Constant Speed Propeller BOLDMETHOD

Question 1

What does the blue knob next to the throttle control?

Answer 1

The propeller control — it selects propeller/engine RPM by adjusting blade pitch.

Question 2

What does a constant‑speed propeller allow you to do?

Answer 2

Select the RPM you want for any phase of flight (takeoff, climb, cruise, landing).

Question 3

How does a constant‑speed propeller change thrust?

Answer 3

• By varying blade pitch
• Higher pitch = more thrust but lower RPM
• Lower pitch = less thrust but higher RPM

Question 4

Why is it called a “constant‑speed” propeller?

Answer 4

Because the governor automatically maintains the selected RPM by adjusting blade pitch.

Question 5

What RPM setting do you use for takeoff?

Answer 5

High RPM (low pitch).

Question 6

What RPM setting do you use for cruise?

Answer 6

Lower RPM (higher pitch).

Question 7

What happens when blade angle increases?

Answer 7

• More thrust
• More torque required
• Engine RPM decreases

Question 8

What happens when blade angle decreases?

Answer 8

• Less torque required
• Engine RPM increases

Question 9

What is the low‑pitch/high‑RPM setting used for?

Answer 9

Takeoff, landing, and go‑around.

Question 10

What is the high‑pitch/low‑RPM setting used for?

Answer 10

Cruise efficiency and reduced engine wear.

Question 11

What fluid changes the propeller blade angle?

Answer 11

Engine oil.

Question 12

Why is engine oil used for prop control?

Answer 12

It provides hydraulic pressure to move the hub piston and change blade pitch.

Question 13

What helps return the prop to low pitch/high RPM?

Answer 13

• A spring behind the hub piston
• Natural aerodynamic twisting forces

Question 14

Why are blade travel stops installed?

Answer 14

To prevent the blade from going fully flat or fully feathered in a single‑engine airplane.

Question 15

What does the governor do?

Answer 15

Moves oil into/out of the prop hub to maintain selected RPM.

Question 16

What connects the cockpit prop lever to the governor?

Answer 16

The governor control lever.

Question 17

What does the threaded shaft do?

Answer 17

Adjusts speeder spring tension based on prop lever position.

Question 18

What does the speeder spring do?

Answer 18

Pushes on the flyweights; its tension sets the desired RPM.

Question 19

What do the flyweights sense?

Answer 19

Engine RPM via centrifugal force.

Question 20

What happens to flyweights when RPM increases?

Answer 20

They fly outward and lift the pilot valve.

Question 21

What happens to flyweights when RPM decreases?

Answer 21

They fall inward under speeder spring pressure.

Question 22

What does the pilot valve do?

Answer 22

Ports oil into or out of the prop hub to change blade pitch.

Question 23

What does the governor gear pump do?

Answer 23

Boosts oil pressure for fast, precise pitch changes.

Question 24

What is an underspeed condition?

Answer 24

Engine RPM drops below selected value (e.g., pitching up).

Question 25

How does the governor correct **underspeed**?

Answer 25

* Flyweights fall inward * Pilot valve lowers * Oil flows OUT * Blade pitch decreases * RPM increases

Question 26

What is an **overspeed condition**?

Answer 26

Engine RPM rises above selected value (e.g., pitching down).

Question 27

How does the governor correct **overspeed**?

Answer 27

* Flyweights move outward * Pilot valve rises * Oil flows IN * Blade pitch increases * RPM decreases

Question 28

What prop setting is used for **takeoff and landing**?

Answer 28

Full forward (low pitch/high RPM).

Question 29

Why use **full RPM** for landing?

Answer 29

Instant power available for go‑around.

Question 30

What happens when you pull the **prop lever back** in cruise?

Answer 30

Blade pitch increases, torque demand increases, engine RPM decreases.

Question 31

Why is **high pitch** more efficient in cruise?

Answer 31

Slower RPM, less fuel burn, less engine wear.

Question 32

What is the **bike‑gear analogy** for prop pitch?

Answer 32

* High pitch = high gear (slow RPM, efficient) * Low pitch = low gear (fast RPM, high power)

Question 33

What happens if you **lose engine oil** in a single‑engine constant‑speed prop?

Answer 33

Prop moves to low pitch/high RPM (“fails forward”).

Question 34

Why does the prop fail to **low pitch/high RPM**?

Answer 34

Spring pressure + aerodynamic twisting moment push blades to low pitch.

Question 35

What is the bigger problem if you **lose all engine oil**?

Answer 35

The engine will likely fail soon after.

Question 36

What are the **three main benefits** of a constant‑speed propeller?

Answer 36

* Select optimal RPM for each phase of flight * Better performance * Better efficiency

Question 37

What makes you look like a **genius** to passengers?

Answer 37

Having an extra engine control — the prop lever.