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Aviation Maintenance Technician Handbook Powerplant Volume 1

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Aviation Maintenance Technician Handbook–Powerplant (FAA-H-8083-32A) Volume 1
Federal Aviation Administration
286 pages

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Open: Aviation Maintenance Technician Handbook–Powerplant (FAA-H-8083-32A)

The Aviation Maintenance Technician Handbook–Powerplant (FAA-H-8083-32A) is one of a series of three handbooks for persons preparing for certification as a powerplant mechanic. It is intended that this handbook provide the basic information on principles, fundamentals, and technical procedures in the subject matter areas relating to the powerplant rating. It is designed to aid students enrolled in a formal course of instruction, as well as the individual who is studying on his or her own. Since the knowledge requirements for the airframe and powerplant ratings closely parallel each other in some subject areas, the chapters which discuss fire protection systems and electrical systems contain some material which is also duplicated in the Aviation Maintenance Technician Handbook–Airframe (FAA-H-8083-31A).

This handbook contains an explanation of the units that make up each of the systems that bring fuel, air, and ignition together in an aircraft engine for combustion. It also contains information on engine construction features, lubrication systems, exhaust systems, cooling systems, cylinder removal and replacement, compression checks, and valve adjustments. Because there are so many different types of aircraft in use today, it is reasonable to expect that differences exist in airframe components and systems. To avoid undue repetition, the practice of using representative systems and units is carried out throughout the handbook. Subject matter treatment is from a generalized point of view and should be supplemented by reference to manufacturer's manuals or other textbooks if more detail is desired. This handbook is not intended to replace, substitute for, or supersede official regulations or the manufacturer’s instructions. Occasionally the word “must” or similar language is used where the desired action is deemed critical. The use of such language is not intended to add to, interpret, or relieve a duty imposed by Title 14 of the Code of Federal Regulations (14 CFR).

TOC

Volume Contents. ...................................................V
Preface..................................................................VII
Acknowledgments. ................................................IX
Table of Contents. .................................................XI
Chapter 1Aircraft Engines. ...................................................1-1
General Requirements. ....................................................1-1
Power and Weight. ......................................................1-2
Fuel Economy. ............................................................1-3
Durability and Reliability. ...........................................1-3
Operating Flexibility. ..................................................1-3
Compactness. ...............................................................1-3
Powerplant Selection. ..................................................1-3
Types of Engines. ............................................................1-4
Inline Engines. .............................................................1-4
Opposed or O-Type Engines. ......................................1-4
V-Type Engines. ..........................................................1-5
Radial Engines. ............................................................1-5
Reciprocating Engines. ...................................................1-5
Design and Construction. ............................................1-5
Crankcase Sections. .....................................................1-5
Accessory Section. ......................................................1-7
Accessory Gear Trains. ...............................................1-7
Crankshafts. ....................................................................1-8
Crankshaft Balance...................................................1-10
Dynamic Dampers. ....................................................1-10
Connecting Rods. ..........................................................1-10
Master-and-Articulated Rod Assembly. ....................1-11
Knuckle Pins. ............................................................1-12
Plain-Type Connecting Rods....................................1-12
Fork-and-Blade Rod Assembly. ................................1-12
Pistons. ..........................................................................1-12
Piston Construction. ..................................................1-12
Piston Pin. ..................................................................1-13
Piston Rings. .................................................................1-14
Piston Ring Construction. .........................................1-14
Compression Ring. ....................................................1-14
Oil Control Rings. .....................................................1-14
Oil Scraper Ring. .......................................................1-14
Cylinders. ......................................................................1-14
Cylinder Heads. .........................................................1-15
Cylinder Barrels. .......................................................1-16
Cylinder Numbering. .................................................1-16
Firing Order. .................................................................1-16
Single-Row Radial Engines......................................1-16
Double-Row Radial Engines. ....................................1-17
Valves. ..........................................................................1-17
Valve Construction. ...................................................1-17
Valve Operating Mechanism. .......................................1-18
Cam Rings. ................................................................1-19
Camshaft. ...................................................................1-20
Tappet Assembly. ......................................................1-20
Solid Lifters/Tappets. ................................................1-21
Hydraulic Valve Tappets/Lifters. ..............................1-21
Push Rod. ..................................................................1-21
Rocker Arms.............................................................1-22
Valve Springs. ...........................................................1-22
Bearings. .......................................................................1-22
Plain Bearings. ..........................................................1-23
Ball Bearings. ............................................................1-23
Roller Bearings. .........................................................1-23
Propeller Reduction Gearing. ........................................1-24
Propeller Shafts. ............................................................1-24
Reciprocating Engine Operating Principles. .................1-24
Operating Cycles. ..........................................................1-26
Four-Stroke Cycle. ....................................................1-26
Intake Stroke. .........................................................1-27
Compression Stroke. ..............................................1-27
Power Stroke. .........................................................1-27
Exhaust Stroke. ......................................................1-28
Two-Stroke Cycle.....................................................1-28
Rotary Cycle. .............................................................1-28
Diesel Cycle. .............................................................1-28
Reciprocating Engine Power and Efficiencies. .............1-28
Work. .........................................................................1-28
Horsepower. ..............................................................1-28
Piston Displacement. .................................................1-29
Area of a Circle. ........................................................1-29
Example. ................................................................1-29
Compression Ratio. ...................................................1-29
Indicated Horsepower...............................................1-31
Example. ................................................................1-32
Brake Horsepower. ....................................................1-32
Example. ................................................................1-33
Friction Horsepower. .................................................1-33
Friction and Brake Mean Effective Pressures. ..........1-33
Thrust Horsepower. ...................................................1-35
Efficiencies. ..................................................................1-35
Thermal Efficiency. ...................................................1-35
Example. ................................................................1-35
Mechanical Efficiency. ..............................................1-36
Volumetric Efficiency. ..............................................1-36
Propulsive Efficiency. ...............................................1-37
Gas Turbine Engines . ...................................................1-37
Types and Construction. ............................................1-37
Air Entrance. .................................................................1-38
Accessory Section. ........................................................1-38
Compressor Section. .....................................................1-39
Compressor Types. ....................................................1-40
Centrifugal-Flow Compressors. .............................1-40
Axial-Flow Compressor. ........................................1-41
Diffuser. ........................................................................1-44
Combustion Section. .....................................................1-44
Turbine Section. ........................................................1-47
Exhaust Section. ........................................................1-52
Gas Turbine Engine Bearings and Seals. ......................1-53
Turboprop Engines. .......................................................1-56
Turboshaft Engines. ......................................................1-56
Turbofan Engines. .........................................................1-57
Turbine Engine Operating Principles. ...........................1-57
Thrust. ...........................................................................1-59
Gas Turbine Engine Performance. ................................1-60
Ram Recovery. ..........................................................1-62

