change in the
aircraft's roll rate?
a) 10% increase
b) 15% increase
c) 20% increase
d) 25% increase
Answer: b) 15% increase
21. The wing's quarter-chord sweep angle is increased from 20° to 30°. What is the approximate
percentage change in the wing's critical Mach number?
a) 5.7% increase
b) 7.7% increase
c) 9.7% increase
d) 11.7% increase
Answer: b) 7.7% increase
22. The center of gravity is moved forward by 5% of the mean aerodynamic chord. What is the
change in the static margin?
a) 3% increase
b) 4% increase
c) 5% increase
d) 6% increase
Answer: c) 5% increase
23. The flap deflection angle is increased from 20° to 30°. Which statement is true about the change
in maximum lift coefficient?
a) It always increases by 10%
b) It always increases by 20%
c) It always decreases
d) It depends on the airfoil and flap type
Answer: d) It depends on the airfoil and flap type
24. If the winglet height is increased by 20%, what is the approximate percentage reduction in
induced drag?
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Answer: b) 4% decrease (assuming 20% effectiveness)
25. The wing aspect ratio is increased from 7 to 9. What is the approximate percentage change in the
Oswald efficiency factor?
a) 4.7% increase
b) 5.7% increase
c) 6.7% increase
d) 7.7% increase
Answer: c) 6.7% increase (assuming typical relationship)
26. The vertical tail area is increased by 12%. What is the percentage change in the aircraft's
directional stability?
a) 8% increase
b) 10% increase
c) 12% increase
d) 14% increase
Answer: c) 12% increase (assuming linear relationship)
27. An aircraft's weight is reduced by 10% and the wing area is decreased by 5%. Calculate the
percentage change in the stall speed using the equation: Vs ∝ √(W/S).
a) 1.3% decrease
b) 2.6% decrease
c) 3.9% decrease
d) 5.2% decrease
Solution:
Vs_new / Vs_old = √[(0.9W / 0.95S) / (W/S)] = √(0.9/0.95) = 0.974
Percentage change = (0.974 - 1) × 100% = -2.6%
Answer: b) 2.6% decrease
28. Both the lift and drag coefficients increase by 5%. Calculate the new lift-to-drag ratio.
a) 5% increase
b) No change
c) 5% decrease
d) Cannot be determined without original values
Solution:
New L/D = (1.05CL) / (1.05CD) = CL / CD = Original L/D
Answer: b) No change
29. The wingspan is increased by 15% while maintaining the same lift distribution. What is the
percentage change in the wing root bending moment?
a) 15% increase
b) 23.7% increase
c) 32.3% increase
d) 41% increase
Solution:
Bending moment ∝ span^2
New moment / Old moment = (1.15 × span)^2 / span^2 = 1.3225
Percentage change = (1.3225 - 1) × 100% = 32.25%
Answer: c) 32.3% increase
30. The horizontal tail volume coefficient is increased from 0.7 to 0.8. What is the percentage change
in the aircraft's pitch damping?
a) 10% increase
b) 12.5% increase
c) 14.3% increase
d) 16.7% increase
Solution:
Percentage change = (0.8 - 0.7) / 0.7 × 100% = 14.3%
Answer: c) 14.3% increase
31. The wing span is increased by 10% and the wing area is decreased by 5%. Calculate the
percentage change in aspect ratio using the equation: AR = b^2 / S.
a) 20.5% increase
b) 23.7% increase
c) 27.3% increase
d) 31.6% increase
Solution:
New AR / Old AR = (1.1b)^2 / (0.95S) / (b^2/S) = 1.21 / 0.95 = 1.273
Percentage change = (1.273 - 1) × 100% = 27.3%
Answer: c) 27.3% increase
32. The wingspan is increased by 8%. What is the percentage change in the aircraft's roll inertia,
given that roll inertia is proportional to the square of the wingspan?
a) 8% increase
b) 12.3% increase
c) 16.6% increase
d) 20.9% increase
Solution:
New inertia / Old inertia = (1.08 × span)^2 / span^2 = 1.1664
Percentage change = (1.1664 - 1) × 100% = 16.64%
Answer: c) 16.6% increase
33. The wing twist (washout) is increased from 2° to 3°. Estimate the change in the induced drag
coefficient, assuming an elliptical lift distribution and that each degree of washout reduces induced
drag by 2%.
