16 / 20
An aeroplane in straight and level flight at 100 kt is subjected to a sudden disturbance in speed. Assuming the angle of attack remains constant initially and the load factor reaches a value of 1.96:
  • A
    the speed will have increased by 20 kt.
  • B
    the speed will have decreased by 40 kt.
  • C
    the speed will have decreased by 20 kt.
  • D
    the speed will have increased by 40 kt.

Load Factor is the ratio of the weight of an aircraft to the load imposed by lift: Load Factor = Lift / Weight
Lift is propotional to V2: L= CL × ½ rho × V2 × S

Therefore, n is proportional to V2 . An increase in "n" to 1.96 means lift has increased by a factor of 1.96. Consequently, "V" must change by a factor of √1.96 = 1.4.

The speed has increased to: 100 x 1.4 = 140 kt (= an increase of 40 kt)


Your Notes (not visible to others)



This question has appeared on the real examination, you can find the related countries below.

  • Italy
    2
  • France
    1
Keyboard Shortcut Use Keyboard Shortcuts