Drag

Question 1

Induced drag is caused by air at the bottom of the wing flowing?

Answer 1

Outwards

Question 2

Induced drag is caused by air at the top of the wing flowing?

Answer 2

Inwards

Question 3

Why does the wing tip vortices result in added drag(induced drag)?

Answer 3

Because the net direction of lift is altered to act rearward in the direction of drag.

Question 4

Induced drag, relevant to airspeed, is?

Answer 4

inversely proportional to the square of the indicated airspeed

Question 5

profile drag, relevant to airspeed, is?

Answer 5

proportional to the square of the indicated airspeed

Question 6

Minimum drag can be found where?

Answer 6

Induced drag = Profile drag

Question 7

Relevant to minimum drag airspeeds, Compared to a lighter aeroplane, a heavier aeroplane will have a ?

Answer 7

higher Vmd airspeed

Question 8

Relevant to Vmd speed.

Compared to the clean configuration , an aeroplane with a dirty configuration will have a lower?

Answer 8

Vmd airspeed

Question 9

Does total drag vary with altitude?

Answer 9

No, since aeroplanes are normally operated according to IAS, drag remains the same.

Question 10

The drag formula =

Answer 10

Cd 1/2p v^2 S

Question 11

Which provides better efficiency, an high lift/drag ratio or a low lift/drag ratio?

Answer 11

An high lift/drag ratio

Question 12

The angle of attack for greatest economy is?

Answer 12

4 degrees

Question 13

The airflow is altered when in ground effect because?

Answer 13

The upwash and downwash is substantially altered

Question 14

Ground effect can be experienced within what distance above the runway?

Answer 14

Within one wingspan length.

Question 15

Ground effect increases?

Answer 15

The coefficient of lift at a given angle of attack

Question 16

Ground effect reduces the?

Answer 16

minimum speed of an aeroplane

Question 17

Due to ground effect, the aeroplane will stall - ?

Answer 17

at a lower angle of attack

Question 18

relevant to ground effect, the float sensation is caused by?

Answer 18

the increase in effective angle of attack

Question 19

relevant to ground effect, the increased float distance is caused by?

Answer 19

A reduction in induced drag

Question 20

The two types of drag -

And each sub-category

Answer 20

Parasite and induced drag

For parasite drag: Form drag, interference drag and skin friciton.

Form drag and skin friction fall under profile drag

Question 21

Parasite drag is proportional to -

Induced drag -

Answer 21

The square of IAS

Inversely proportional to the square of IAS

Question 22

the speed at which total drag is a minimum (VMD) occurs when the -

Answer 22

Induced drag and parasite drag is equal

Question 23

The effect of altitude on parasite drag -

Answer 23

Parasite drag is proportional to the IAS. Unless IAS is higher, parasite drag will not be higher. Unless the IAS is not kept constant with altitude, parasite drag will not increase

Question 24

The effect of altitude on total drag -

Answer 24

Again, drag is proportional to IAS. With a constant IAS total drag will be unchanged with altitude

Question 25

Thrust required =

Power required =

Answer 25

Drag

Drag x TAS

Question 26

Vmp and Vmd is (IAS or TAS)

Between Vmp and Vmd, which is higher?

Answer 26

IAS.

Vmd

Question 27

Effect of weight on the glide distance -

Answer 27

Weight does not change the glide distance, but will change the endurance. Glide distance is dependent on L/D ratio.

If aircraft mass is increased, the result weight component will be balanced by drag.