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Solution:
Change in washout = 3° - 2° = 1°
Induced drag reduction = 1° × 2% = 2%
Answer: a) 2% decrease
34. The aircraft's velocity is increased by 20% at the same altitude. Calculate the percentage change
in dynamic pressure using the equation: q = 1/2 ρV^2.
a) 20% increase
b) 32% increase
c) 44% increase
d) 56% increase
Solution:
New q / Old q = (1.2V)^2 / V^2 = 1.44
Percentage change = (1.44 - 1) × 100% = 44%
Answer: c) 44% increase
35. The fuselage length is increased by 5%. What is the percentage change in the aircraft's pitch
moment of inertia, assuming it is proportional to the square of the fuselage length?
a) 5% increase
b) 7.7% increase
c) 10.3% increase
d) 12.9% increase
Solution:
New inertia / Old inertia = (1.05 × length)^2 / length^2 = 1.1025
Percentage change = (1.1025 - 1) × 100% = 10.25%
Answer: c) 10.3% increase
Winglets are added to an aircraft, reducing the effective aspect ratio by 20%. What is the percentage
change in the induced drag factor?
a) 10.5% decrease
b) 13.6% decrease
c) 16.7% decrease
d) 19.8% decrease
Answer: c) 16.7% decrease
11. The parasite drag coefficient decreases by 10% and the induced drag coefficient increases by 5%.
What can be said about the change in lift-to-drag ratio?
a) It always increases
b) It always decreases
c) It remains the same
d) It depends on the original lift and drag coefficients
Answer: d) It depends on the original lift and drag coefficients
12. If the dihedral angle of a wing is increased from 3° to 5°, what is the percentage change in the
lateral stability derivative?
a) 33.3% increase
b) 50.0% increase
c) 66.7% increase
d) 83.3% increase
Answer: c) 66.7% increase
13. An aircraft's weight is reduced by 8% and the wing area is increased by 5%. What is the
percentage change in wing loading?
a) 8.7% decrease
b) 10.5% decrease
c) 12.4% decrease
d) 14.3% decrease
Answer: c) 12.4% decrease
14. The wing sweep is increased from 0° to 30°. What is the approximate percentage change in the
critical Mach number?
a) 10.5% increase
b) 15.5% increase
c) 20.5% increase
d) 25.5% increase
Answer: b) 15.5% increase
15. If the aspect ratio of a wing is doubled, what is the percentage change in the lift curve slope?
a) 25.0% increase
b) 33.3% increase
c) 41.7% increase
d) 50.0% increase
Answer: b) 33.3% increase
16. An aircraft's weight increases by 20% and its velocity decreases by 10%. What is the percentage
change in the lift coefficient required for level flight?
a) 32.5% increase
b) 40.3% increase
c) 48.1% increase
d) 55.9% increase
Answer: c) 48.1% increase
17. The chord of a wing is increased by 10% while maintaining the same wingspan. What is the
percentage change in the wing's wetted area?
a) 5% increase
b) 10% increase
c) 15% increase
d) 20% increase
Answer: b) 10% increase
18. The tail incidence angle is changed from 2° to -1°. What is the change in the aircraft's pitch trim?
a) 1° nose-down
b) 2° nose-down
c) 3° nose-down
d) 4° nose-down
Answer: c) 3° nose-down
19. The wingspan is increased by 25% while maintaining the same wing area. What is the percentage
change in the induced drag coefficient?
a) 24% decrease
b) 30% decrease
c) 36% decrease
d) 42% decrease
Answer: c) 36% decrease
20. If the aileron area is increased by 15%, what is the approximate percentage change in the
aircraft's roll rate?
a) 10% increase
b) 15% increase
c) 20% increase
d) 25% increase
Answer: b) 15% increase
21. The wing's quarter-chord sweep angle is increased from 20° to 30°. What is the approximate
percentage change in the wing's critical Mach number?
a) 5.7% increase
b) 7.7% increase
c) 9.7% increase
d) 11.7% increase
Answer: b) 7.7% increase
22. The center of gravity is moved forward by 5% of the mean aerodynamic chord. What is the
change in the static margin?
a) 3% increase
b) 4% increase
c) 5% increase
d) 6% increase
Answer: c) 5% increase
23. The flap deflection angle is increased from 20° to 30°. Which statement is true about the change
in maximum lift coefficient?
a) It always increases by 10%
b) It always increases by 20%
c) It always decreases
d) It depends on the airfoil and flap type
Answer: d) It depends on the airfoil and flap type
24. If the winglet height is increased by 20%, what is the approximate percentage reduction in
induced drag?
