For an aircraft to operate reliably in every phase of flight and in all expected environments, its fuel system must store and maintain a sufficient quantity of fuel and deliver it to the powerplant without interruption or contamination. The entire fuel system can be divided into three functional areas: storage, delivery, and distribution.
The earliest systems were very simple, including a tank, fuel lines, a selector valve, and a carburetor. Over time, powerplant technology advanced, and with increased power came more complexity and more specific demands for distributing fuel. Fuel systems are designed to efficiently meet the design requirements of an aircraft powerplant with particular considerations for safety. Aviation maintenance technicians must be thoroughly familiar with the design, operation, and maintenance of the aircraft fuel system before inspecting or performing maintenance.
Aircraft fuel systems have two basic sections: airframe and powerplant. The airframe section consists of all the parts associated with storage and delivery, including the components from the fuel tanks to the engine-driven pump. The powerplant section consists of the distribution parts, beginning after the engine-driven fuel pump and concluding at the point where air and fuel are mixed for combustion.
The following posts in this series introduce the fundamental requirements, mechanical designs, and maintenance procedures for both reciprocating and turbine engine fuel metering systems.
Chapter Learning Path
1. Fuel System Requirements
Learn the mandatory safety and performance standards for aircraft fuel storage and delivery.
View Topic →2. Basic Fuel System
Study the fundamental layout of gravity-feed and pressure-feed fuel system configurations.
View Topic →3. Fuel Metering Devices
Understand the evolution and function of metering units in reciprocating engines.
View Topic →4. Carburetion Principles
Explore the physics of Venturi effect, pressure differentials, and air-fuel ratios.
View Topic →5. Carburetor Systems
Study the auxiliary systems including idling, acceleration, and power enrichment circuits.
View Topic →6. Carburetor Types and Icing
Understand the various carburetor designs and the critical hazards of fuel evaporation ice.
View Topic →7. Float Type Carburetors
Explore the mechanical operation of float mechanisms and needle valves in fuel regulation.
View Topic →8. Pressure Injection Carburetors
Learn about pressurized fuel metering and the role of Automatic Mixture Control (AMC).
View Topic →9. Stromberg PS Carburetor
Study the specific operation and maintenance of the Stromberg pressure-type carburetor.
View Topic →10. Fuel Injection Systems
Understand the benefits and mechanics of direct fuel injection in modern aircraft engines.
View Topic →11. Carburetor Maintenance
Learn the procedures for cleaning, adjusting, and troubleshooting carburetor installations.
View Topic →12. System Inspection & Maintenance
Explore the best practices for inspecting fuel lines, filters, and airframe delivery components.
View Topic →13. Turbine Fuel Requirements
Understand the high-volume and high-pressure demands of modern gas turbine fuel systems.
View Topic →14. Fuel Control Maintenance
Study the calibration and servicing of complex hydro-mechanical and electronic fuel controls.
View Topic →15. Engine Fuel Components
Explore the hardware including pumps, heaters, valves, and nozzles used in fuel distribution.
View Topic →