Operational Aircraft Performance and Flight Test Practices

Description

Operational Aircraft Performance and Flight Test Practices is intended to serve as a single source reference, from the basic theory to practical cases, for certification flight testing and operational performance monitoring. It provides more real-life examples than are offered in traditional textbooks. To this end, the first part of every subject begins with the development of the basic performance equations based on a given set of assumptions. Following this, we deconstruct the maneuver being analyzed to validate its components (create small flight test packages to validate models and expected airplane behavior). Then, flight test considerations are discussed including required instrumentation, flight test risk and risk mitigation, data scatter, data reduction and presentation of the performance information to the flight crew. Several examples of flight test results help the reader better understand what they may be faced with when collecting data to create performance models. There is a major focus on FAA 14 CFR Part 25 certification requirements as a basis for discussion since the format of this set of regulations is publicly available and clearly shows the basic items that go into demonstrating that an airplane is safe to operate. The general approach is also valid for certification under Part 23 or military specifications and, from time to time, the reader will encounter these additional requirements to show variance into airplane certified performance. Throughout the book, readers will find review of accidents and incidents that have occurred on various airplanes. It is not the purpose of this book to assign blame or liability, but rather to share experiences and lessons-learned to hopefully aid in the prevention of future accidents and incidents as well as changes in regulations to continue improving aviation safety. CONTENTS 1 Atmosphere 2 Measuring Altitude 3 Measuring Airspeed 4 Altimetry Error 5 Weight and Balance 6 Lift and Stall 7 Stall Testing 8 Thrust and Drag Modeling 9 Flight Envelope 10 Cruise Performance and Flight Endurance 11 Cruise and Drag Performance Testing 12 Climb Performance 13 Climb Capability OEI 14 Turn Performance and Maneuver Margin 15 Takeoff Performance 16 Takeoff Performance Testing 17 Rejected Takeoff Performance 18 Rejected Takeoff Performance Testing and AFM Takeoff Field Length 19 Landing Performance 20 Landing Performance Testing and AFM Cover Half Title Title Page Copyright Page Contents Acknowledgement Preface Chapter 1: Atmosphere Atmospheric Properties Perfect Gas Atmosphere to 65,617 Feet Standard Atmosphere Atmospheric Ratios Temperature, Pressure, and Density Altitudes Exercises References Chapter 2: Measuring Altitude Introduction Pressure Altitude Radar Altitude GPS Altitude Exercises Reference Chapter 3: Measuring Airspeed Introduction True Airspeed, Speed of Sound, and Mach Number Equivalent Airspeed Calibrated Airspeed Ground and Vertical Speeds Instruments: Airspeed Indicators Exercises Reference Chapter 4: Altimetry Error Indicated Airspeed/Altitude Certification Regulations Flight Testing for Air Data Errors Probe Location: Manufacturing and Maneuver-Based Errors Static Source Error Correction (SSEC) Sensor Accuracy, Precision, Resolution, and Calibration Flight Manual: Presenting the Information to the Flight Crew Unreliable Airspeed (URA) Concluding Remarks Exercise References Chapter 5: Weight and Balance Introduction Weight Breakdown and Definitions Aircraft Weighing: Theory and Practice Center of Gravity: It’s a Balancing Act Lateral CG Vertical CG Mass Moment of Inertia Fuel Weight and CG Passenger Weight Cargo and Checked Baggage Typical Weight and Center of Gravity Envelopes Flight Testing and Flight Test Equipment and Ballast Airplane Weighing Procedures and Documentation Weight a Minute Tracking the BEW In-Service Impact of Weight on Performance: Examples Exercises References Chapter 6: Liftft and Stall Basic Airplane Geometry Lift and Lift Equation Lift Curve and