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Answer: b) 4% decrease (assuming 20% effectiveness)
25. The wing aspect ratio is increased from 7 to 9. What is the approximate percentage change in the
Oswald efficiency factor?
a) 4.7% increase
b) 5.7% increase
c) 6.7% increase
d) 7.7% increase
Answer: c) 6.7% increase (assuming typical relationship)
26. The vertical tail area is increased by 12%. What is the percentage change in the aircraft's
directional stability?
a) 8% increase
b) 10% increase
c) 12% increase
d) 14% increase
Answer: c) 12% increase (assuming linear relationship)
27. An aircraft's weight is reduced by 10% and the wing area is decreased by 5%. Calculate the
percentage change in the stall speed using the equation: Vs ∝ √(W/S).
a) 1.3% decrease
b) 2.6% decrease
c) 3.9% decrease
d) 5.2% decrease
Solution:
Vs_new / Vs_old = √[(0.9W / 0.95S) / (W/S)] = √(0.9/0.95) = 0.974
Percentage change = (0.974 - 1) × 100% = -2.6%
Answer: b) 2.6% decrease
28. Both the lift and drag coefficients increase by 5%. Calculate the new lift-to-drag ratio.
a) 5% increase
b) No change
c) 5% decrease
d) Cannot be determined without original values
Solution:
New L/D = (1.05CL) / (1.05CD) = CL / CD = Original L/D
Answer: b) No change
29. The wingspan is increased by 15% while maintaining the same lift distribution. What is the
percentage change in the wing root bending moment?
a) 15% increase
b) 23.7% increase
c) 32.3% increase
d) 41% increase
Solution:
Bending moment ∝ span^2
New moment / Old moment = (1.15 × span)^2 / span^2 = 1.3225
Percentage change = (1.3225 - 1) × 100% = 32.25%
Answer: c) 32.3% increase
30. The horizontal tail volume coefficient is increased from 0.7 to 0.8. What is the percentage change
in the aircraft's pitch damping?
a) 10% increase
b) 12.5% increase
c) 14.3% increase
d) 16.7% increase
Solution:
Percentage change = (0.8 - 0.7) / 0.7 × 100% = 14.3%
Answer: c) 14.3% increase
31. The wing span is increased by 10% and the wing area is decreased by 5%. Calculate the
percentage change in aspect ratio using the equation: AR = b^2 / S.
a) 20.5% increase
b) 23.7% increase
c) 27.3% increase
d) 31.6% increase
Solution:
New AR / Old AR = (1.1b)^2 / (0.95S) / (b^2/S) = 1.21 / 0.95 = 1.273
Percentage change = (1.273 - 1) × 100% = 27.3%
Answer: c) 27.3% increase
32. The wingspan is increased by 8%. What is the percentage change in the aircraft's roll inertia,
given that roll inertia is proportional to the square of the wingspan?
a) 8% increase
b) 12.3% increase
c) 16.6% increase
d) 20.9% increase
Solution:
New inertia / Old inertia = (1.08 × span)^2 / span^2 = 1.1664
Percentage change = (1.1664 - 1) × 100% = 16.64%
Answer: c) 16.6% increase
33. The wing twist (washout) is increased from 2° to 3°. Estimate the change in the induced drag
coefficient, assuming an elliptical lift distribution and that each degree of washout reduces induced
drag by 2%.
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Solution:
Change in washout = 3° - 2° = 1°
Induced drag reduction = 1° × 2% = 2%
Answer: a) 2% decrease
34. The aircraft's velocity is increased by 20% at the same altitude. Calculate the percentage change
in dynamic pressure using the equation: q = 1/2 ρV^2.
a) 20% increase
b) 32% increase
c) 44% increase
d) 56% increase
Solution:
New q / Old q = (1.2V)^2 / V^2 = 1.44
Percentage change = (1.44 - 1) × 100% = 44%
Answer: c) 44% increase
35. The fuselage length is increased by 5%. What is the percentage change in the aircraft's pitch
moment of inertia, assuming it is proportional to the square of the fuselage length?
a) 5% increase
b) 7.7% increase
c) 10.3% increase
d) 12.9% increase
Solution:
New inertia / Old inertia = (1.05 × length)^2 / length^2 = 1.1025
Percentage change = (1.1025 - 1) × 100% = 10.25%
Answer: c) 10.3% increase
Winglets are added to an aircraft, reducing the effective aspect ratio by 20%. What is the percentage
change in the induced drag factor?
a) 10.5% decrease
b) 13.6% decrease
c) 16.7% decrease
d) 19.8% decrease
Answer: c) 16.7% decrease
11. The parasite drag coefficient decreases by 10% and the induced drag coefficient increases by 5%.
What can be said about the change in lift-to-drag ratio?
a) It always increases
b) It always decreases
c) It remains the same
d) It depends on the original lift and drag coefficients
Answer: d) It depends on the original lift and drag coefficients
12. If the dihedral angle of a wing is increased from 3° to 5°, what is the percentage change in the
lateral stability derivative?
