Hydromechanical Fuel Control ................................2-35 Hydromechanical/Electronic Fuel Control...............2-35 FADEC Fuel Control Systems .................................2-37 FADEC for an Auxiliary Power Unit.......................2-37 FADEC Fuel Control Propulsion Engine.................2-39 Fuel System Operation .............................................2-41 Water Injection System................................................2-41 Fuel Control Maintenance............................................2-42 Engine Fuel System Components ................................2-43 Main Fuel Pumps (Engine Driven) ..........................2-43 Fuel Heater ...............................................................2-43 Fuel Filters................................................................2-44 Fuel Spray Nozzles and Fuel Manifolds ..................2-45 Simplex Fuel Nozzle ................................................2-46 Duplex Fuel Nozzle..................................................2-46 Airblast Nozzles .......................................................2-46 Flow Divider ............................................................2-46 Fuel Pressurizing and Dump Valves ........................2-47 Combustion Drain Valves ........................................2-47 Fuel Quantity Indicating Units.....................................2-48 Chapter 3 Induction and Exhaust Systems ........................3-1 Reciprocating Engine Induction Systems ......................3-1 Basic Carburetor Induction System............................3-2 Induction System Icing ...........................................3-4 Induction System Filtering .....................................3-5 Induction System Inspection and Maintenance ......3-5 Induction System Troubleshooting.........................3-5 Supercharged Induction Systems ...............................3-5 Internally Driven Superchargers.............................3-6 Turbosuperchargers ................................................3-8 Normalizer Turbocharger .....................................3-11 Ground-Boosted Turbosupercharger System .......3-11 A Typical Turbosupercharger System ..................3-13 Turbocharger Controllers and System  Descriptions ..........................................................3-15 Variable Absolute Pressure Controller (VAPC)...3-16 Sloped Controller..................................................3-16 Absolute Pressure Controller................................3-17 Turbocharger System Troubleshooting ................3-17 Turbine Engine Inlet Systems......................................3-17 Divided-Entrance Duct.............................................3-19 Variable-Geometry Duct ..........................................3-19 Compressor Inlet Screens.........................................3-20 Bellmouth Compressor Inlets...................................3-20 Turboprop and Turboshaft Compressor Inlets .........3-21 Turbofan Engine Inlet Sections................................3-21 Reciprocating Engine Exhaust Systems.......................3-22 Radial Engine Exhaust Collector Ring System........3-23 Manifold and Augmentor Exhaust Assembly ..........3-24 Reciprocating Engine Exhaust System  Maintenance Practices..............................................3-24 Exhaust System Inspection.......................................3-24 Muffler and Heat Exchanger Failures ......................3-25 Exhaust Manifold and Stack Failures.......................3-25 Internal Muffler Failures ..........................................3-25 Exhaust Systems with Turbocharger ...........................3-26 Augmentor Exhaust System .....................................3-26 Exhaust System Repairs ...........................................3-26 Turbine Engine Exhaust Nozzles .............................3-26 Convergent Exhaust Nozzle .....................................3-28 Convergent-Divergent Exhaust Nozzle....................3-28 Thrust Reversers ..........................................................3-28 Afterburning/Thrust Augmentation .............................3-29 Thrust Vectoring ..........................................................3-31 Engine Noise Suppression ...........................................3-31 Turbine Engine Emissions ...........................................3-33 Chapter 4 Engine Ignition and Electrical Systems ............4-1 Reciprocating Engine Ignition Systems.........................4-1 Magneto-Ignition System Operating Principles.............4-2 High-Tension Magneto System Theory of  Operation....................................................................4-2 Magnetic Circuit .....................................................4-2 Primary Electrical Circuit .......................................4-4 Secondary Electrical Circuit ...................................4-6 Magneto and Distributor Venting...............................4-7 Ignition Harness .........................................................4-8 Ignition Switches........................................................4-9 Single and Dual High-Tension System Magnetos ...4-10 Magneto Mounting Systems.....................................4-10 Low-Tension Magneto System.............................4-10 FADEC System Description ........................................4-12 Low-Voltage Harness...............................................4-13 Electronic Control Unit (ECU).................................4-14 PowerLink Ignition System......................................4-14 Auxiliary Ignition Units...............................................4-15 Booster Coil..............................................................4-15 Impulse Coupling .....................................................4-17 High-Tension Retard Breaker Vibrator....................4-18 Low-Tension Retard Breaker Vibrator.....................4-19 Spark Plugs ..................................................................4-20 Reciprocating Engine Ignition System  Maintenance and Inspection ........................................4-22 Magneto-Ignition Timing Devices...............................4-23 Built-In Engine Timing Reference Marks................4-23 Timing Disks ............................................................4-24 Piston Position Indicators.........................................4-24 XIII