The Fundamentals of Aircraft Combat Survivability Analysis and Design Second Edition Robert E. Ball, Ph.D. Distinguished Professor Emeritus Naval Postgraduate School Monterey, California EDUCATION SERIES Joseph A. Schetz Series Editor-in-Chief Virginia Polytechnic Institute and State University Blacksburg, Virginia dehsilbuP by naciremA Institute of scituanoreA dna Astronautics, .cnI 1081 Alexander Bell Reston, Drive, AV 4434-19102 American Institute of Aeronautics and Astronautics, Inc. 2345 Library of Cataloging-in-Publication Data Congress Ball, Robert E. The fundamentals of aircraft combat survivability analysis and design/ written by Robert E. Ball.--2nd ed. p. cm.--(AIAA education series) Includes bibliographical references and index. ISBN 1-56347-582-0 (Hardcover : alk. paper) .1 Airplanes, Military--United States---Combat survivability. .2 Airplanes, Military--United StatesmDesign and construction. .3 Air warfare. I. Title. II. Series. UG1243.B35 2003 623.7'46--dc21 2003010568 Copyright © 2003 by the American Institute of Aeronautics and Astronautics, Inc. Printed in the United States of America. No part of this publication may be reproduced, distributed, or transmitted, in any form or by any means, or stored in a database or retrieval system, without the prior written permission of the copyright owner. Data and information appearing in this book are for informational purposes only. AIAA is not responsible for any injury or damage resulting from use or reliance, nor does AIAA warrant that use or reliance will be free from privately owned rights. The U.S. Government has a copyright license in this work pursuant to a Cooperative Research and Development Agreement with NAVAL POSTGRADUATE SCHOOL. AIAA Education Series Editor-in-Chief Joseph A. Schetz ainigriV Institute Polytechnic and State University Editorial Board Takahira Aoki Brian Landrum University of oykoT University of Alabama, Huntsville Robert H. Bishop Robert G. Loewy University of saxeT at Austin Institute Georgia of ygolonhceT Aaron R. Byerley Achille Messac .S.U Air Force Academy Rensselaer Institute Polytechnic Richard Colgren Michael Mohaghegh Lockheed Martin Corporation ehT Boeing Company Kajal K. Gupta Todd J. Mosher NASA Dryden Flight Research University of hatU Center Albert D. Helfrick Dora E. Musielak Embry-Riddle Aeronautical Northrop Grumman Corporation ytisrevinU David K. Holger Conrad E Newberry Iowa State University Naval Postgraduate School Rakesh K. Kapania David K. Schmidt ainigriV Institute Polytechnic University of ,odaroloC and State University Colorado Springs David M. Van Wie Johns Hopkins University Foreword The second edition of the authoritative text The Fundamentals of Aircrafi Combat Survivability Analysis and Design by Dr. Robert E. Ball provides a wealth of new information for the design of combat aircraft. The first edition of this book was published in 1985 as the fourth book in the newly established AIAA Education Series of textbooks for which I served as its editor-in-chief for some 20 years. This unique text provided invaluable materials for the military planners and aerospace industry designers to improve the survivability of future U. S. military aircraft. The great testimony to this improvement in survivability of the new generation of combat aircraft is the superb combat performance of U. S. aircraft in the re- cent Operation Iraqi Freedom. Throughout his academic career Professor Ball has established himself unquestionably as the foremost authority on the subject. As a member of the Joint Technical Coordinating Group on Aircraft Survivability sponsored by the U. S. Department of Defense, he was able to incorporate the latest concepts into his revised text that will have an impact on the design of new military aircraft for the 12 st century. As in the first edition, the text is organized into chapters on )1 Introduction to the Aircraft Combat Survivability Discipline, 2) Aircraft Anatomy, 3) Missions, Threats, and Threat Effects, 4) Susceptibility (PH and PF), 5) Vulnerability HIKP( and PKIF), and 6) Survivability (Ps and PK). Appendix A provides survivability features of several aircraft used in World War II and Appendix B summarizes probability theory and its application to survivability assessment. Also a useful list of acronyms is provided. Thus the new edition, like the old one, will continue to be the world's leading source of information for the design of survivable combat aircraft. It shoulbde noted that the AIAA Education Series of textbooks and monographs, inaugurated in 1984, embraces a broad spectrum of theory and application of not only different disciplines in aeronautics and