12 Descent

Question 1

During a Descent Schedule what happens to the Change Over Altitude if:

• Mac No is increased
• CAS is increased

Answer 1

• Mac No Increases: Ch.Over Altitude Increases

- CAS Increases: Ch.Over Altitude Decreases

Question 2

What is the equation for the Angle of Descent?

Answer 2

Sin (gamma) = (D - T) / W

Question 3

What is the speed for the minimum Angle of Descent?

Answer 3

• Vmd
• Since Sin(gamma) = (D - T) / W
• To get the minimum angle of descent, drag must be kept to a minimum

Question 4

What is the speed for the Maximum Angle of Descent?

Answer 4

• As fast as possible
• Since Sin(gamma) = (D - T) / W
• Therefore want to maximise Excess Drag which is achieved at fast speeds

Question 5

What is the speed for the Minimum Rate of Descent?

Answer 5

• A speed which is faster than Vmp but slower than Vmd

- Where the Excess Power is minimum

Question 6

What is the speed for Maximum Rate of Descent?

Answer 6

• At or below Mmo or Vmo

- Where Excess Power is greatest

Question 7

When is an AC glide angle smallest?

Answer 7

• CL / CD max
• 4 degrees AOA
• Vmd

Question 8

What effect does increasing Mass have on the Glide Range and Glide Endurance?

Answer 8

• Glide Range is unaffected
• Glide Endurance is reduced as the AC will still fly at Vmd but Vmd will be faster and so it will reach the ground quicker

Question 9

What speed will an AC Glide at in order to maximise Endurance?

Answer 9

Vmp

Question 10

What effect will a Headwind have on Glide Range and Glide Endurance?

Answer 10

• Glide Range is reduced

- Glide Endurance is not affected

Question 11

When descending above the change over altitude what happens to:

• Pitch Angle
• Flight Path Angle
• AOA
• CL

Answer 11

• Pitch Angle decreases
• Flight Path Angle increases
• AOA decreases
• CL decreases