Flight Testing: Analysis of the Spin Dynamics of a Single–Engine Low–Wing Aeroplane

About this book
Contents
1 Introduction
	1.1	The Problem with Spinning
	1.2	Scope of the Research
	1.3	Reasoning for the Research and Its Relevance
	1.4	Aim of the Study
	1.5	Research Questions and Subsequent Observations
	1.6	Preparation for the Flight Testing
	1.7	Structure of the Work
	1.8	Contributions to State of the Art/Research
2 Literature Review
	2.1	Introduction into the Literature Review
	2.2	Civil and Military Spin Training Material
	2.3	The Phases of a Spin
	2.4	Measurement Techniques for Spinning
		2.4.1	Experimental Measurements
		2.4.2	Theoretical Models
			2.4.2.1 Force and Moment Models
			2.4.2.2 Area Models for Spin Safety
			2.4.2.3 Computational Programmes for Modelling High Angle of Attack Cases
		2.4.3	Flight Tests
			2.4.3.1 Low Wing Aircraft
			2.4.3.2 High Wing Aircraft
	2.5	Effect of Aeroplane Shape on Spin Behaviour
		2.5.1	Wing Leading Edge Changes
		2.5.2	Control Surface Effectiveness
		2.5.3	Tail Effects
	2.6	Spin Parameters
	2.7	Spin Accident Statistics/Safety
	2.8	Spin Related Regulations
	2.9	Sources of Human Factors During Spinning
	2.10	Conclusions of the Literature Review
3 Measurement System for Spin Test Data Acquisition
	3.1	Introduction
	3.2	System Requirements
		3.2.1	What Needs to be Measured?
		3.2.2	What Precision is Needed for the Parameters of Interest?
		3.2.3	What Ranges are Needed for the Parameters of Interest?
		3.2.4	What Resolution is Needed for the Parameters of Interest?
	3.3	The Measurement System
	3.4	Data Acquisition
	3.5	Installation of the Measurement System in the Research Aeroplane
		3.5.1	Installation of displacement sensor system
		3.5.2	Installation of the Inertial Measurement Unit (IMU)
		3.5.3	Installation of the Wing Booms and Wind Vanes
		3.5.4	Installation of the Data Acquisition Computer, Pressure Sensors and Uninterrupted Power Supply (UPS)
		3.5.5	Wiring of the Measurement System
	3.6	Calibration and Data Validation of the Sensor System
		3.6.1	IMU Data Calibration
		3.6.2	Wind Vane Sensor Calibration
		3.6.3	Static Pressure Sensor Calibration
		3.6.4	Calibration of Fuel Gauges
	3.7	Conclusions
4 Preparation of the Aeroplane and the Spin Trials
	4.1	Introduction
	4.2	Modification and Inspection of the Utilized Aeroplane
	4.3	Suction System Modification
	4.4	Wing Spar Inspection
	4.5	Choice of the Relevant and Investigated Parameters
	4.6	Flight Envelope Determination Regarding Masses and Centre of Gravity Positions, Limit of the Tests and Choice of the Test Points Within the Defined Flight Envelope
	4.7	Legal Basis for Test Flights
	4.8	Flight Trial Procedures and Conditions
	4.9	Conclusions
5 Spin Description
	5.1	Introduction
	5.2	Spin Description on the Basis of the Measured Flight Test Data
	5.3	Example of a Spin Entry
	5.4	Example of a Developed Spin
		5.4.1	Angle-of-Attack and Angle-of-Sideslip Behaviour
		5.4.2	Acceleration Behaviour Around all Three Axes
		5.4.3	Aeroplane’s Attitude and Turn Rate Behaviour (Φ with p, Θ with q, Ψ with r)
	5.5	Example of a Spin Recovery
	5.6	High Frequency Data Fluctuation
	5.7	Conclusions of the Spin Description
6 Mathematical Spin Test Data Analysis
	6.1	Introduction into the Mathematical Spin Test Data Analysis
	6.2	Evaluation and Processing of the θ-Values
	6.3	Pitch Angle Data Analysis
	6.4	Observation 1: The Second Minimum Value of the Pitch Down (ln_Theta) Function Always Produces the Highest Negative Value.
