PPL PPL Aircraft Systems and Powerplant 1 — Questions and Answers
Question 1: What type of fuel is used in most piston-engine training aircraft?
- 100LL Avgas (Correct answer)
- Jet-A
- Mogas
- 100 Avgas
Correct answer: 100LL Avgas
Most piston-engine training aircraft use 100LL (low lead) aviation gasoline, identifiable by its blue color.
Question 2: What does the carburetor heat control do in a piston aircraft?
- Heats the fuel before combustion
- Routes warm air through the carburetor to prevent or melt ice (Correct answer)
- Increases engine power during climb
- Cools the engine during descent
Correct answer: Routes warm air through the carburetor to prevent or melt ice
Carburetor heat routes warm air into the carburetor venturi to melt or prevent ice formation that would otherwise block fuel-air flow.
Question 3: What is the primary purpose of the magneto system in a piston engine?
- To power the aircraft's avionics
- To provide an independent ignition source not relying on the aircraft battery (Correct answer)
- To regulate fuel flow to the carburetor
- To cool the engine cylinders
Correct answer: To provide an independent ignition source not relying on the aircraft battery
Magnetos are self-contained ignition systems that generate their own electricity, providing reliable ignition independent of the battery.
Question 4: In a fuel-injected engine, what replaces the carburetor?
- A turbocharger
- A fuel control unit and injectors delivering fuel directly to each cylinder (Correct answer)
- A primer system
- A throttle body and venturi
Correct answer: A fuel control unit and injectors delivering fuel directly to each cylinder
Fuel-injected engines use a fuel control unit and individual injectors to deliver metered fuel directly to each cylinder, eliminating the carburetor.
Question 5: What does normal oil pressure indicate in a piston aircraft engine?
- Engine temperature is within limits
- Oil is circulating through the engine to lubricate and cool internal parts (Correct answer)
- Fuel pressure is adequate
- Manifold pressure is correct
Correct answer: Oil is circulating through the engine to lubricate and cool internal parts
Oil pressure confirms the oil pump is functioning and lubricant is being circulated throughout the engine to reduce friction and carry heat away.
Question 6: What is the function of the primer in a piston aircraft?
- To enrich the fuel mixture during cruise
- To inject fuel directly into the cylinders to aid cold engine starting (Correct answer)
- To lubricate the engine before startup
- To pressurize the fuel system
Correct answer: To inject fuel directly into the cylinders to aid cold engine starting
The primer injects raw fuel into the intake manifold or cylinders to help the engine fire when cold by providing an initial rich mixture.
PPL PPL Aircraft Systems and Powerplant 1
What type of fuel is used in most piston-engine training aircraft?