a) 33.3% increase
b) 50.0% increase
c) 66.7% increase
d) 83.3% increase
Answer: c) 66.7% increase
13. An aircraft's weight is reduced by 8% and the wing area is increased by 5%. What is the
percentage change in wing loading?
a) 8.7% decrease
b) 10.5% decrease
c) 12.4% decrease
d) 14.3% decrease
Answer: c) 12.4% decrease
14. The wing sweep is increased from 0° to 30°. What is the approximate percentage change in the
critical Mach number?
a) 10.5% increase
b) 15.5% increase
c) 20.5% increase
d) 25.5% increase
Answer: b) 15.5% increase
15. If the aspect ratio of a wing is doubled, what is the percentage change in the lift curve slope?
a) 25.0% increase
b) 33.3% increase
c) 41.7% increase
d) 50.0% increase
Answer: b) 33.3% increase
16. An aircraft's weight increases by 20% and its velocity decreases by 10%. What is the percentage
change in the lift coefficient required for level flight?
a) 32.5% increase
b) 40.3% increase
c) 48.1% increase
d) 55.9% increase
Answer: c) 48.1% increase
17. The chord of a wing is increased by 10% while maintaining the same wingspan. What is the
percentage change in the wing's wetted area?
a) 5% increase
b) 10% increase
c) 15% increase
d) 20% increase
Answer: b) 10% increase
18. The tail incidence angle is changed from 2° to -1°. What is the change in the aircraft's pitch trim?
a) 1° nose-down
b) 2° nose-down
c) 3° nose-down
d) 4° nose-down
Answer: c) 3° nose-down
19. The wingspan is increased by 25% while maintaining the same wing area. What is the percentage
change in the induced drag coefficient?
a) 24% decrease
b) 30% decrease
c) 36% decrease
d) 42% decrease
Answer: c) 36% decrease
20. If the aileron area is increased by 15%, what is the approximate percentage change in the
aircraft's roll rate?
a) 10% increase
b) 15% increase
c) 20% increase
d) 25% increase
Answer: b) 15% increase
21. The wing's quarter-chord sweep angle is increased from 20° to 30°. What is the approximate
percentage change in the wing's critical Mach number?
a) 5.7% increase
b) 7.7% increase
c) 9.7% increase
d) 11.7% increase
Answer: b) 7.7% increase
22. The center of gravity is moved forward by 5% of the mean aerodynamic chord. What is the
change in the static margin?
a) 3% increase
b) 4% increase
c) 5% increase
d) 6% increase
Answer: c) 5% increase
23. The flap deflection angle is increased from 20° to 30°. Which statement is true about the change
in maximum lift coefficient?
a) It always increases by 10%
b) It always increases by 20%
c) It always decreases
d) It depends on the airfoil and flap type
Answer: d) It depends on the airfoil and flap type
24. If the winglet height is increased by 20%, what is the approximate percentage reduction in
induced drag?
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Answer: b) 4% decrease (assuming 20% effectiveness)
25. The wing aspect ratio is increased from 7 to 9. What is the approximate percentage change in the
Oswald efficiency factor?
a) 4.7% increase
b) 5.7% increase
c) 6.7% increase
d) 7.7% increase
Answer: c) 6.7% increase (assuming typical relationship)
26. The vertical tail area is increased by 12%. What is the percentage change in the aircraft's
directional stability?
a) 8% increase
b) 10% increase
c) 12% increase
d) 14% increase
Answer: c) 12% increase (assuming linear relationship)
27. An aircraft's weight is reduced by 10% and the wing area is decreased by 5%. Calculate the
percentage change in the stall speed using the equation: Vs ∝ √(W/S).
a) 1.3% decrease
b) 2.6% decrease
c) 3.9% decrease
d) 5.2% decrease
Solution:
Vs_new / Vs_old = √[(0.9W / 0.95S) / (W/S)] = √(0.9/0.95) = 0.974
Percentage change = (0.974 - 1) × 100% = -2.6%
Answer: b) 2.6% decrease
28. Both the lift and drag coefficients increase by 5%. Calculate the new lift-to-drag ratio.
a) 5% increase
b) No change
c) 5% decrease
d) Cannot be determined without original values
Solution:
New L/D = (1.05CL) / (1.05CD) = CL / CD = Original L/D
Answer: b) No change
29. The wingspan is increased by 15% while maintaining the same lift distribution. What is the
percentage change in the wing root bending moment?