astronautics, including aerospace de- sign practice, but also texts, such as the present one, on defense science, engineer- ing, and management. J. S. Przemieniecki Former Editor-in-Chief AIAA Education Series vii Foreword to the Previous Edition ehT Fundamentals of Survivability Aircraft Combat Analysis and Design by Robert E. Ball--a comprehensive treatise on survivability concepts in the design of mili- tary aircraft--presents the fundamentals of the newly emerging design discipline of survivability engineering applied to tactical and strategic aircraft: both theoretical background for this new discipline and, just as important, lessons of survivability from the past military operations with various types of aircraft, both fixed- and rotary-wing. Professor Ball developed this text from lecture notes prepared for a survivability course at the U. S. Naval Postgraduate School; he also used his notes in a similar course at the Air Force Institute of Technology. Both courses provided Dept. of Defense engineers and technical managers with the opportunity to learn the fundamentals of survivability engineering and their application in aircraft design. Publication of ehT Fundamentals of Aircraft Combat Survivability Analysis and Design, as a formal text in the AIAA Education Series, will allow for much broader dissemination of this important material to scientists and engineers in the aerospace industry concerned with survivability of the next generation of military aircraft. Likewise, the text should also be of a great value to military analysts who plan combat operations with the objective of maximizing the survivability of the aircraft. J. S. Przemieniecki Editor-in-Chief AIAA Education Series 1985 ix Preface The concept of designing and operating military aircraft to survive in combat orig- inated early in the 20th century when the pilots of World War I aircraft flew above the maximum altitude of the enemy's ground-based guns, sat on stove lids for addi- tional protection, and carried guns to defend themselves from the enemy fighters. However, it was not until the early 1970s, as the conflict in Southeast Asia (SEA) drew to a close, that combat survivability began to emerge as a formal design discipline for military aircraft. In 1985 AIAA (http://www.aiaa.org) published the first survivability textbook entitled The Fundamentals of Aircraft Combat Surviv- ability Analysis and Design as part of their new Education Series. I was the author. That textbook presents the fundamentals of the aircraft combat survivability design discipline as I understood them in 1985. It provides the reader with the history, concepts, terminology, facts, procedures, requirements, measures, methodology, and the technology for the nonnuclear combat survivability analysis and design of both fixed-wing and rotary-wing aircraft. It is also applicable to unmanned aerial vehicles (UAVs) and guided/cruise missiles. Approximately 10,000 copies of the first edition have been sold in five printings. Why this second edition of the textbook? There are many reasons, and some of them are given in the following paragraphs. What Has Happened to Survivability Since 1985? The aircraft combat survivability discipline has come a long way since the first textbook was published in 1985. It is now an established design discipline for U. S. military aircraft. New 'stealth' aircraft have been developed with survivability as one of the highest design priorities. The public appearance of the U. S. Air Force F-117 fighter and B-2 bomber in 1988 brought out of the black perhaps the most significant design revolution since the development of the jet engine in WWII. The latest aircraft in development or production today, such as the F/A-18E/F, F/A-22, V-22, RAH-66, and Joint Strike Fighter (JSF), are designed to survive while operating in their projected threat environment. Designing U. .S aircraft for survivability during the 1970s and 1980s paid off in Operation Desert Storm in 1991 when survivability played a major role in the success of the U. S. air operations. According to the data,* Air Force F-117s conducted nearly 1800 strikes at night (defined in the Gulf War Air Power Sur- vey as the delivery of a weapon or weapons against a specific target) and were credited with destroying a significant percentage of the strategic targets attacked by the coalition forces without a single loss or damage incident as a result of the * Gulf War Air Power Survey, Vol. ,V A Statistical Compendium and Chronology, U. .S Government Printing Office, Washington, DC, 1993, xix xx PREFACE combination of stealth, electronic attack, and the darkness of night. The A-10, designed