4 Quiz DRAG

As airspeed decreases in level flight below that speed for maximum lift/drag ratio, total drag of an aeroplane:

• decreases because of lower parasite drag.

• increases because of increased parasite drag.

• increases because of increased induced drag.

• decreases because of lower induced drag.

That portion of the aircraft's total drag created by the production of lift is called:

• induced drag, and is greatly affected by changes in airspeed.

• induced drag, and is not affected by changes in airspeed.

• parasite drag, and is greatly affected by changes in airspeed.

• parasite drag, which is inversely proportional to the square of the airspeed

The best L/D ratio of an aircraft occurs when parasite drag is:

• a minimum.

• less than induced drag.

• greater than induced drag.

• equal to induced drag

An aircraft has a L/D ratio of 15:1 at 50 kts in calm air. What would the L/D ratio be with a direct headwind of 25 kts?

• 30:1

• 15:1

• 25:1

• 7.5:1

If the Indicated Air Speed of an aircraft is decreased from 100 kts to 50 kts, induced drag will be:

• four times greater.

• half as much.

• two times greater.

• one quarter as much.

Which statement is true regarding aeroplane flight at L/Dmax?

• Any angle of attack other than that for L/Dmax increases parasite drag.

• Any angle of attack other than that for L/Dmax increases the lift/drag ratio.

• Any angle of attack other than that for L/Dmax increases total drag for a given aeroplane's lift

• Any angle of attack other than that for L/Dmax increases the lift and reduces the drag.

A wing with a very high aspect ratio (in comparison with a low aspect ratio wing) will have:

• poor control qualities at low airspeeds.

• increased drag at high angles of attack.

• a low stall speed.

• reduced bending moment on its attachment points.

Which of these statements about induced drag are correct or incorrect? I. An elliptical spanwise lift distribution generates more induced drag than a rectangular lift distribution. II. Induced drag decreases with decreasing aspect ratio.

• I is correct, II is incorrect.

• I is incorrect, II is incorrect.

• I is incorrect, II is correct.

• I is correct, II is correct.

Flying at 400Kts IAS at sea level, the value of drag is 780N. What would be the value of drag at 6000ft, if the IAS is maintained, and all other factors remain constant?

• 780N

• 900N

• 656N

• 714N

Which of these variables are required to calculate drag from the drag formula?

• Total pressure and wing area only.

• Angle of attack, aspect ratio and dynamic pressure.

• Dynamic pressure, drag coefficient and wing area.

• Frontal wing area, density and wing loading.