||An Investigation of Flight Data via Modern Analysis Methods for Civil Transport During Landing Phase
||Department of Aerospace Engineering
flight operations quality assurance
Hilbert - Huang Transform
flight data analysis
||本研究將波音747型機之兩筆正常航班資料及一筆異常航班資料由飛行操作品質系統(Flight Operations Quality Assurance, FOQA)取出之飛行數據，利用小波法(Wavelet Transform)及希爾伯特-黃轉換(Hilbert-Huang Transform, HHT)加以分析。考慮許多相關程度高的參數，如空速、下降率、引擎推力、攻角、風速、風向等，從原始訊號分解出不同頻率之訊號，觀察訊號變化，研判出訊號有研究價值的部分，藉由兩個理論方法分析這些參數，比較三個航班之異常訊號。
本研究主要利用飛行力學以及推估導航之系統概念，藉由FOQA系統裡快速資料記錄器(Flight Data Recorder, FDR)所提供的降落飛行資料，重新建立二維平面風場。再將與降落有關的參數放進兩種理論方法加以分析。首先利用HHT解析訊號，HHT是一個優秀的工具，能闡述非線性和非平穩時間序列，產生不同頻率之訊號，與傳統方法相比，在隱藏物理現象的理解上，HHT具有更高頻譜的分辨率。HHT可將原始訊號將被分解出好幾個震盪模組(Intrinsic Mode Functions, IMF)，層層抽出，更重要的是了解分離後訊號背後代表之物理意義。其次有別於以往如傅立葉轉換(Fourier transform , FT)，短時快速傅立葉轉換(Short-time Fourier transform, STFT)等固定窗下的頻率解析，小波法(Wavelet transform)套用母小波來分析一段訊號。而不同高低之頻率需求不同長短的窗型來解析，因此小波法利用Morlet型母小波調整窗大小來達到解析高低頻率之間的缺點，因此解析度將比傳統方法得到在頻域上更突出的結果。
||In this research, three flight data of Boeing747-400 including two normal and one abnormal are analyzed, which derived from Flight Operations Quality Assurance (FOQA), by using Wavelet Transform and Hilbert-Huang Transform methods. Considering the tremendous amount of relevant parameters involved, such as true airspeed, vertical speed, thrust, angle of attack, wind speed, wind direction, etc., we need to first decompose these engineering data to different frequencies inside the signals, observe their changes, and acquire valuable and meaningful flight interpretations. The main purpose for this work is to figure out unusual warning by contrasting with the analyses via two theoretical methods.
In this study, we re-establish two-dimensional horizontal wind fields by data taken from Flight Data Recorder (FDR) via the equations of flight mechanics and the system of dead-reckoning. Then we could analyze parameters of wind speed and wind direction into HHT and Wavelet Transform formats. HHT is a modern tool for non-linear and non-stationary time series interpretation, and has a high-resolution spectrum compared to traditional methods for understanding background physical meaning. In the cases studied, HHT gave results much sharper than those from any of the traditional analytical methods in the time-frequency-energy representations. Moreover, traditional methods such as Fourier transform (FT) and short-time fast Fourier (STFT), utilizing fixed window to analyze frequencies in signal, but Wavelet Transform applying a dilation window function to fit the length of the data, and it really work out on decomposing from high-frequency to low-frequency oscillation in signals. Therefore, Wavelet Transform obtains more prominent results in the frequency domain.
Data generated consequences of HHT and Wavelet method, compared with each other, in order to see clearly the results which were demonstrated. Comprehensive the interpretations of two methods combined with the report of Aviation Safety Council give us more precise analytical results in landing profile and physical phenomena. Moreover, our expectation is to obtain the "prediction warning message" which would pose a serious threat to flight safety before the occurrence of accident/incident from observing the abnormal parameters data set.