in the early 1970s to survive the extremely hostile close air support mis- sion, conducted over 6800 strikes in Desert Storm. Approximately one-half of these strikes were against military troop installations, material and storage depots, and fortifications and defense systems. Although 20 A-10/OA-10s were hit while on daytime combat or combat support missions, 41 of the 20 survived because of the aircraft's rugged design, and the six aircraft that were killed were downed by infrared (IR) surface-to-air missiles (SAMs). Three other A-10s survived similar IR missile hits. According to Air Force Capt. Paul Johnson, who flew home from a mission over Kuwait with a gaping hole in his A-10's fight wing, "The guys developed a great affection for the airplane and a very healthy respect for what it could absorb?'* Other aircraft developed since the end of the SEA conflict, such as the UH-60 and AH-64 helicopters and the F-15, F-16, and F/A-18, relied heavily on their survivability features as they operated in one of the world's most hostile air defense environments. Particularly noteworthy was the survival of the seven F/A-18s and two F-16s originally thought to be hit by IR SAMs. The accomplishments of these survivable aircraft were unprecedented in the annals of air warfare. According to Les Aspin, former U. S. Secretary of Defense, and U. S. Congressman William Dickinson, "The second key component of the air campaign enhanced by high technology is aircraft survivability. The remarkable survivability record in Operation Desert Storm allowed consistently high sortie rates, which in turn allowed the devastating momentum of the campaign to build. ''t The hostile environment military aircraft must operate in has changed since 1985. The continued improvement of antiaircraft weapons was to be expected. What was not expected in 1985 was the large array of weapons that are now available to any country--large or small; friend, neutral, or foe. The threats to U. S. military aircraft today are not just the "red" threats developed by the former Soviet Union, but now include French, Chinese, British, and U. S. weapons, as well as weapons from many other smaller countries, such as Israel, Sweden, and South Africa. "Rainbow" weapons, which are weapons built by one country and modified by another country, are another proliferating threat. Of particular concern are the relatively inexpensive and potentially lethal man-portable air defense systems (MANPADS). In addition to the traditional threat posed by guns and guided missiles, anti- aircraft weapons that use directed electromagnetic energy to temporarily blind, permanently damage, or physically destroy critical aircraft sensors have been de- veloped. Accompanying these relatively new, but conventional, radiation threats are the unconventional chemical, biological, and nuclear weapons that were not perceived as realistic threats in the past but have now become threats that cannot be ignored. The concern for personnel safety and survivability has significantly increased in the U. S. military during the past two decades. According to the U. S. Navy Guiding riA"* ecroF toliP stseT s'01-A ssenhguoT ni ",elttaB Aviation Week and Space Technology, 5 .guA .1991 ,nipsAt ,.L dna ,nosnikciD ,.W Defense for a New Era, s'yessarB .U( ,).S ,.cnI ,notgnihsaW ,CD ,2991 .p .81 PREFACE xxi Principles presented in the 1992 Navy Policy Book, "The purpose of the Depart- ment of the Navy support establishment is to provide our sailors and Marines with the ability to go anywhere, anytime, to defend the nation's interests successfully and survive." (http://www.chinfo.navy.mil/navpalib/policy/navpolbk/navpolbk. txt) One example of this concern is the raid, known as Diablo Canyon, by Navy and Air Force aircraft on Libya in April 1986. The force package and tactics for the raid were designed to minimize losses. The military did not want a repeat of the incident in Lebanon in December 1983, when U. S. citizens watched on television as a downed U. S. pilot was dragged through the streets by an angry crowd. Con- sequently, a relatively large number of aircraft were dedicated to enhancing the survivability of the strike aircraft, serving as fighter escorts, antiradiation missile shooters, and electronic warfare aircraft. Nevertheless, one F-111 was lost, and not all of the mission objectives were achieved. The importance of survivability in combat has become so dominant that the Air Force general in charge of the Tactical Air Command in 1992 said that the B-2 bomber will not be used where the probability of survival is not virtually 100%. A retired vice admiral who once was the Deputy Chief of Naval