Aircraft Systems (eBook)

Series Preface xiii

About the Authors xiv

Preface xv

1 Introduction 1

1.1 Which Are the Airframe Systems? 2

1.2 Aircraft Systems Design Processes and Aircraft- Level Considerations 2

1.3 Systems Integration 2

Bibliography 5

2 Airframe Systems Design Process 6

2.1 Introduction 6

2.1.1 Systems Design Approach 6

2.1.2 Safety Assessment Philosophy 7

2.1.3 Aircraft Systems Design Methods 8

2.1.4 Sae Arp4754a 8

2.1.5 Sae Arp4761 9

2.2 Requirements Capture 9

2.3 System Safety Assessment 11

2.3.1 Functional Hazard Assessment 11

2.3.2 Development Assurance Process and Levels 13

2.3.3 Fault Tree Analysis 14

2.3.4 Failure Modes and Effects Analysis 15

2.4 System Architectures 16

2.4.1 Representing Architectures 17

2.4.2 Architectures for Analysis 18

2.5 Systems Design for Maintainability 19

2.5.1 Maintenance Cost Estimation 20

2.5.2 Accessibility 21

2.5.3 System Ageing and Obsolescence 23

2.6 Aircraft Level Trade- off Analysis 25

2.6.1 Fuel Penalties 25

2.7 Cost 31

2.7.1 Subsystem Cost Breakdown 31

2.7.2 Estimation Approaches 33

2.8 Summary 35

References 35

3 Aircraft Secondary Power Systems 37

3.1 Introduction 37

3.2 Secondary Power Forms 37

3.2.1 Pneumatic Power Systems 37

3.2.2 Hydraulic Power Systems 39

3.2.3 Electrical Power Systems 40

3.2.4 Variable- Frequency AC 41

3.2.5 Fixed- Frequency AC 41

3.2.6 High- Voltage dc 41

3.2.7 Low- Voltage dc 41

3.3 Secondary Power Sources 42

3.3.1 Aircraft- Level Effects 42

3.3.2 Advantages and Disadvantages 43

3.3.3 Trade Study 44

3.3.4 Main Engines 45

3.3.5 Auxiliary Power Units 46

3.3.6 Ground Power Units 47

3.3.7 Ram Air Turbines 48

3.3.8 Emergency Power Units 49

3.3.9 Stored Energy and Batteries 49

4 Aircraft Pneumatic Power Systems 51

4.1 Introduction 51

4.2 The Requirements for Aircraft Pneumatic Power Systems 51

4.2.1 Airworthiness Requirements 52

4.3 Bleed Air Systems Design 53

4.4 Bleed Air Systems Components 54

4.4.1 Pneumatic Valves 54

4.4.2 Pre- coolers 54

4.4.3 Ducting 55

4.5 The Use of Bleed Air 56

4.5.1 Engine Starting Systems 56

4.5.2 Engine Thrust Reversing and Variable Nozzle Geometry Systems 57

4.5.3 Pitot- Static System 57

4.6 Boeing 767 Pneumatic System 57

Bibliography 59

5 Hydraulic Power Systems 60

5.1 Introduction 60

5.2 Hydraulic System Components 61

5.2.1 Hydraulic Fluids 61

Table of Contents ix

5.2.2 Hydraulic Pumps 63

5.2.3 Hydraulic Pumps for Low- Pressure Applications 64

5.2.4 Hydraulic Pumps for High- Pressure Applications 65

5.2.5 Hydraulic Piping 68

5.2.6 Reservoirs 70

5.2.7 Filters 72

5.2.8 Accumulators 73

5.2.9 Pressure Control Valves 74

5.2.10 Heat Exchangers 75

5.2.11 Power Control Units 76

5.3 Hydraulic System Aircraft Applications 78

5.3.1 Boeing 737 Hydraulic System 78

5.3.2 BAE Systems Hawk Hydraulic System 80

5.4 Requirements, System Design, Analysis and Sizing 82

5.4.1 Requirements Definition 82

5.4.2 Performance Requirements Analysis 82

5.4.3 Architecture Definitions 85

5.4.4 System Simulation and Control 87

5.5 Summary 89

References 89

6 Aircraft Electrical Power Systems 90

6.1 Introduction 90

6.2 The R...