a) 15% increase
b) 23.7% increase
c) 32.3% increase
d) 41% increase
Solution:
Bending moment ∝ span^2
New moment / Old moment = (1.15 × span)^2 / span^2 = 1.3225
Percentage change = (1.3225 - 1) × 100% = 32.25%
Answer: c) 32.3% increase
30. The horizontal tail volume coefficient is increased from 0.7 to 0.8. What is the percentage change
in the aircraft's pitch damping?
a) 10% increase
b) 12.5% increase
c) 14.3% increase
d) 16.7% increase
Solution:
Percentage change = (0.8 - 0.7) / 0.7 × 100% = 14.3%
Answer: c) 14.3% increase
31. The wing span is increased by 10% and the wing area is decreased by 5%. Calculate the
percentage change in aspect ratio using the equation: AR = b^2 / S.
a) 20.5% increase
b) 23.7% increase
c) 27.3% increase
d) 31.6% increase
Solution:
New AR / Old AR = (1.1b)^2 / (0.95S) / (b^2/S) = 1.21 / 0.95 = 1.273
Percentage change = (1.273 - 1) × 100% = 27.3%
Answer: c) 27.3% increase
32. The wingspan is increased by 8%. What is the percentage change in the aircraft's roll inertia,
given that roll inertia is proportional to the square of the wingspan?
a) 8% increase
b) 12.3% increase
c) 16.6% increase
d) 20.9% increase
Solution:
New inertia / Old inertia = (1.08 × span)^2 / span^2 = 1.1664
Percentage change = (1.1664 - 1) × 100% = 16.64%
Answer: c) 16.6% increase
33. The wing twist (washout) is increased from 2° to 3°. Estimate the change in the induced drag
coefficient, assuming an elliptical lift distribution and that each degree of washout reduces induced
drag by 2%.
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Solution:
Change in washout = 3° - 2° = 1°
Induced drag reduction = 1° × 2% = 2%
Answer: a) 2% decrease
34. The aircraft's velocity is increased by 20% at the same altitude. Calculate the percentage change
in dynamic pressure using the equation: q = 1/2 ρV^2.
a) 20% increase
b) 32% increase
c) 44% increase
d) 56% increase
Solution:
New q / Old q = (1.2V)^2 / V^2 = 1.44
Percentage change = (1.44 - 1) × 100% = 44%
Answer: c) 44% increase
35. The fuselage length is increased by 5%. What is the percentage change in the aircraft's pitch
moment of inertia, assuming it is proportional to the square of the fuselage length?
a) 5% increase
b) 7.7% increase
c) 10.3% increase
d) 12.9% increase
Solution:
New inertia / Old inertia = (1.05 × length)^2 / length^2 = 1.1025
Percentage change = (1.1025 - 1) × 100% = 10.25%
Answer: c) 10.3% increase
Winglets are added to an aircraft, reducing the effective aspect ratio by 20%. What is the percentage
change in the induced drag factor?
a) 10.5% decrease
b) 13.6% decrease
c) 16.7% decrease
d) 19.8% decrease
Answer: c) 16.7% decrease
11. The parasite drag coefficient decreases by 10% and the induced drag coefficient increases by 5%.
What can be said about the change in lift-to-drag ratio?
a) It always increases
b) It always decreases
c) It remains the same
d) It depends on the original lift and drag coefficients
Answer: d) It depends on the original lift and drag coefficients
12. If the dihedral angle of a wing is increased from 3° to 5°, what is the percentage change in the
lateral stability derivative?
a) 33.3% increase
b) 50.0% increase
c) 66.7% increase
d) 83.3% increase
Answer: c) 66.7% increase
13. An aircraft's weight is reduced by 8% and the wing area is increased by 5%. What is the
percentage change in wing loading?
a) 8.7% decrease
b) 10.5% decrease
c) 12.4% decrease
d) 14.3% decrease
Answer: c) 12.4% decrease
14. The wing sweep is increased from 0° to 30°. What is the approximate percentage change in the
critical Mach number?
a) 10.5% increase
b) 15.5% increase
c) 20.5% increase
d) 25.5% increase
Answer: b) 15.5% increase
15. If the aspect ratio of a wing is doubled, what is the percentage change in the lift curve slope?
a) 25.0% increase
b) 33.3% increase
c) 41.7% increase
d) 50.0% increase
Answer: b) 33.3% increase
16. An aircraft's weight increases by 20% and its velocity decreases by 10%. What is the percentage
change in the lift coefficient required for level flight?
a) 32.5% increase
b) 40.3% increase
c) 48.1% increase
d) 55.9% increase
Answer: c) 48.1% increase
17. The chord of a wing is increased by 10% while maintaining the same wingspan. What is the
percentage change in the wing's wetted area?