	6.5	Observation 2: Independent of the aeroplane’s Mass and CG Position, the Pitch Angle (ln_Theta) Approximates to a Characteristic Value
	6.6	Observation 3: Maximum Yaw Rate (ln_r) Changes with CG Position and Mass
	6.7	Observation 4: The Yaw Rate (ln_r) Oscillation Changes with CG Position or Mass
	6.8	Observation 5: Maximum Difference in Angle of Attack Values Between Left and Right Wings Leads to a Maximum in Roll Rates (alpha_le_c—alpha_ri_c; ln_p)
	6.9	Observation 6: Rate of Roll (ln_p) Changes with CG Position and Aeroplane’s Mass
	6.10	Observation 7: Total Angular Velocity Ω Changes with CG Position and Mass
	6.11	Observation 8: Recovery Time Becomes Shorter with CG Moving Backwards
	6.12	Observation 9: The Spin Behaviour of the Fuji FA 200 – 160 Can Be Generalised for Single-Engine Low-Wing Aeroplanes
	6.13	Conclusion of the Spin Test Data Analysis
		6.13.1	Conclusions of the Observations
7 Flight Test Data Comparison
	7.1	Introduction
	7.2	Comparison of Angle-Of-Attack at the Centre of Gravity
	7.3	Comparison of Angle-Of-Sideslip at the Centre of Gravity
	7.4	Comparison of Pitch Rate
	7.5	Comparison of Yaw Rate
	7.6	Comparison of Roll Rate
	7.7	Conclusions
8 Conclusion
	8.1	Main Conclusions, Contributions and Impact
		8.1.1	Observation 1: The Second Minimum Value of the Pitch Down (Θ) Function Always Produces the Highest Negative Value
		8.1.2	Observation 2: Independent of the Aeroplane’s Mass and CG Position, the Pitch Angle (Θ) Approximates to a Characteristic Value
		8.1.3	Observation 3: Maximum Yaw rate (ln_r) Changes with CG Position and Mass
		8.1.4	Observation 4: The Yaw Rate (ln_r) Oscillation Changes with CG Position or Mass
		8.1.5	Observation 5: Maximum Difference In AoA Values Between Left and Right Wings Leads to a Maximum in Roll Rates (alpha_le_c – alpha_ri_c; ln_p)
		8.1.6	Observation 6: Rate of Roll (ln_p) Changes with CG Position and Aeroplane’s Mass
		8.1.7	Observation 7: Total Angular Velocity Ω Changes with CG Position and Mass
		8.1.8	Observation 8: Recovery Time Becomes Shorter with CG Moving Backwards
		8.1.9	Observation 9: The Spin Behaviour of the Fuji FA 200—160 can be Generalised for Single-Engine Low-Wing Aeroplanes
	8.2	Publications
9 Recommendations for Further Work
10 General Understanding of Spinning and Supporting Material
	10.1	General Understanding of Spinning
		10.1.1	Phases of a Spin
		10.1.2	The Steady Erect Spin
		10.1.3	Motion of the Aeroplane
		10.1.4	Balance of Forces in the Spin
		10.1.5	Effect of Attitude on Spin Radius
		10.1.6	Angular Momentum
		10.1.7	Moment of Inertia (I)
		10.1.8	Inertia Moments in a Spin
		10.1.9	Factor Contributions of Aerodynamic Moments
		10.1.10 Balance of Moments
		10.1.11 Effects of Controls in Recovery from a Spin
		10.1.12 Effect of Ailerons
		10.1.13 Effect of Elevator
		10.1.14 Effect of Rudder
		10.1.15 Inverted Spin
		10.1.16 Oscillatory Spin
		10.1.17 Conclusion (of Sect. )
	10.2	Gyroscopic Cross-Coupling Between Axes
		10.2.1	Introduction
		10.2.2	Inertia Moments in a Spin
	10.3	Example of a Certification Spin Test Planning
		10.3.1	Introduction
		10.3.2	References
		10.3.3	Purpose and Test Description
		10.3.4	Configuration
		10.3.5	Conformity
		10.3.6	Instrumentation and Data
		10.3.7	Safety
		10.3.8	Processing of a Spin Test Matrix
		10.3.9	Envelope Range
		10.3.10 Spin Test Matrix
		10.3.11 Procedures and Acceptance Criteria
	10.4	Excerpt from the Current Certification Specification EASA CS 23 on Spinning
	10.5	Technical Data of the Research Aeroplanes
		10.5.1	NASA Research Aeroplane, Piper PA 28 RT-201 T Turbo Arrow IV
		10.5.2	Research Aeroplane of the Collaborating ATO, Fuji FA-200-160
	10.6	Aeroplane Categories
	10.7	Calibration Protocols
	10.8	Mathematical Methods
		10.8.1	General Methods
			10.8.1.1 Gradient Descent
			10.8.1.2 Smoothing, Detection of Relative Maximum/Minimum of a Time Series (yi)
			10.8.1.3 Numerical Derivation
			10.8.1.4 Periodic Linear Regression Model
			10.8.1.5 Discrete Fourier Transformation (DFT)
			10.8.1.6 Linear Homogenous Ordinary Differential Equation of Second Order
		10.8.2	Statistical Methods
			10.8.2.1 Multi-Linear Regression, Coefficient of Determination (Multiple Regression Coefficient)
			10.8.2.2 Coefficient of Determination
			10.8.2.3 Analysis of Variance (ANOVA)
			10.8.2.4 Wilcoxon—Test
			10.8.2.5 Confidence Interval for Values Predicted by Linear Regression
Glossar
References and Bibliography