||List of Contents
List of Tables vii
List of Figures viii
Chapter 1 Introduction 1
Chapter 2 Background Research and Literature Review 7
2.1 Accident Investigation Factual Data Collection Group Report 7
2.2 Aviation Occurrence Categories 8
2.3 Factors of Flight Safety 10
2.4 Stabilized Approach 14
2.5 Introduction to Flight Quality Operation Assurance (FOQA) 16
2.6 Introduction to Hilbert-Hung Transformation (HHT) 18
2.7 Introduction of Wavelet Transform 21
Chapter 3 Data Processing and Mathematical Method 28
3.1 Source and Types of Flight Data 28
3.2 Horizontal Wind Field 29
3.2.1 Estimate Sideslip Angle β 30
3.2.2 Estimate Angle of Attack α 36
3.3 Theoretical Method: Hilbert-Hung Transformation (HHT) 37
3.3.1 The Empirical Mode Decomposition (EMD) 37
3.3.2 Hilbert Spectral Analysis (HSA) 41
3.3.3 Completeness of Hilbert Transform 42
3.4 Theoretical Method: Wavelet transform 43
3.4.1 Morlet wavelet transform 43
3.4.2 Enhanced Morlet transform 46
3.4.3 Gabor transform 46
Chapter 4 Result and Discussion 57
4.1 Validation of Horizontal Wind Field 57
4.2 Parameters Analysis via Hilbert-Huang Transform and Wavelet Transformation 59
Chapter 5 Conclusion 78
Appendix A Equations of re-establishing wind field 89
Appendix B Original FDR Readout Parameters (Engineering Data) 91
Appendix C 98
List of Tables
Table 2.1 Minimum stabilization heights 23
Table 2.2 Excessive flight-parameter-deviation callouts 23
Table 3.1 The specifications of overall airplane 47
Table 3.2 The parameters of FDR recorded 49
Table 4.1 Total time in landing 62
Table 5.1 Parameters of three specific time 80
List of Figures
Figure 2.1Aviation occurrence categories by Boeing 25
Figure 2.2 The rate of primary causes of accidents 25
Figure 2.3 Fatal Accidents and Onboard Fatalities by Phase of Flight 26
Figure 2.4 The investigations of accidents and the statistical classification of the accidents causes of nationality civil air transport fixed-wing aircraft 26
Figure 2.5 The aiming point 27
Figure 2.6 The shape of a runway 27
Figure 3.1 Principal dimensions of B747-400 51
Figure 3.2 Principal dimensions of B747-400 52
Figure 3.3 Body station diagram 53
Figure 3.4 Body station diagram 53
Figure 3.5 Magnetic declination data by Nationnal Geophysical Data Center 54
Figure 3.6 Geometry of dead reckoning 55
Figure 3.7 The typical type of EMD procedure 55
Figure 3.8 The HSA procedure of HHT 56
Figure 4.1 (a) Wind speed determined by N3 with sideslip angle comparing with sideslip angle ignored (b) Factors of case N3 (c) Wind speed determined by N3 without singularity point 64
Figure 4.2 Wind speed determined by Event with sideslip angle comparing with sideslip angle ignored 64
Figure 4.3 Wind speed determined by Event with AOA 9 seconds damping and comparing sideslip angle with sideslip angle ignored 65
Figure 4.4 (a)Wind speed determined by Event with sideslip angle and compare AOA 4 seconds damping with 9 AOA seconds damping (b)Comparison of wind speed damping in 9 seconds or not 66
Figure 4.5 Wind speed below 50 feet of Event comparing with the AWOS 66
Figure 4.6 True airspeed analysis by HHT 67
Figure 4.7 Wind speed analysis by HHT 68
Figure 4.8 Wind speed analysis by Wavelet 69
Figure 4.9 Wind direction analysis of HHT 70
Figure 4.10 Wind direction analysis of Wavelet 71
Figure 4.11Lateral acceleration analysis by HHT 72
Figure 4.12 Lateral acceleration analysis by Wavelet 73
Figure 4.13 Radio height analysis via HHT 74
Figure 4.14 Radio height analysis via Wavelet 75
Figure 4.15 AOA analysis of HHT 76
Figure 4.16 AOA analysis by Wavelet 77
Figure 5.1 Comparison of on-board FMS wind, tower wind and actual wind encountered by an approaching aircraft 82
Figure 5.2 Rudder input analysis of HHT 83
Figure 5.3 Rudder input analysis by Wavelet 84
 Aviation Safety Council Taiwan, Republic of China, “Runway Excursion in Touchdown on Runway During Landing, EVA Airlines Flight 701, Boeing 747-400, Taoyuan Airport, Taoyuan, Taiwan, September 9, 2010, ” Aircraft Accident Report, Taipei, 105 Taiwan, R. O. C., 2011.