a) 5% increase
b) 10% increase
c) 15% increase
d) 20% increase
Answer: b) 10% increase
18. The tail incidence angle is changed from 2° to -1°. What is the change in the aircraft's pitch trim?
a) 1° nose-down
b) 2° nose-down
c) 3° nose-down
d) 4° nose-down
Answer: c) 3° nose-down
19. The wingspan is increased by 25% while maintaining the same wing area. What is the percentage
change in the induced drag coefficient?
a) 24% decrease
b) 30% decrease
c) 36% decrease
d) 42% decrease
Answer: c) 36% decrease
20. If the aileron area is increased by 15%, what is the approximate percentage change in the
aircraft's roll rate?
a) 10% increase
b) 15% increase
c) 20% increase
d) 25% increase
Answer: b) 15% increase
21. The wing's quarter-chord sweep angle is increased from 20° to 30°. What is the approximate
percentage change in the wing's critical Mach number?
a) 5.7% increase
b) 7.7% increase
c) 9.7% increase
d) 11.7% increase
Answer: b) 7.7% increase
22. The center of gravity is moved forward by 5% of the mean aerodynamic chord. What is the
change in the static margin?
a) 3% increase
b) 4% increase
c) 5% increase
d) 6% increase
Answer: c) 5% increase
23. The flap deflection angle is increased from 20° to 30°. Which statement is true about the change
in maximum lift coefficient?
a) It always increases by 10%
b) It always increases by 20%
c) It always decreases
d) It depends on the airfoil and flap type
Answer: d) It depends on the airfoil and flap type
24. If the winglet height is increased by 20%, what is the approximate percentage reduction in
induced drag?
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Answer: b) 4% decrease (assuming 20% effectiveness)
25. The wing aspect ratio is increased from 7 to 9. What is the approximate percentage change in the
Oswald efficiency factor?
a) 4.7% increase
b) 5.7% increase
c) 6.7% increase
d) 7.7% increase
Answer: c) 6.7% increase (assuming typical relationship)
26. The vertical tail area is increased by 12%. What is the percentage change in the aircraft's
directional stability?
a) 8% increase
b) 10% increase
c) 12% increase
d) 14% increase
Answer: c) 12% increase (assuming linear relationship)
27. An aircraft's weight is reduced by 10% and the wing area is decreased by 5%. Calculate the
percentage change in the stall speed using the equation: Vs ∝ √(W/S).
a) 1.3% decrease
b) 2.6% decrease
c) 3.9% decrease
d) 5.2% decrease
Solution:
Vs_new / Vs_old = √[(0.9W / 0.95S) / (W/S)] = √(0.9/0.95) = 0.974
Percentage change = (0.974 - 1) × 100% = -2.6%
Answer: b) 2.6% decrease
28. Both the lift and drag coefficients increase by 5%. Calculate the new lift-to-drag ratio.
a) 5% increase
b) No change
c) 5% decrease
d) Cannot be determined without original values
Solution:
New L/D = (1.05CL) / (1.05CD) = CL / CD = Original L/D
Answer: b) No change
29. The wingspan is increased by 15% while maintaining the same lift distribution. What is the
percentage change in the wing root bending moment?
a) 15% increase
b) 23.7% increase
c) 32.3% increase
d) 41% increase
Solution:
Bending moment ∝ span^2
New moment / Old moment = (1.15 × span)^2 / span^2 = 1.3225
Percentage change = (1.3225 - 1) × 100% = 32.25%
Answer: c) 32.3% increase
30. The horizontal tail volume coefficient is increased from 0.7 to 0.8. What is the percentage change
in the aircraft's pitch damping?
a) 10% increase
b) 12.5% increase
c) 14.3% increase
d) 16.7% increase
Solution:
Percentage change = (0.8 - 0.7) / 0.7 × 100% = 14.3%
Answer: c) 14.3% increase
31. The wing span is increased by 10% and the wing area is decreased by 5%. Calculate the
percentage change in aspect ratio using the equation: AR = b^2 / S.
a) 20.5% increase
b) 23.7% increase
c) 27.3% increase
d) 31.6% increase
Solution:
New AR / Old AR = (1.1b)^2 / (0.95S) / (b^2/S) = 1.21 / 0.95 = 1.273
Percentage change = (1.273 - 1) × 100% = 27.3%
Answer: c) 27.3% increase
32. The wingspan is increased by 8%. What is the percentage change in the aircraft's roll inertia,
given that roll inertia is proportional to the square of the wingspan?
a) 8% increase
b) 12.3% increase
c) 16.6% increase
d) 20.9% increase
Solution:
New inertia / Old inertia = (1.08 × span)^2 / span^2 = 1.1664
Percentage change = (1.1664 - 1) × 100% = 16.64%
Answer: c) 16.6% increase
33. The wing twist (washout) is increased from 2° to 3°. Estimate the change in the induced drag
coefficient, assuming an elliptical lift distribution and that each degree of washout reduces induced
drag by 2%.
