A Deeper Dive into DragAircraft & Engines — DGCA CPL practice questions
Question 1 of 5
Total drag is the sum of:
All 5 questions — A Deeper Dive into Drag
Aircraft & Engines · DGCA CPL. The correct option is marked on each.
Q1. Total drag is the sum of:
- A.Form drag and skin friction
- B.Parasite drag and induced drag✓
- C.Interference drag and induced drag
- D.Profile drag and form drag
Why: Total Drag = Parasite Drag (skin friction + form + interference) + Induced Drag.
Q2. If airspeed is doubled, parasite drag will:
- A.Double
- B.Quadruple✓
- C.Halve
- D.Remain the same
Why: Parasite drag increases as the square of airspeed — double the speed, four times the parasite drag.
Q3. Vmd, the minimum drag speed, occurs where:
- A.Parasite drag is zero
- B.Induced drag equals parasite drag✓
- C.Induced drag is maximum
- D.Thrust equals weight
Why: The total drag curve bottoms out where the induced and parasite drag curves intersect; this corresponds to the AOA for L/D max.
Q4. At speeds below Vmd an aircraft is speed-unstable because:
- A.Parasite drag rises sharply as speed falls
- B.Induced drag rises sharply as speed falls✓
- C.Thrust increases as speed falls
- D.The CG moves aft
Why: On the 'back side' of the drag curve a speed loss raises induced drag, deepening the deceleration unless the pilot adds thrust — the region of reversed command.
Q5. Flying at a constant IAS, the total drag with increasing altitude will:
- A.Increase
- B.Decrease
- C.Not vary✓
- D.First decrease then increase
Why: Constant IAS means constant dynamic pressure, so drag does not vary with altitude.