Operations for Air Warfare wrote in the Naval Institute Proceedings in 1994,* "Unless the U. S. cartier force can conduct precision strikes with a high level of assurance of no losses, naval aviation could be drifting into ineffectiveness in the significant first- strike mission." A recent example of the U. S. military's desire to not lose aircraft in combat was their decision to not send AH-64 attack helicopters into combat in Kosovo during Operation Allied Force in the spring of 1999. One of the most important changes since the appearance of the 1985 textbook is the fact that survivability is now an essential part of the U. S. Department of Defense (DoD) acquisition process. In 1991 the DoD 5000 Series of Directives and Instructions for the acquisition of weapon systems defined survivability as a critical system characteristic, that is, a characteristic of the system that has a criti- cal role in the effectiveness of the system. According to the 2001 version of DoD Regulation 5000.2-R, "Mandatory Procedures for Major Defense Acquisition Pro- grams (MDAPS) and Major Automated Information System (MAIS) Acquisition Programs," C5.2.3.5.12 Survivability. Unless waived by the MDA (Major Decision Authority), mission-critical systems, including crew, regardless of the ACAT (Acquisition Category), shall be survivable to the threat levels anticipated in their projected operating environment as portrayed in the System Threat Assessment Report. Design and testing shall ensure that the system and crew can withstand man-made hostile environments without the crew suffering acute chronic illness, disability, or death. C5.2.3.5.12.1 The PM (Program Manager) shall fully assess system and crew survivability against all anticipated threats at all levels of conflict, early in the program, but in no case later than entering system demonstration or equivalent. This assessment shall also consider fratricide and detection. Another example of the recent integration of survivability into the acquisi- tion process is the Live Fire Test (LFT) law. This law was passed in fiscal year .ceD* ,4991 .p .82 xxii PREFACE 1987, when the U. S. Congress amended Title ,01 U. .S Code, by adding Sec- tion 2366, "Major Systems and Munitions Programs: Survivability and Lethal- ity Testing; Operational Testing." The LFT law requires that the Secretary of Defense conduct realistic survivability, lethality, and initial operational testing and evaluation (lOT&E) on covered weapons systems before they proceed be- yond low rate initial production. This program is currently under the direction of the Deputy Director, Operational Test and Evaluation~ive Fire Test and Evalua- tion. (http://www.dote.osd.milllfte/INDEX.HTML). Realistic survivability testing (referred to as full-up, system-level testing) means testing for the vulnerability of the system in combat by firing munitions likely to be encountered in combat (or munitions with a capability similar to such munitions) at the system config- ured for combat, with the primary emphasis on testing vulnerability with respect to potential user casualties and taking into equal consideration the operational require- ments and combat performance of the system. Configured for combat means load- ing or equipping the system with all dangerous materials (including all flammables and explosives) that would normally be onboard. The Secretary of Defense can waive the full-up, system-level tests if the Secre- tary certifies to Congress, before the system enters full-scale development, that such testing would be unreasonably expensive and impractical. An alternate program for evaluating the vulnerability of the system must accompany the waiver request. A study of the LFT law by the National Research Council's Committee on Weapons Effects on Airborne Systems came to the conclusion that "the law is a valuable contribution to vulnerability assessment and to the design of survivable aircraft."* The emphasis by the U. S. Department of Defense on aircraft survivability is revealed in several recent major weapons acquisition programs. The DoD, when announcing the winning team for the RAH-66 Comanche Lightweight Helicopter (LH) program, stated, "The LH is a fully integrated combat system designed for world-wide combat effectiveness. It will be lethal, survivable, and deployable, yet maintainable in a field environment." From a recent Operational Require- ments Document for an upgrade to an existing aircraft: "The following shortfalls severely limit mission accomplishment: inadequate payload, range, speed, and survivability." The F-22 Raptor candidate for the new U. S. Air Force advanced tactical fighter (ATF) had the