DOTIFAAICT-91I32 Engine Bird Ingestion FAA Technical Center Atlantic City International Airport N.J. 08405 Experience of the Boeing 737 This document is available to the U.S. U.S. Department of Transportation Federal Aviation Administration This document is disseminat ?d under the sponsorship of the U .S. Department of ~rans$Urtationin the interest of information exchange. The United States Government assumes no liability for the cor,~entsor use thereof. The United States Government does not endorse products or manufacturers. Trade or mariufacturers' names appear herein solely because they are considered essential to the objective of this report. Technical Report Documentation Page -----.--- -----.--- -- 1. Report No. ~~r(..sCotolos No. DOT/FAA/CT--91132 - - 4. Tttle ond Subtatle THE ENGINE BIRD INGESTION EXPERIENCE OF THE BOEING-737 -July 1992 -. -- -- iIRCRAFT -- EXPANDED DATA BASE (October 1986 - September 6 PorformfingOrpontzot~on Code 1989) -------. Periorm*ng Orgon~xot~onReport NO -- p----.----7 8. 7 Author's) i Peter W. Hovey, Donald A. Skinn, and Joseph J. Wilson* I UDR-TR-91-125 --- I 9. Perforrn~naOram~xot~en Name ond Address 1 10 Work Un~tNo (TRAIS) University of Dayton Research Institute - Structural Integrity Division 11 Contract or Gront No. 300 College Park (JPC 201) DTFA03-88-C-00024 Dayton, OH 45469-0120 -) 13.Final Type ofReport: Report ond P-r80dMediumILarge Covered 12. soon so ran^ Agency Nomo ond Address I=-- U.S. Department of Transportation Inlet Area Engines Federal Aviation Administration -- -- Technical Center Atlanric Ciry International Airport, NJ 08405 ACD-210 - - L-- - - 15 Supplsrnent~r~Not*s WOTR: Joseph J. Wilson; Project Manager: Bruce C. Fenton, Tech. Center DOTIFAAICT-89/16 covers the period from October 1986 to September 1987 DOTIFAAJCT-89/29 covers the period from October 1986 to September 1988 DOTIFAAICT-90128 covers the period from October 1986 to September 1989 The Federal Aviation Administration (FAA) Technical Center initiated a study in October 1986 to determine the numbers, weights, and species of birds which are being ingested into medium and large inlet area turbofan engines and to determine what. damage, if any, results. bird ingestion data were collected for the Boeing-737 model aircraft which llses either the Pratt and Whitney JT8D medium inlet area turbofan engine or the CFM International CFM56 large inlet area turbofan engine. This report analyzes the entire 3 years of data collected by the engine manufacturers, the FAA, and the International Civil Aviation Organization (ICAO) during the period from October 1986 through September 1989. 'robability of Zngestfon Document is available to the public ;taristical Analysis through the National. Technical Information Iird Ingestion .JT8D Service, Springfield, VA 22161 'urbine Engine CFM56 Unclassified Unclassified I - - Form DOT F 1700.7 (8-72) Reproduction of completed pope authorized FOREWORD This final report provides descriptive and statistical analyses of the data collected over a 3-year period on bird ingestion experiences for the B737 aircraft. The data described in this report were collected under separate Federal Aviation Administration (FAA) contracts with the engine manufacturers, by the FAA, and by the International Civil Aviation Organization (ICAO). This is the second report on the 3-year data collection period. At the time when the first report (number DOT/FAA/CT-90128)was prepared, the ICAO bird ingestion data were not available for the full 3-year period. This report represents an update of the first: report with the ICAO data included in the descriptive and statistical analyses. The report was prepared by the University of Dayton under Department of Transportation, Federal Aviation Administration Contract DTFA03-88-C-00024. The principal investigator at the University of Dayton was Dr. Peter W. Hovey, and computer support was provided by Mr. Donald A. Skinn. Mr Joseph Wilson was co-author and the technical project monitor for the FAA during the preparation of the report. TABI.,E OF CONTENTS --PAGE EXECUTIVE SUMMARY 1 INTRODIJCTION 1.1 Background 1.2 Objectives 1.3 Organization of Report 2 AIRCRAFT OPERATIONS AND ATRPORT OPERATIONS 3 CHARACTERISTICS OF INGESTED BIRDS 4 INGESTION RATES 4.1 Ingestion Rate Estimates 4.2 The Poisson Process 4.3 Validity of the Poisson Process Model for Bird Ingestions 4.4 Inlet Area Effect on Ingestion Rates 5 AIRPORT BIRD INGESTTON EXPERIENCE 6 ENGINE DAMAGE DESCRIPTTON 6.1 Engine Damage and Crew Action Descriptions 6.2 Probability of Damage 6.3 Crew Action and Engine Shutdown Probabilities 6.4 Engine Failur~s 7 PROBABILITY ESTIMATES 8 DATA QUALTTY 8.1 Data Sources 8.2 Internal Consistency 9 CONCLUSZONS 11 GLOSSARY APPENDICES A - Airports with Scheduled Boeing-737 Flights and/or Reported Bird Ingestion Events B - Contents of FAA Bird Ingestion Data Base Boeing-737 Airplane C - Statistical Hypothesis Testing 737 Aircraft Engine Bird Ingestion Study Data Summary