 Boeing Commercial Airplanes, “Statistical Summary of Commercial Jet Airplane Accidents Worldwide Operations 1959 – 2012,” Seattle, Washington, U.S.A., Aug. 2013.
 Lin, E. M. K. H., Lowe, W.D., and Sheppard, P. F. , “Report of the Board of Review on the Accident to Boeing MD-11 B-150 at Hong Kong International Airport on 22nd August 1999,” Hong Kong SAR, Nov. 2004.
 Aviation Safety Council Taiwan, Republic of China, “Crashed on a Partially Closed Runway During Takeoff, Singapore Airlines Flight 006, Boeing 747-400, 9V-SPK, CKS Airport, Taoyuan, Taiwan, October 31, 2000, ” Aircraft Accident Report, Taipei, 105 Taiwan, R. O. C., 2002.
 Wan, T., “Aviation Safety Analysis,” Tamkang Univ., 2010.
 Boeing Commercial Airplanes, “Statistical Summary of Commercial Jet Airplane Accidents Worldwide Operations 1959-2001,” Seattle, Washington, U.S.A., June 2002.
 Aviation Safety Council Taiwan, Republic of China, “102 Annual Report of Aviation Safety Council,” Taipei, 105 Taiwan, R. O. C., 2013.
 Yang, C. L., “Three Hidden Worries of Flight Safety,” Science Development, Taipei, Taiwan, Mar. 2014.
 Flight Safety Foundation, “FSF ALAR Briefing Note 7.1-Stabilized Approach," Flight Safety Digest, Alexandria, U.S.A., Aug.-Nov. 2000.
 Federal Aviation Administration, “ALC-34: Maneuvering: Approach and Landing,” Online available :
Airbus Customer Services Flight Operations Support and Services, “Approach Techniques Flying Stabilized Approaches," Flight Operations Briefing Notes, Blagnac, France, Oct. 2006.
Boeing Commercial Airplanes Airport Technology, “Airport Reference Code and Approach Speeds for Boeing Airplanes,” Mar. 2011.
 Wan, T., “An Investigation Report of Taiwan’s Airlines using FOQA System,” Engineering and Technology Promotion Center, National Science Council of ROC, Jan. 2001, pp. 1-10.
 Huang, N. E., “Introduction to the Hilbert-Huang Transform and Its Related Mathematical Problems,” The Hilbert-Huang Transform and Its Applications, 1st ed., Covent Garden, London, 2005, pp. 1-26.
 Huang, N. E. and Shen, S. P., The Hilbert-Huang Transform and Its Applications, 1st Edition, Covent Garden, London, 2005.
 Wang, G., Chen, X. Y., Qiao, F. L., Wu, Z. and Huang, N.E., “On Intrinsic Mode Function,” Advances in Adaptive Data Analysis, Vol. 2, No. 3, World Scientific Publishing Company, 2010, pp. 277-293.
 Huang, N. E., Wu, Z., Long, S. R., Arnold, K. C., Chen, X., and Blank, K., “On Instantaneous Frequency,” Advances in Adaptive Data Analysis, Vol. 1, No. 2, World Scientific Publishing Company, 2009, pp. 177-299.
 Cheng, N., “An Investigation of Flight Vehicle Performance Parameters via the Modern Hilbert-Huang Transform and the Improved Sequence Alignment Methods,” MS Thesis, Tamkang Univ., 2012.
 Coughlin, K. and Tung, K. K., “Empirical Mode Decomposition and Climate Variability,” Hilbert–Huang Transform and its Applications, 1st Edition, Covent Garden, London, 2005, pp. 149–168.
