1. 9.03 Carburetor, Mixture, and Icing References: FTGU pages 61-68
Aero Engines
9.03 Carburetor, Mixture, and Icing
References: FTGU pages 61-68

2. Review
This type of fuel system relies on fuel pump to keep fuel flowing to the engine.
What is vapour lock?
What are the 4 functions of oil?
Answers:
Forced-feed / fuel pump fuel system
High atmospheric temperature causes gas to vaporize and block the flow of liquid fuel in the line
Cooling, sealing, lubrication, flushing

3. 9.03 Carburetor, Mixture, and Icing
MTPs:
Functions of the Carburetor
Parts of a Carburetor
Mixture
Carburetor Ice

4. Functions of the Carburetor
Carburetor is the heart of an engine. The two key functions of the carburetor are:
(1) Vaporize the Fuel
(2) Mix Fuel and Air

5. The Carburetor

6. Parts of the Carburetor

7. Carburetor Mixture Ratios
Fuel-Air mixture
Running mixture
1:8
Best power mixture
1:14
Chemically correct mixture
1:15
Lowest fuel consumption mixture
1:18
Leanest running mixture
1:20

8. Mixture Controls

9. Mixture Control Fuel-Air mixture Too rich a mixture may lead to:
Rich: lots of fuel
Lean: little fuel
Too rich a mixture may lead to:
Unburned fuel in exhaust (wasteful)
Fouled spark plugs
Rough running engine
Loss of power
Engine failure
Too lean a mixture may lead to:
Overheating
Back-firing
Detonation

10. Carburetor Ice
Ice can form in the carburetor and will restrict air flow to the engine, resulting in:
Loss of Power
Rough Running Engine
Total Engine Failure
Ice can READILY form in the carburetor in CLEAR AIR with ambient air temperatures from -5 to +30 degrees Celsius, depending on the humidity of the air

11. Carburetor Ice

12. Icing – Dangerous Conditions
Serious Icing - cruise or climb power
Moderate Icing - cruise power or serious icing - glide power
Serious Icing - glide power
Light Icing – cruise or glide power

13. Dangerous Conditions

14. Carburetor Heat
Use of Carb-heat and its Effects on Mixture

15. Confirmation What are the 2 key functions of the carburetor?
What is the best power mixture ratio?
Under what conditions can carburetor icing occur?
Answers:
Vaporize the fuel, mix fuel and air
1:14
Clear air, ambient temperatures -5 to +30 degrees celsius

16. Full rich…