What are the components and requirements of an aircraft engine fuel system?

Engine fuel system components include: Fuel pump (low pressure for metering, high pressure for injection), Fuel metering unit (controls flow based on FADEC commands), Fuel/oil heat exchanger (heats fuel, cools oil), Fuel filter (removes contaminants), Fuel distribution manifolds (deliver to nozzles), and Fuel nozzles (atomize for combustion). Requirements: Precise metering over 40:1 flow range, Ice crystal protection (heated components), Contamination tolerance, Failure modes accommodating single failures, and Rapid response for power transients. Modern systems use pressure-regulating valves and servo-controlled metering for accurate flow control. Integration with FADEC enables health monitoring and degradation compensation.