 Choen, L., “Time-frequency Distributions-a Review,” Proceeding of the IEEE, Vol. 77, No. 7, 1989.
 Oehlmann, H., Brie, D., Tomczak, M. and Richard, A., “A Method for Analyzing Gearbox Faults Using Time-Frequency Representations,” Mechanical Systems and Signal Processing, Vol. 11, 1997, pp. 529-545.
 Staszewski, W. J., Worden, K., and Tomlinson, G. R., “Time-Frequency Analysis in Gearbox Fault Detection Using the Wigner-Ville Distribution and Pattern Recognition,” Mechanical Systems and Signal Processing, Vol. 11, 1997, pp. 673-692.
 Gabor, D., “Theory of Communications,” Journal of the Institution of Electrical Engineers, Vol. 93, No. 4, 1946, pp. 429-457.
 Al-Badourl, F., Chedect, L., and Suna, M., “Non-Stationary Vibration Signal Analysis of Rotating Machinery via Time-Frequency and Wavelet Techniques,” Information Sciences Signal Processing and their Applications, 2010, pp. 21-24.
 Brenner, M., “Wavelet-Processed Flight Data for Robust Aeroservoelastic Stability Margins,” Journal of Guidance, Control, and Dynamics, Vol. 21, No. 6, 1998, pp. 823-829.
 Lin, J. and Qu, L., “Feature Extraction Based on Morlet Wavelet and Its Application for Mechanicla Gault Diagnosis,” Journal of Sound and Vibration, Vol. 234, 2000, pp. 135-148.
 Boeing Commercial Airplanes, “Dimensions and Areas,” Boeing 747Maintenance Manual, Boeing Commercial Airplanes Press, 1999, Ch. 6, pp. 201-209.
 Kayton, M. and Fried, W. R., “Dead-Reckoning Computation,” Avionics Navigation System, the United States of America, A Willey-Interscience Press, 1996, pp. 29-30.
 Kevin, G., “Method to Calculate Sideslip Angle and Correct Static Pressure for Sideslip Effects Using Inertial Information,” Canadian Patent, Canadian, Feb. 2002.
 Roskam, J., “Airplane Flight Dynamics and Automatic Flight Controls,” Ottawa, Kansas, Roskam Aviation and Engineering Corporation Press, 1979.
 Federal Aviaiton Administration, “Statistical Data for the Boeing-747-400 Aircraft in Commercial Operations,” Final Rep, Office of Aviation Research, Washington, D.C., Jan. 2005.
 Toll, T. A. and Queijo, M. J., “Approximate Relations and Charts for Low-speed Stability Derivatives of Swept Wings,” National Advisory Committee for Aeronautics, No. 1581, May 1948.
Smetana, F. O., Computer Assisted Analysis of Aircraft Performance Stability and Control, McGraw-Hill Press, 1984.
 Campbell, J. P., and McKinney, M.O., “Summary of Methods for Calculating Dynamic Lateral Stability and Response and for Estimating Lateral Stability Derivatives,” NACA Rep. 1098.
 Haung, J. M., “Time-Frequency Analysis of Acoustic and Vibration Data,” MS Thesis, National Cheng Kung Univ., 2007, pp. 17-21.
 Carmona, R., Hwang, W. L., and Torresani, B., “Practical Time-Frequency Analysis, Gabor and Wavelet Transforms with in Implementation in S,” Academic Press, N. Y., 1998.
 Boashash, B., “Time-Frequency Signal Analysis: Methods and Applications,” Longman-Cheshire, Melbourne, Australia, 1992.
 Jeng, Y. N., Yang, T. M., and Wu, C. H., “Low-Frequency Analysis of Acoustic and Vibration Data of a Remote Control Electronic Helicopter,” AIAA-2009-1155, Jan. 2009.
 Van Es, G.W.H., and Karwal, A.K., “Safety aspects of tailwind operations,” National Aerospace Laboratory NLR, Netherland, Jan. 2001.
 Van Es, G.W.H., “NGW-Near-Ground Wind Gust Detection,” National Aerospace Laboratory NLR, Netherland, Oct. 2012.