xiii Histogram of Monthly Aircraft Operat ions by Engine Type 9 Contour Map of Domestic Aircraft Ingestion Events 11 IIistogram of Bird Ingestion Events by State 12 Histogram of Number of Birds lngested by Weight Class 18 Histogram of Monthly Wor.ldwide Aircraft Ingestion Events 20 Histogram of Seasonal Aircraft Ingestion Rates 2 1 Histogram of Aircraft Ingestion Events by Time of Day 2 2 Hist-ogram of Plontllly Aircraft Ingest ion Rates by Engine Type (Normalized for lrllet Area) 2 6 Comparison of Observed and Predicted CUFs for United States JT8D Aircraft Ingestion Events 3 1 Comparison of Observed and Predicted CUFs for Contiguous United States JT8D Aircraft lngestiorl Events 32 Cornparism of Observed and Predicted CDFs for Foreign JT8D Aircraft Irlgesti on Events 3 3 Comparison of Observed and Predicted CDFs for United States CFM56 Aircraft Ingestion Events 3 4 Comparison of Observed and Predicted CDFs for Contiguous United States CFM56 Aircraft I~lgestionEvents 3 5 Comparison of Observed and Predicted CDFs for Foreign CFM56 Aircraft Ingestion Events 3 6 Histogram of Aircraft Ingestion Events at Domestic Airports 50 Histogram of Aircraft Ingestion Events at Foreign Airports 52 Estimated POD Function for Any Damage with the 95 Percent Confidence Bound 7 4 Estimated POD F~mctionfor Moderate or Worse Damage with the 95 Percent Confidence Bound 7 4 Estimated POD Function for Severe Damage with the 95 Percent Conf idence Bound 7 4 LIST OF ILLUSTRATIONS (Continued) 8.1 Comparison of the United States Bird Weight Distributions 9 1 for the First, Second, and Third Years 8.2 Comparison of the Foreign Bird Weight Distributions for the First, Second, and Third YPR~S 92 vii LIST OF TABLES --Table 2.1 Scheduled OAG Airport Operations by Seasonal Month 2.2 Scheduled OAG Airport Operations by Season 2.3 OAG Airport Operations by Month 2.4 Scheduled Aircraft Operations by Engine Type 3.1 Tally of Positively Identified Bird Species Broken Down by US, Foreign, and Overall 3.2 Weight Distribution of Ingested Birds by Origin 3.3 Summary Statistics for Ingested Bird Weights 4.1A Breakdown of Bird Ingestion Rates by Engine and Location (Based on Aircraft Operations) 4.1B Breakdown of Bird Ingestion Rates by Engine and Location (Based on Engine Operations) 4.2A Ingestion Rates for Engine Type by Phase of Flight. (Based on Aircraft Ingestion Events) 4.2B Ingestion Rates for Engine Type by Phase of Flight (Based on Engine Ingestion Events) 4.3 Results of the Exponential GOF Tests to Verify the Poisson Process 5.1 Frequency Count of Aircraft Ingest ion Events by Airport and Phase of Flight 5 -2 Airport Bird Ingestion Rates 6.1 Definition of Engine Damage Categories 6.2 Types of Damage Caused by Bird Ingestions 6.3 Tally of Positively Indentified Bird Species by Weight 6.4A 737 Aircraft En~ineBird Ingestion Damage Summary (Total Bird Events) 6.4B 737 Aircraft Engine Bird Ingestion Damage Summary (Single Bird Events) 6.4C 737 Aircraft Engine Bird Ingestion Damage Summary (Multiple Bird Events) viii LIST OF TABLES (Continued) Table 6.5 Phase-of-Flight (,Pol?) Analysis 6.6 Aircraft Airspeed Analysis 6.7 Multiple Engine and Multiple Bird Analysis 6.8 Damage Severity Definitions 6.9 Conditional Probability of Crew Action Given The Engine Damage Severity 6.10 Engine Failure Summary by Bird Weight 7.1 Aircraft Operation Ingestion Probabilities 7.2 Aircraft Operation Ingestion Probabilities by Location and Engine Type 7.3A Probability of Ingestion as a Function of Bird Weight by Location and Engine Type (Based on Aircraft Operations) 7.3B Probability of Ingestion as a Function of Bird Weight by Location and Engine Type (Based on Engine Operations) 7.4A Probability of Ingestion as a Function of Bird Weight by Location (Based on Ai-rcraft Operations) 7.4B Probability of Ingestion as a Function of Bird Weight by Location (Based on Engine Operations) 8.1 Counts for United States and Foreign Aircraft Events and Aircraft Operations by Year and Engine 8.2 Chi-Squared Test Statistics for Comparing Annual Ingestion Rates 8.3 Comparison of Weight Distributions Between Birds Ingested in the First:, Second, and Third Years EXECUTIVE SUMMARY An investigation was initiated by the Federal Aviation Administration (FAA) Technical Center in September 1986 to determine the numbers, weights, and species of birds which are ingested into medium and large inlet area turbofan engines during worldwide service operation and to determine what damage, if any, results. This report summarizes the three years of Boeing-737 (B737) data that were collected by the engine manufacturers, the FAA, and the International Civil Aviation Organization (ICAO) as part of a separate data collection. This report includes the ICAO data in the statistical analysis. The previous report (report number DOTIFAAICT--90128[I]) was based only on the three years of data collected by the engine manufacturers and the FAA because only the first two years of ICAO data were available.