Wire Strike Devices Installed on Civil and Military Helicopters
Total Page:16
File Type:pdf, Size:1020Kb
DOT/FAA/AR-08/25 Safety Study of Wire Strike Air Traffic Organization Operations Planning Devices Installed on Civil and Office of Aviation Research and Development Military Helicopters Washington, DC 20591 September 2008 Final Report This document is available to the U.S. public through the National Technical Information Service (NTIS), Springfield, Virginia 22161. U.S. Department of Transportation Federal Aviation Administration NOTICE This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The United States Government assumes no liability for the contents or use thereof. The United States Government does not endorse products or manufacturers. Trade or manufacturer’s names appear herein solely because they are considered essential to the objective of this report. This document does not constitute FAA certification policy. Consult your local FAA aircraft certification office as to its use. This report is available at the Federal Aviation Administration William J. Hughes Technical Center’s Full-Text Technical Reports page: actlibrary.tc.faa.gov in Adobe Acrobat portable document format (PDF). Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient's Catalog No. DOT/FAA/AR-08/25 4. Title and Subtitle 5. Report Date SAFETY STUDY OF WIRE STRIKE DEVICES INSTALLED ON CIVIL AND September 2008 MILITARY HELICOPTERS 6. Performing Organization Code 7. Author(s) 8. Performing Organization Report No. Vengalattore T Nagaraj and Inderjit Chopra 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) Alfred Gessow Rotorcraft Center Dept. of Aerospace Engineering University of Maryland College Park, MD 20742 11. Contract or Grant No. 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered Department of Transportation Final Report Federal Aviation Administration Air Traffic Organization Operations Planning Office of Aviation Research and Development 14. Sponsoring Agency Code ASW-112 15. Supplementary Notes The Federal Aviation Administration Airport and Aircraft Safety R&D Division Technical Monitor was Dy Le. 16. Abstract Wire strike accidents involving United States military and civil helicopters for the period 1994-2004 were analyzed using military and the National Transportation Safety Board databases. The objective of the research was to conduct a study on wire strike accidents of civil and military helicopters between 1994 and 2004 to establish trends, assess the potential of existing technology for reducing wire strike accidents, and to recommend solutions that could substantially reduce the number of wire strike accidents. Trends in accidents were established for both military and civil wire strike accidents. The age group and experience profiles of the pilots involved in civil helicopter wire strike accidents were found to be similar to those found in an earlier study. Devices available for warning pilots about the proximity of wires are described and their relative merits assessed. Recommendations are made for reducing the number of helicopter wire strike accidents. 17. Key Words 18. Distribution Statement Helicopter accidents, Wire strike, Cable strike, Object This document is available to the U.S. public through the warning devices National Technical Information Service (NTIS), Springfield, Virginia 22161. 19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price Unclassified Unclassified 151 Form DOT F 1700.7 (8-72) Reproduction of completed page authorized TABLE OF CONTENTS Page EXECUTIVE SUMMARY ix 1. INTRODUCTION 1 1.1 Purpose 1 1.2 Background 1 1.3 Related Activities and Documents 2 2. DISCUSSION 3 3. EVALUATION APPROACH 7 3.1 Military Helicopter Wire Strike Accidents 7 3.1.1 Analysis Methodology 7 3.1.2 Analysis of Accidents 8 3.1.3 Narrative Description of Wire Strike Accidents From 2002-2003 10 3.1.4 Analysis of Wire Strike Protection System Use in U.S. Army Helicopters 12 3.1.5 Summary of Military Helicopter Wire Strike Accidents 14 3.2 Civil Helicopter Wire Strike Accidents 14 3.2.1 Data Sources and Methodology 14 3.2.2 Civil Helicopter Accident Rates 16 3.3 Wire Strike Accidents Involving U.S. Civil Helicopters 20 3.3.1 Overview of Wire Strike Accident Data 20 3.3.2 Wire Strike Statistics by Type of Operation 22 3.3.3 Wire Strike Statistics by Type of Helicopter 24 3.3.4 Wire Strike Accidents by Probable Cause 27 3.3.5 Analysis of Fatal Wire Strike Accidents 28 3.3.6 Summary of Civil Helicopter Wire Strike Incidents 30 3.4 Wire Strike Protection and Warning Systems 32 iii 3.4.1 Wire Strike Protection System 32 3.4.2 Powerline Detector 34 3.4.3 The OASys Radar 35 3.4.4 Laser Obstacle Awareness System 36 3.4.5 Laser Radar Visual Display 37 3.4.6 Ground Proximity Warning System 39 3.4.7 Passive Tower-Based