POF Q12 - Stalling Part 2

Question 1

What factors affect stalling speed?
(Pick all correct answers)

a.Mass

b.Flap Configuration

c.Wing sweep

d.CG position

e.Landing Gear

Answer 1

a.Mass
b.Flap Configuration
c.Wing sweep
d.CG position
e.Landing Gear

Question 2

An aircraft has a clean stall speed of 66kts. The clean CLMAX is 1.15. If CLMAX increases by 32% when flaps are extended, what would be the new stall speed when the flaps are extended?

Please give your answer in knots with NO UNITS to the nearest whole number

Answer 2

57

VSnew = 75 x √(1.15 / 1.52)

Question 3

The stall speed of a light aircraft is 52kts at its maximum take-off mass of 1820kg with a take-off flap configuration. The light aircraft at maximum take-off weight takes off with full tanks of maximum fuel of 28USG. If the aircraft takes off with quarter tanks, what would the new stall speed be in the same configuration?
(1 USG = 3.2kg)

Please give your answer in knots with NO UNITS to the nearest knot

Answer 3

51

VSnew = 52 x √ (1753 / 1820)

Question 4

An aircraft pulls out of a steep dive at a load factor of 2.8. The straight and level stall speed is 68kts. At what speed would the aircraft stall when pulling out of the dive?

Please give your answer in knots with NO UNITS

Answer 4

114

VSnew = 68 x √ (2.8 /1)

Question 5

An aircraft that takes off with 1 stage of flaps and landing gear extended has a CLMAX of 0.73 and a take-off stall speed of 57kts. If when the aircraft cleans up and retracts the undercarriage the stall speed increases to 72kts, by how much has the CLMAX changed?

Please give numbers only to 2 decimal places.

Answer 5

0.27

CLMAXnew = 0.73 x (57 / 72)2
0.73-0.46 = 0.27

Question 6

A DA42 has a MTOM of 1999kg. When an instructor and student are in the aircraft it has a TOM of 1350kg. After 1 hour of flight, the aircraft weighs 1310kg and has a stalling speed of 75kts. If they had decided before the flight to take 2 more students with them weighing 165lbs and 180lbs respectively. What would the new stalling speed be after 1 hour flight time?

Please give your answer in knots with NO UNITS

Answer 6

79

Question 7

During a turn, an aircraft has a load factor of 1.41 and a stall speed of 81kts. What would the stall speed of the aircraft be in straight and level flight?

Please give your answer in knots with NO UNITS

Answer 7

68

VSnew = 81 x √ (1 /1.41)
VSnew = 68kts