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Solution:
Change in washout = 3° - 2° = 1°
Induced drag reduction = 1° × 2% = 2%
Answer: a) 2% decrease
34. The aircraft's velocity is increased by 20% at the same altitude. Calculate the percentage change
in dynamic pressure using the equation: q = 1/2 ρV^2.
a) 20% increase
b) 32% increase
c) 44% increase
d) 56% increase
Solution:
New q / Old q = (1.2V)^2 / V^2 = 1.44
Percentage change = (1.44 - 1) × 100% = 44%
Answer: c) 44% increase
35. The fuselage length is increased by 5%. What is the percentage change in the aircraft's pitch
moment of inertia, assuming it is proportional to the square of the fuselage length?
a) 5% increase
b) 7.7% increase
c) 10.3% increase
d) 12.9% increase
Solution:
New inertia / Old inertia = (1.05 × length)^2 / length^2 = 1.1025
Percentage change = (1.1025 - 1) × 100% = 10.25%
Answer: c) 10.3% increase
Winglets are added to an aircraft, reducing the effective aspect ratio by 20%. What is the percentage
change in the induced drag factor?
a) 10.5% decrease
b) 13.6% decrease
c) 16.7% decrease
d) 19.8% decrease
Answer: c) 16.7% decrease
11. The parasite drag coefficient decreases by 10% and the induced drag coefficient increases by 5%.
What can be said about the change in lift-to-drag ratio?
a) It always increases
b) It always decreases
c) It remains the same
d) It depends on the original lift and drag coefficients
Answer: d) It depends on the original lift and drag coefficients
12. If the dihedral angle of a wing is increased from 3° to 5°, what is the percentage change in the
lateral stability derivative?
a) 33.3% increase
b) 50.0% increase
c) 66.7% increase
d) 83.3% increase
Answer: c) 66.7% increase
13. An aircraft's weight is reduced by 8% and the wing area is increased by 5%. What is the
percentage change in wing loading?
a) 8.7% decrease
b) 10.5% decrease
c) 12.4% decrease
d) 14.3% decrease
Answer: c) 12.4% decrease
14. The wing sweep is increased from 0° to 30°. What is the approximate percentage change in the
critical Mach number?
a) 10.5% increase
b) 15.5% increase
c) 20.5% increase
d) 25.5% increase
Answer: b) 15.5% increase
15. If the aspect ratio of a wing is doubled, what is the percentage change in the lift curve slope?
a) 25.0% increase
b) 33.3% increase
c) 41.7% increase
d) 50.0% increase
Answer: b) 33.3% increase
16. An aircraft's weight increases by 20% and its velocity decreases by 10%. What is the percentage
change in the lift coefficient required for level flight?
a) 32.5% increase
b) 40.3% increase
c) 48.1% increase
d) 55.9% increase
Answer: c) 48.1% increase
17. The chord of a wing is increased by 10% while maintaining the same wingspan. What is the
percentage change in the wing's wetted area?
a) 5% increase
b) 10% increase
c) 15% increase
d) 20% increase
Answer: b) 10% increase
18. The tail incidence angle is changed from 2° to -1°. What is the change in the aircraft's pitch trim?
a) 1° nose-down
b) 2° nose-down
c) 3° nose-down
d) 4° nose-down
Answer: c) 3° nose-down
19. The wingspan is increased by 25% while maintaining the same wing area. What is the percentage
change in the induced drag coefficient?
a) 24% decrease
b) 30% decrease
c) 36% decrease
d) 42% decrease
Answer: c) 36% decrease
20. If the aileron area is increased by 15%, what is the approximate percentage change in the
aircraft's roll rate?
a) 10% increase
b) 15% increase
c) 20% increase
d) 25% increase
Answer: b) 15% increase
21. The wing's quarter-chord sweep angle is increased from 20° to 30°. What is the approximate
percentage change in the wing's critical Mach number?
a) 5.7% increase
b) 7.7% increase
c) 9.7% increase
d) 11.7% increase
Answer: b) 7.7% increase
22. The center of gravity is moved forward by 5% of the mean aerodynamic chord. What is the
change in the static margin?
a) 3% increase
b) 4% increase
c) 5% increase
d) 6% increase
Answer: c) 5% increase
23. The flap deflection angle is increased from 20° to 30°. Which statement is true about the change
in maximum lift coefficient?
a) It always increases by 10%
b) It always increases by 20%
c) It always decreases
d) It depends on the airfoil and flap type
Answer: d) It depends on the airfoil and flap type
24. If the winglet height is increased by 20%, what is the approximate percentage reduction in
induced drag?
