PLT191: Carburetors
What code PLT191 covers, why the FAA tests it, and how to study Carburetors before your checkride.
Recall carburetors - types / components / operating principles / characteristics
What this means for your checkride
A float-type carburetor meters fuel into the induction airflow: air through a venturi drops in pressure and draws fuel from the float chamber, and the mixture control adjusts the fuel-to-air ratio. Because the venturi cools, carburetors are prone to icing even in warm weather.
The carburetor's operation underlies mixture control and carb icing, so the FAA tests how it meters fuel and why it ices.
Pilots think leaning is only for high altitude. As you climb, the air thins while the carburetor keeps metering fuel, so the mixture richens and must be leaned for smooth, efficient running.
Where to study it
A code on your test report is an area of deficiency. An authorized instructor must review it with you and endorse that review before you take the practical test, and the examiner may revisit it during the oral. Study it until you can explain it out loud, not just recognize the answer.