AEROFOIL SECTIONS – Air – DGCA Question Bank For Politics

#1. Two aircraft have the same wing shape and area if one has straight wings and the other swept wings how will the aspect ratios of the two aircraft compare?

No change.

Aspect ratio will increase as wings stveepback angle increases

Aspect ratio will decrease as wing sweepback angle increases.

Depends on the C of G position.

#2. Which wing plan forms are most susceptible to tip stall?

High aspect ratio, elliptical, Low taper ratio, straight.

High aspect ratio, pointed, high taper ratio, swept.

Low aspect ratio, elliptical, low taper ratio, straight.

Low aspect ratio, pointed, low taper ratio, swept.

#3. Which of the following are true of low aspect ratio rectangular wings?

They produce low induced drag and high profile drag.

They produce low profile drag and high induced drag.

They are difficult to construct and their roots stall before their tips.

'They are easy to construct and their tips stall before their roots.

#4. In what direction is the airflow deflected as it passes over the tips of lift generating pointed wings.

Downwards.

Forwards.

Upwards.

Aft.

#5. Which of the following statements are true of elliptical wings? 1. Almost the entire wing reaches its stalling angle simultaneously. 2. It poses structural problems making design and construction difficult. , 3. The aircraft exhibits little or no pre-stall buffet. 4. Aileron effectiveness is reduced close to the stall.

1, 2,3.

1,2,4.

2,3,4.

All of the above.

#6. What is the principal advantage of an elliptical wing plan form?

Reduced induced drag.

Reduced wing flutter.

Maximum strength : weight ratio.

Reduced profile drag.

#7. Where on a lift generating pointed wing is the greatest downwash?

At the tips.

Close to the roots

At the % span point.

At the leading edge.

#8. Where on a CI/CL : semi-span distance chart do the curves for all non-elliptical wings coincide?

Approximately at the 1.1, 0.55 point.

Approximately at the 0,0 point.

Approximately at the 0.55,1.1 point.

Approximately at the 1.1 point.

#9. Which of the following statements best describes the effect of reducing aspect ratio?

The slope of the CL:a curve decreases and stalling angle increases.

The slope of the CL:a curve decreases and stalling angle decreases

The slope of the CL:a curve increase and stalling angle increases.

The slope of the CL:a curve increase and stalling angle decreases.

#10. Which of the following is the most accurate definition of dihedral angle?

The horizontal angle between the 25% chord line and the lateral axis.

The vertical angle between the longitudinal axis and the wing spar.

The vertical angle between the wing plane and tlie lateral axis.

The angle between the chord line and the longitudinal axis.

#11. What are the angle of incidence and incidence respectively?

They are the same thing.

The angle between the chord line and the longitudinal axis and the angle of attack respectively.

The angle of attack and the angle between the chord line and the normal axis.

The angle between the chord line and the longitudinal axis, and between the chord line and the free stream airflow respectively.

#12. What is the relationship between the mean camber line and the chord line of a symmetrical aerofoil?

They are the same thing.

They are closest at the mid chord point.

They have nothing in common.

They never meet.

#13. What is the principal cause of deep stall?

Tip stalling of swept back wings.

Tip stalling of straight wings.

Tip stalling of tapered wings.

High tailplanes.

#14. How is the aspect ratio of a wing of complex plan form calculated?

Span / chord.

Chord / span.

By computer.

Span squared / wing area.

#15. What is the angle of attack?

The angle between the chord line and the longitudinal axis.

The angle between the chord line and the relative airflow.

The angle between the chord line and the free stream airflow.

The angle between the total reaction and the chord line.

#16. How does a supercritical aerofoil compare with a convention design?

Thinner, more cambered and convex under rear surface.

Thicker, less cambered and concave under rear surface.

Thinner, less cambered and concave under rear surface.

Thicker, more cambered and convex under rear surface.

#17. What effect will increasing aspect ratio have on drag at low and high speeds?

Decrease profile at low speeds and increase induced at high speeds.

Decrease induced at low speeds, no effect at high speeds.

Increases induced at low speed and decrease induced at high speeds.

Decrease induced and increase profile at all speeds.

#18. What effect will increasing aspect ratio have on stalling angle?

Decrease.

Increase.

None.

Increase or decrease depending on weight.

#19. What effect will increasing aspect ratio have on stalling speed?

Increase.

Decrease.

None.

Increase or decrease depending on weight.

#20. Why do aircraft with swept back wings pitch up in the stall?

C of P moves aft.

C of P moves outward and forward.

C of P moves inward and forward.

They do not pitch up.

#21. How does the CL:a curve of a swept wing compare with that of a straight wing?

Steeper and lower maximum.

Shallower and higher maximum.

Steeper and higher maximum.

Shallower and lower maximum.

#22. How does the stalling angle of a swept wing compare with that of a straight wing of equal section?

Lower.

Higher.

The same.

Higher or lower depending on weight.

#23. How would the stalling speed of a swept wing compare with that of a straight wing of equal section?

Higher.

Lower.

The same.

Higher or lower depending on altitude.

#24. What is the mean aerodynamic chord?

The shortest.

The longest.

The flattest.

The average.

#25. Increasing sweep back angle .........?

Decrease induced drag.

Increases profile drag.

Increases MCRIT.

Increases wave drag.

#26. Increasing sweep back angle.......... ?

Increases induced drag.

Increases profile drag.

Increases wave drag.

Increases flutter.

#27. Increasing sweep back angle........?

Increases gust response.

Decrease gust response.

Increases flutter.

Increases divergence.

#28. Aerodynamic washout is.........?

Changing wing section from root to tip.

Increasing T:C ratio from root to tip.

Down wash.

Oscillating pitching motion.

#29. Divergence is caused by..........?

C of P ahead of torsional axis, thin wings and excessive airspeeds.

C of P aft of torsional axis, thin wings and excessive thrust.

C of G aft of C of P, thick wings and excessive weight.

C of P aft of C of G, thin wings and excessive airspeed.

#30. Angle of incidence is.........?

Between camber line and longitudinal axis.

Between chord line and longitudinal axis.

Between chord line and lateral axis.

Between camber line and lateral axis.

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