motto, 'First look, first shot, first kill.' The most recent example of the importance of survivability to U. S. military aircraft is the Joint Strike Fighter program, now the F-35. The four 'pillars' of the JSF program are affordability, lethality, supportability, and survivability. The U. S. is not the only country that now considers survivability to be a crit- ical attribute of combat aircraft. The U. K. Ministry of Defence refers to system requirements as either cardinal points or key characteristics. The cardinal points are the essential attributes required of the system; the key characteristics are very important but not mandatory. The cardinal points identified for an attack helicopter include lethality, survivability, payload/range, mission management, night/adverse weather battlefield operations, and supportability. Key characteristics include eettimmoC* no snopaeW stceffE no emobriA ,smetsyS ytilibarenluV tnemssessA of ,tfarcriA A weiveR of ehT tnemtrapeD of esnefeD Live eriF tseT dna noitaulavE ,margorP lanoitaN hcraeseR ,licnuoC lanoitaN seimedacA ,sserP ,notgnihsaW ,CD .3991 PREFACE xxiii deployability (air/sea), manpower and personnel integration (MANPRINT), growth capability and interoperability.* As a consequence of this increased emphasis by the military on survivability in combat, the American Defense Preparedness Association (ADPA), now part of the National Defense Industrial Association (NDIA), established the Combat Sur- vivability Division in 1988 (http://www. ndia.org/committees/combat/index.cfm); and in 1989 AIAA added survivability to its list of technical committees (http://www. aiaa.org/tc/sur). Companies that compete for the award of a new aircraft development program, or seek approval to go into full-rate production, or are looking for foreign sales routinely run full-page ads in Aviation Week and Space Technology proclaiming the survivability of their product. The military is not the only community that has recently emphasized survivabil- ity. The attitude in the U. S. with regard to public health, safety, and survivability has changed over the past few decades, and society's tolerance for careless loss of life and property has diminished significantly. Government organizations have taken the lead in establishing requirements, and industry has jumped on the band- wagon. How many cities had 'no smoking' ordinances in 1985, and how many television commercials for automobiles in 1985 emphasized airbags and promoted the ability of their product to withstand a crash? Automobile seat belts, car seats for children, and motorcycle and bicycle helmets are the law now. Improving commercial aviation safety has become a major goal of the Federal Aviation Administration as the number of passengers escalates exponentially each year. According to an article in the 4 November, 1996 issue of Aviation Week and Space Technology entitled "Aviation Safety Takes Center Stage Worldwide," there were 21 aircraft accidents by U. S. major scheduled airlines that resulted in one or more fatalities in 3.8 million departures in 1960. This equates to one fatal accident per 317,000 departures or to 0.316 fatal accidents per 100,000 departures. In the 1990s the fatal accident rate fell to less than 0.01 per 100,000 departures as the number of flights nearly tripled. Although this significantly reduced rate appears to be very low, there could be a major hull loss once a week in the year 2015 if the increase in passenger traffic continues to grow at the historical rate and the accident rate remains constant. In addition to the normal hazards that accompany day-to-day flying in a world generally at peace, the air transport safety and security community must now contend with an increasing terrorist threat in the form of MANPADS that can be launched at an aircraft as it takes off or lands and explosives that are surreptitiously placed onboard an aircraft. Inspection equipment that can quickly detect explosive devices in passenger baggage is being developed, and baggage containers and aircraft cargo bay structures are being designed to withstand internal bomb blasts. A major experimental program using retired large-body aircraft is being conducted jointly by British and U. S. aviation security specialists to determine the ability of new hardening concepts to prevent catastrophic structural failure. Many of the physical phenomena associated with terrorist weapons are the same as those associated with military antiaircraft weapons, and many of the safety problems associated with mechanical failures and other hazards in peacetime, such as the ,sehguH* ,.D ",weivretnI" ecnefeD ,retpocileH yluJ-enuJ ,3991 .p .3