Ex 3 (Ancillary Controls)

Question 1

What are the 3 main causes for carburetor ice?

Answer 1

1. ) Impact icing
2. ) Venturi effect leading to pressure/temp drop
3. ) Heat of vaporization by fuel

Question 2

What are the indications of carburetor icing?

Answer 2

• Engine RPM will drop

- Engine will run audibly rough

Question 3

What are the effects of applying carburetor heat?

Answer 3

• Engine RPM will drop by approx. 9%

- Mixture will be now more rich leading to roughness

Question 4

What is the rule of thumb for using carburetor heat?

Answer 4

• BEFORE ice begins to form

Question 5

Generally speaking, what are the 5 situations to use carburetor heat?

Answer 5

• During low engine RPM’s (below the green arc)
• On descents
• Visible moisture
• Every 15 mins
• During HASEL checks

Question 6

When not to use carburetor heat?

Answer 6

• Takeoff
• Taxi
• Climb
• General cruise

Question 7

Why is mixture used?

Answer 7

To burn fuel at an optimum point. Too lean and the engine RPM will be low. To rich and the enginer RPM with be low and spoil the spark plugs

Question 8

When must the mixture be maintained at full richness?

Answer 8

During:

• Takeoff
• Landing
• Climb