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Answer: b) 4% decrease (assuming 20% effectiveness)
25. The wing aspect ratio is increased from 7 to 9. What is the approximate percentage change in the
Oswald efficiency factor?
a) 4.7% increase
b) 5.7% increase
c) 6.7% increase
d) 7.7% increase
Answer: c) 6.7% increase (assuming typical relationship)
26. The vertical tail area is increased by 12%. What is the percentage change in the aircraft's
directional stability?
a) 8% increase
b) 10% increase
c) 12% increase
d) 14% increase
Answer: c) 12% increase (assuming linear relationship)
27. An aircraft's weight is reduced by 10% and the wing area is decreased by 5%. Calculate the
percentage change in the stall speed using the equation: Vs ∝ √(W/S).
a) 1.3% decrease
b) 2.6% decrease
c) 3.9% decrease
d) 5.2% decrease
Solution:
Vs_new / Vs_old = √[(0.9W / 0.95S) / (W/S)] = √(0.9/0.95) = 0.974
Percentage change = (0.974 - 1) × 100% = -2.6%
Answer: b) 2.6% decrease
28. Both the lift and drag coefficients increase by 5%. Calculate the new lift-to-drag ratio.
a) 5% increase
b) No change
c) 5% decrease
d) Cannot be determined without original values
Solution:
New L/D = (1.05CL) / (1.05CD) = CL / CD = Original L/D
Answer: b) No change
29. The wingspan is increased by 15% while maintaining the same lift distribution. What is the
percentage change in the wing root bending moment?
a) 15% increase
b) 23.7% increase
c) 32.3% increase
d) 41% increase
Solution:
Bending moment ∝ span^2
New moment / Old moment = (1.15 × span)^2 / span^2 = 1.3225
Percentage change = (1.3225 - 1) × 100% = 32.25%
Answer: c) 32.3% increase
30. The horizontal tail volume coefficient is increased from 0.7 to 0.8. What is the percentage change
in the aircraft's pitch damping?
a) 10% increase
b) 12.5% increase
c) 14.3% increase
d) 16.7% increase
Solution:
Percentage change = (0.8 - 0.7) / 0.7 × 100% = 14.3%
Answer: c) 14.3% increase
31. The wing span is increased by 10% and the wing area is decreased by 5%. Calculate the
percentage change in aspect ratio using the equation: AR = b^2 / S.
a) 20.5% increase
b) 23.7% increase
c) 27.3% increase
d) 31.6% increase
Solution:
New AR / Old AR = (1.1b)^2 / (0.95S) / (b^2/S) = 1.21 / 0.95 = 1.273
Percentage change = (1.273 - 1) × 100% = 27.3%
Answer: c) 27.3% increase
32. The wingspan is increased by 8%. What is the percentage change in the aircraft's roll inertia,
given that roll inertia is proportional to the square of the wingspan?
a) 8% increase
b) 12.3% increase
c) 16.6% increase
d) 20.9% increase
Solution:
New inertia / Old inertia = (1.08 × span)^2 / span^2 = 1.1664
Percentage change = (1.1664 - 1) × 100% = 16.64%
Answer: c) 16.6% increase
33. The wing twist (washout) is increased from 2° to 3°. Estimate the change in the induced drag
coefficient, assuming an elliptical lift distribution and that each degree of washout reduces induced
drag by 2%.
a) 2% decrease
b) 4% decrease
c) 6% decrease
d) 8% decrease
Solution:
Change in washout = 3° - 2° = 1°
Induced drag reduction = 1° × 2% = 2%
Answer: a) 2% decrease
34. The aircraft's velocity is increased by 20% at the same altitude. Calculate the percentage change
in dynamic pressure using the equation: q = 1/2 ρV^2.
a) 20% increase
b) 32% increase
c) 44% increase
d) 56% increase
Solution:
New q / Old q = (1.2V)^2 / V^2 = 1.44
Percentage change = (1.44 - 1) × 100% = 44%
Answer: c) 44% increase
35. The fuselage length is increased by 5%. What is the percentage change in the aircraft's pitch
moment of inertia, assuming it is proportional to the square of the fuselage length?
a) 5% increase
b) 7.7% increase
c) 10.3% increase
d) 12.9% increase
Solution:
New inertia / Old inertia = (1.05 × length)^2 / length^2 = 1.1025
Percentage change = (1.1025 - 1) × 100% = 10.25%
Answer: c) 10.3% increase