Chapter 2
Engine Fuel and Fuel Metering Systems...........2-1
Fuel System Requirements. ............................................2-1
Vapor Lock. .................................................................2-2
Basic Fuel System. ..........................................................2-2
Fuel Metering Devices for Reciprocating Engines. ........2-3
Fuel/Air Mixtures. .......................................................2-4
Carburetion Principles. ...................................................2-5
Venturi Principles. .......................................................2-5
Application of Venturi Principle to Carburetor. ..........2-6
Metering and Discharge of Fuel. .................................2-6
Carburetor Systems. ........................................................2-8
Carburetor Types. ...........................................................2-9
Carburetor Icing. .............................................................2-9
Float-Type Carburetors. ................................................2-10
Float Chamber Mechanism System. ..........................2-10
Main Metering System. .............................................2-11
Idling System. ............................................................2-12
Mixture Control System. ...........................................2-13
Accelerating System. .................................................2-14
Economizer System. ..................................................2-14
Pressure Injection Carburetors. .....................................2-15
Typical Injection Carburetor. ....................................2-15
Throttle Body. ...........................................................2-16
Regulator Unit. ..........................................................2-16
Fuel Control Unit. .....................................................2-18
Automatic Mixture Control (AMC). .............................2-19
Stromberg PS Carburetor. .............................................2-20
Accelerating Pump. ...................................................2-21
Manual Mixture Control. ...........................................2-21
Fuel-Injection Systems. .................................................2-22
Bendix/Precision Fuel-Injection System. ..................2-22
Fuel Injector. .............................................................2-22
Airflow Section. ........................................................2-22
Regulator Section. .....................................................2-22
Fuel Metering Section. ..............................................2-23
Flow Divider. ............................................................2-23
Fuel Discharge Nozzles. ............................................2-24
Continental/TCM Fuel-Injection System. .................2-25
Fuel-Injection Pump. .................................................2-25
Fuel/Air Control Unit. ...............................................2-27
Fuel Control Assembly. .............................................2-27
Fuel Manifold Valve. ................................................2-28
Fuel Discharge Nozzle. .............................................2-28
Carburetor Maintenance. ...............................................2-30
Carburetor Removal. .................................................2-30
Installation of Carburetor. .........................................2-30
Rigging Carburetor Controls. ....................................2-30
Adjusting Idle Mixtures. ...........................................2-30
Idle Speed Adjustment. .............................................2-32
Fuel System Inspection and Maintenance. ....................2-32
Complete System. ......................................................2-33
Fuel Tanks. ................................................................2-33
Lines and Fittings. .....................................................2-33
Selector Valves. .........................................................2-33
Pumps. .......................................................................2-33
Main Line Strainers. ..................................................2-34
Fuel Quantity Gauges. ...............................................2-34
Fuel Pressure Gauge. .................................................2-34
Pressure Warning Signal. ..........................................2-34
Water Injection Systems for Reciprocating Engines. ..............................................2-34
Turbine Engine Fuel System—General Requirements. ...............................................................2-34
Turbine Fuel Controls. ..............................................2-35
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 4Engine 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
Timing Lights. ...........................................................4-24
Checking the Internal Timing of a Magneto. ................4-25
High-Tension Magneto E-Gap Setting (Bench Timing). ........................................................4-26
Timing the High-tension Magneto to the Engine. .....4-27
Performing Ignition System Checks.........................4-27
Ignition Switch Check. ..............................................4-28
Maintenance and Inspection of Ignition Leads. ........4-28
Replacement of Ignition Harness. .............................4-29
Checking Ignition Induction Vibrator Systems. ........4-30
Spark Plug Inspection and Maintenance. ......................4-30
Carbon Fouling of Spark Plugs. ................................4-30
Oil Fouling of Spark Plugs. .......................................4-30
Lead Fouling of Spark Plugs. ....................................4-31
Graphite Fouling of Spark Plugs. ..............................4-31
Gap Erosion of Spark Plugs. .....................................4-32
Spark Plug Removal. .................................................4-32
Spark Plug Reconditioning Service. ..........................4-33
Inspection Prior to Installation. .................................4-34
Spark Plug Installation. .............................................4-35
