PoF Chapter 8 High Lift Devices

The main purpose of high lift devices is to:

• reduce endurance

• increase range

• reduce the take-off and landing distances

• reduce lift

Plain flap is used mainly on:

• low wing aircraft and where short take-off and landing is not required

• high speed aircraft where short take-off and landing is necessary

• high speed aircraft where short take-off and landing is not necessary

• low speed aircraft and where short take-off and landing is not required

The purpose of the slot is to:

• direct lower pressure air from the upper surface over the flap and re-energize the boundary layer

• direct higher pressure air from the lower surface over the flap and re-energize the boundary layer

• direct higher pressure air from the upper surface over the flap and re-energize the boundary layer

• reduce drag to increase take-off and landing distances

The Fowler flap:

• moves down then rearwards, initially giving an increase in wing area and then an increase in camber

• moves rearwards then down, initially giving a decrease in wing area and then a decrease in camber

• moves rearwards and then down, initially giving an increase in wing area and then an increase in camber

• moves down then rearwards, initially giving an increase in wing area then a decrease in camber

Which flap gives the greatest increase in lift and the least drag?

• Fowler flap

• Plain flap

• Split flap

• Slotted flap

When the flap is lowered:

• the Centre of Pressure will move forward giving a nose-up pitching moment

• the Centre of Pressure will move rearwards giving a nose-down pitching moment

• the Centre of Pressure will move rearwards giving a nose-up pitching moment

• the Centre of Pressure will move forward giving a nose-down pitching moment

The main effect of the leading edge flap is to:

• delay separation and so decrease the stalling angle

• advance separation and so increase the stalling angle

• advance separation and so decrease the stalling angle

• delay separation and so increase the stalling angle

When slats are deployed:

• the stalling angle is reduced

• the boundary layer is re-energized

• the C_LMAX is reduced

• the C_LMAX is unchanged

Which of the following statement is correct regarding the use of flap?

• the trailing edge flap should be deployed before the leading edge flap is lowered

• the leading edge device should be retracted before the trailing edge flap is raised

• the leading edge device should be deployed before the trailing edge flap is lowered

• the leading edge and trailing edge flaps are operated at the same time

Which trailing edge flap gives the highest drag?

• slotted flap

• Fowler flap

• plain flap

• split flap