System 39 3.4.8 Aerial Markers 40 3.4.9 Summary of the Systems 42 4. SUMMARY 42 4.1 Wire Strike Protection System 42 4.2 Powerline Detector 43 4.3 Helicopter-Installed Radar and Laser-Based Systems 43 4.4 Honeywell EGPWS 43 4.5 Aerial Markers 43 4.6 Obstacle Collision Avoidance System 44 4.7 Human Factors/Pilot Training 44 4.8 Recommendations 45 5. REFERENCES 45 APPENDICES A—U.S. Army Helicopter Accidents B—U.S. Civil Helicopter Wire Strike Accidents C—Extracts From Marking of Wires and Towers Recommendations iv LIST OF FIGURES Figure Page 1 Total Number of U.S. Army Helicopter Accidents and Fatalities (1994-2004) 9 2 U.S. Army Helicopter Wire Strike Accidents and Fatalities 9 3 U.S. Army Helicopter Wire Strike Accidents as Percentage of Total Accidents 10 4 Yearly Costs of U.S. Army Helicopter Wire Strike Accidents 10 5 U.S. Army Wire Strike Accidents 1980-2003 13 6 U.S. Army Wire Strike Accidents, Class A-C 13 7 U.S. Civil Helicopter Accidents: Number of Accidents and Number of Fatalities per Year 17 8 U.S. Civil Helicopter Accidents: Trend of Number of Accidents, Number of Fatalities, and Number of Fatal Accidents per 100,000 Flight Hours 17 9 Accident Rates, 1994 Through 2003, for U.S. Air Carriers Operating Under 14 CFR 121 18 10 U.S. Civil Helicopter Accident Rates by Engine Type 19 11 U.S. Civil Helicopter Accidents: Fatal Accidents/100,000 Flight Hours by Engine Type 19 12 U.S. Civil Helicopter Accidents: Fatalities/100,000 Flight Hours by Engine Type 20 13 U.S. Civil Helicopter Accidents by Type of Operation 20 14 Comparison of Yearly U.S. Civil Helicopter Wire Strike Accidents Obtained in Three Different Studies 22 15 Civil Helicopter Wire Strike Accidents by Type of Operation for 1994-2003 24 16 U.S. Civil Helicopter Wire Strike Accidents by Type of Operation 24 17 Helicopter Wire Strike Accidents by Model 26 18 Wire Strike Accidents Involving Bell 206 26 19 Wire Strike Accidents Involving Bell 47 27 v 20 Wire Strike Accidents Involving Robinson R22 27 21 U.S. Civil Helicopter Fatal Accidents by Operation (1994-2003) 29 22 Comparison of Accidents and Fatalities by Type of Operation (1994-2003) 29 23 The WSPS Installed on a Bell 206 32 24 Maximum Wire Strike Angle 33 25 Powerline Detector Electronics Control 34 26 Zones of Scan, OASys 35 27 Zone of Scan at 100 Knots, OASys 35 28 The OASys Scan Head 36 29 The LOAS Scan Head and Electronics 37 30 HELLAS Installed on UH-60 Helicopter 38 31 SpanGUARD Installation 41 vi LIST OF TABLES Table Page 1 U.S. Army Accidents (Class A-D) 8 2 U.S. Civil Helicopter Accident Statistics All Accidents 16 3 U.S. Civil Helicopter Wire Strike Accidents 21 4 Comparison of Wire Strike Statistics for Two Decades 21 5 U.S. Civil Helicopter Wire Strike Accidents by Type of Operation 22 6 U.S. Civil Helicopter Wire Strike Accidents as Percentage of Wire Strikes 23 7 Comparison of Wire Strike Accidents by Type of Operation (1970-1979 and 1994-2003) 23 8 Helicopters Involved in Wire Strikes 25 9 Age Profile of Pilots Involved in Fatal Wire Strike Accidents During 1994-2003 28 10 Helicopter Flight Experience of Pilots Involved in Fatal Wire Strike Accidents During 1994 28 11 Helicopters Involved in Fatal Wire Strike Accidents 30 12 Price of WSPS for Helicopter Models 33 13 SpanGUARD Helimark Specifications 41 14 Summary of Wire Protection and Detection Devices 42 vii LIST OF ACRONYMS AGL Above ground level CFR Code of Federal Regulations EADS European Aeronautics and Space Company EGPWS Enhanced Ground Proximity Warning System FAA Federal Aviation Administration GPS Global positioning system HAI Helicopter Association International HELLAS Dornier’s Helicopter Laser Radar IFR Instrument flight rules IKAR International Commission for Alpine Rescue LOAS Laser Obstacle Awareness System MD McDonnell Douglas MOWAT Marking of Wires and Towers NTSB National Transportation Safety Board OASys Obstacle Awareness System OCAS Obstacle Collision Avoidance System PTS Practical Test Standards UHF Ultra high frequency U.S. United States Vac Volts alternating current Vdc Volts direct current VFR Visual flight rules VHF Very high frequency WSPS Wire strike protection system viii EXECUTIVE SUMMARY Wire strike accidents involving United States military and civil helicopters for the period 1994- 2004 were analyzed using military and the National Transportation Safety Board safety databases. The objective of the research was to conduct a study on wire strike accidents of civil and military helicopters between 1994 and 2004 to establish trends, assess the potential of existing technology for reducing wire strike accidents, and to recommend solutions that could substantially reduce the number of wire strike accidents. Trends in accidents were established for both military and civil wire strike accidents.