Lift Distribution Lift Limit: Aerodynamic Stall Display of Angle of Attack in the Cockpit Icing Ice Protection Systems Manufacturing Tolerance: An Aerodynamic Perspective References Chapter 7: Stall Testing Importance of a Stall Program on Airplane Certification Defining Stall from a Certification Point of View Stall Speed Testing Creating a Stall Speed Model Presenting the Information to the Flight Crew Exercise References Chapter 8: Thrust and Drag Modeli Drag Model Slow Flight Speed Domain Thrust Model Thrust Summary Thrust-Drag Bookkeeping References Chapter 9: Flight Envelope A Regulation-Based Limit Low-Speed Limit High-Speed Limit Maximum Altitude Temperature Envelope Flaps Out and Gear Down Envelopes Placard Speeds Reduced Vertical Separation Minimum (RVSM) Conclusion References Chapter 10: Cruise Performance and Flight Endurance Defining Range Useful Parameters Specific Air Range (SAR) Range Equation: Turbojet/Turbofans Range Equation: Reciprocating/Turboprop Fuel Reserves Impact of Wind on Range Payload-Range Diagram Flight Endurance Electrical Propulsion: A Step Change? Hybrid-Electric: An Evolutionary Change The Case for the Reduced Energy Plane: The Hydrogen Plane References Chapter 11: Cruise and Drag Performance Testing Creating a Drag Model from Flight Test Results Testing for Low-Speed Drag Testing for High-Speed Drag Testing for SAR Testing for Zero Fuel Level Presenting the Information to the Flight Crew Fuel (Energy) Management and Conservation Chapter 12: Climb Performance Developing a Climb Performance Model Factors Influencing Climb Performance Climb Schedules Descending Flight Load Factor and Flight Path Variation Energy Height Certification Requirements Flight Test and Data Reduction Presenting the Information to a Flight Crew Exercise Chapter 13: Climb Capability OEI Impact of One Engine Inoperative (OEI) on Climb Performance Certification Regulations: Part 25 Transport Category Airplanes Flight Test and Check Climbs Presenting the Takeoff Weight Limited by Climb Requirements to a Flight Crew Obstacle Clearance Presenting the Climb Information for Obstacle Clearance to a Flight Crew Gliding Flight Exercise Reference Chapter 14: Turn Performance and Maneuver Margin Building a Basic Model Special Cases for Turn Performance Altitude Effects on Sustainable Turn Performance Flight Envelope Energy Maneuverability Inner Wing Stall in a Turn Maneuver Margin and Certification Regulations Buffet Envelope Unrestricted Turn Performance Turn Performance under OEI Conditions Exercises Reference Chapter 15: Takeoff Performance Takeoff Distance Definition Basic Takeoff Performance Model: Takeoff Segments Takeoff Speed Summary Takeoff Distance, Acceleration-Go Certification Regulations: Part 25 Transport Category Airplanes Exercises Chapter 16: Takeoff Performance Testing Takeoff Distance Modeling Minimum Control Speed: Air VMCA Certification Regulations: Robustness of Takeoff Procedure Takeoff Performance Testing: Risks and Mitigations Exercise Reference Chapter 17: Rejected Takeoff Performance Why Reject a Takeoff? RTO Distance Definition Stopway Runway Safety Area (RSA) Engineered Materials Arresting Systems (EMAS) for Airplane Overruns References Chapter 18: Rejected Takeoff Performance Testing and AFM Takeoff Field Length Braking Performance and Testing RTO Testing for Minimum Control Speed, Ground RTO Testing Maximum Kinetic Energy Testing (Max KE) Maximum Wheel Speed Airplane Flight Manual: Takeoff Field Length (TOFL) References Chapter 19: Landing Performance Basic Modeling Air Segment Transition Segment Ground Run Segment Total Landing Distance Operational Requirements Exercises References Chapter 20: Landing Performance Testing and A Preparing for a Landing Distance Test Campaign Testing for the Air Segment Testing for the Transition Segment Testing for the Ground Run Segment Total Landing Distance Presenting the Information to the Flight Crew Time of Arrival Landing Performance Steep Approach Transport Canada Steeper Requirements Reference About the Author Index Supporting Materials