Spark Plug Lead Installation. ....................................4-35
Breaker Point Inspection. ..........................................4-36
Dielectric Inspection.................................................4-38
Ignition Harness Maintenance. ..................................4-38
High-Tension Ignition Harness Faults. .....................4-38
Harness Testing. ........................................................4-39
Turbine Engine Ignition Systems. .................................4-40
Capacitor Discharge Exciter Unit.............................4-41
Igniter Plugs. .............................................................4-42
Turbine Ignition System Inspection and
Maintenance. .................................................................4-42
Inspection. .................................................................4-43
Check System Operation. ..........................................4-43
Repair. .......................................................................4-43
Removal, Maintenance, and Installation of Ignition System Components. .......................................4-43
Ignition System Leads. ..............................................4-44
Igniter Plugs. .............................................................4-44
Powerplant Electrical Systems. .....................................4-45
Wire Size. ..................................................................4-45
Factors Affecting the Selection of Wire Size. ...........4-47
Factors Affecting Selection of Conductor Material. ....................................................................4-47
Conductor Insulation. ................................................4-49
Identifying Wire and Cable. ......................................4-50
Electrical Wiring Installation. ...................................4-51
Wire Groups and Bundles. ........................................4-51
Twisting Wires. .........................................................4-52
Spliced Connections in Wire Bundles. ......................4-52
Slack in Wiring Bundles...........................................4-52
Bend Radii. ................................................................4-52
Routing and Installation. ...........................................4-53
Protection Against Chafing. ......................................4-53
Protection Against High Temperature. ......................4-53
Protection Against Solvents and Fluids. ...................4-54
Protection of Wires in Wheel Well Area..................4-54
Routing Precautions. .................................................4-54
Installation of Cable Clamps. ....................................4-54
Lacing and Tying Wire Bundles. ..................................4-55
Single-Cord Lacing. ..................................................4-55
Double-Cord Lacing. .................................................4-56
Lacing Branch-Offs. ..................................................4-56
Tying. ........................................................................4-57
Cutting Wire and Cable. ...............................................4-58
Stripping Wire and Cable. .............................................4-58
Solderless Terminals and Splices. .............................4-59
Copper Wire Terminals. ............................................4-59
Crimping Tools. ........................................................4-60
Aluminum Wire Terminals. ......................................4-60
Splicing Copper Wires Using Preinsulated Wires. ...4-61
Emergency Splicing Repairs. ........................................4-61
Splicing with Solder and Potting Compound. ...........4-61
Connecting Terminal Lugs to Terminal Blocks. ...........4-62
Bonding and Grounding. ...............................................4-62
General Bonding and Grounding Procedures. ...........4-63
Connectors. ...................................................................4-65
Types of Connectors. .................................................4-65
Connector Identification. ...........................................4-65
Installation of Connectors. ........................................4-65
Conduit. .........................................................................4-67
Electrical Equipment Installation. .................................4-67
Electrical Load Limits. ..............................................4-67
Controlling or Monitoring the Electrical Load.........4-67
Circuit Protection Devices........................................4-68
Switches. ...................................................................4-68
Relays. .......................................................................4-69

Chapter 5
Engine Starting Systems. ....................................5-1
Introduction. ....................................................................5-1
Reciprocating Engine Starting Systems. .........................5-2
Inertia Starters. ............................................................5-2
Direct Cranking Electric Starter. .................................5-2
Direct Cranking Electric Starting System for Large Reciprocating Engines. ..................................5-3
Direct Cranking Electric Starting System for Small Aircraft. .........................................................5-7
Reciprocating Engine Starting System Maintenance Practices. ................................................5-7
Troubleshooting Small Aircraft Starting Systems......5-8
Gas Turbine Engine Starters. ..........................................5-8
Electric Starting Systems and Starter Generator Starting System. ............................................................5-10
Troubleshooting a Starter Generator Starting System. ......................................................................5-13
Air Turbine Starters. .....................................................5-13
Air Turbine Starter Troubleshooting Guide. .............5-16
Glossary. ..............................................................G-1
Index. ......................................................................I-1