Military Jet Engine Acquisition
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Military Jet Engine Acquisition Technology Basics and Cost-Estimating Methodology Obaid Younossi, Mark V. Arena, Richard M. Moore Mark Lorell, Joanna Mason, John C. Graser Prepared for the United States Air Force Approved for Public Release; Distribution Unlimited R Project AIR FORCE The research reported here was sponsored by the United States Air Force under Contract F49642-01-C-0003. Further information may be obtained from the Strategic Planning Division, Directorate of Plans, Hq USAF. Library of Congress Cataloging-in-Publication Data Military jet engine acquisition : technology basics and cost-estimating methodology / Obaid Younossi ... [et al.]. p. cm. “MR-1596.” Includes bibliographical references. ISBN 0-8330-3282-8 (pbk.) 1. United States—Armed Forces—Procurement—Costs. 2. Airplanes— Motors—Costs. 3. Jet planes, Military—United States—Costs. 4. Jet engines— Costs. I. Younossi, Obaid. UG1123 .M54 2002 355.6'212'0973—dc21 2002014646 RAND is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND® is a registered trademark. RAND’s publications do not necessarily reflect the opinions or policies of its research sponsors. © Copyright 2002 RAND All rights reserved. No part of this book may be reproduced in any form by any electronic or mechanical means (including photocopying, recording, or information storage and retrieval) without permission in writing from RAND. Published 2002 by RAND 1700 Main Street, P.O. Box 2138, Santa Monica, CA 90407-2138 1200 South Hayes Street, Arlington, VA 22202-5050 201 North Craig Street, Suite 202, Pittsburgh, PA 15213-1516 RAND URL: http://www.rand.org/ To order RAND documents or to obtain additional information, contact Distribution Services: Telephone: (310) 451-7002; Fax: (310) 451-6915; Email: [email protected] PREFACE In recent years, the affordability of weapon systems has become increasingly important to policymakers in the Department of Defense and U.S. Congress. Aerospace industry analysts and some government officials have asserted that government cost estimates are based on outdated methods that do not account for the latest technological innovations. The authors of this report present the results of a RAND research study to update the methods for estimating military jet engine costs and development time. This report is one of a series from a RAND Project AIR FORCE re- search project called “The Cost of Future Military Aircraft: Historical Cost Estimating Relationships and Cost Reduction Initiatives.” The purpose of the project, which is part of the Resource Management Program, is to improve the tools available to the U.S. Air Force for estimating the cost of future weapon systems. The authors provide insights into military engine technology, the military aircraft acquisi- tion process, and parametric cost-estimating methodologies. This study draws from databases from various Air Force, Navy, and military engine contractors and interviews with government experts from the Air Force Research Laboratory (AFRL), Aeronautical Sys- tems Center/Engineering (ASC/EN), Naval Air Systems Command, and industry experts from General Electric, Pratt and Whitney, and Rolls-Royce (North America). This report should be of interest to the cost-analysis community, the military aircraft acquisition community, and acquisition policy pro- fessionals in general. iii iv Military Jet Engine Acquisition Lieutenant General Stephen B. Plummer, SAF/AQ, sponsored this project. The project’s technical point of contact is Jay Jordan, techni- cal director of the Air Force Cost Analysis Agency. Other RAND Project AIR FORCE reports that address military aircraft cost-estimating issues are: • Military Airframe Acquisition Costs: The Effects of Lean Manufac- turing by Cynthia R. Cook and John C. Graser (MR-1325-AF). In this report, the authors examine the package of new tools and techniques known as “lean production” to determine if it would enable aircraft manufacturers to produce new weapon systems at costs below those predicted by historical cost-estimating models. • An Overview of Acquisition Reform Cost Savings Estimates by Mark A. Lorell and John C. Graser (MR-1329-AF). For this report, the authors examined the relevant literature and conducted in- terviews to determine whether estimates on the efficacy of ac- quisition reform measures are sufficiently robust to be of predic- tive value. • Military Airframe Costs: The Effects of Advanced Materials and Manufacturing Processes by Obaid Younossi, Michael Kennedy, and John C. Graser (MR-1370-AF). In this report, the authors ex- amine cost-estimating methodologies and focus on military air- frame materials and manufacturing processes. This report pro- vides cost estimators with factors that are useful in adjusting and creating estimates that are based on parametric cost-estimating methods. PROJECT AIR FORCE Project AIR FORCE, a division of RAND, is the Air Force Federally Funded Research and Development Center (FFRDC) for studies and analyses. It provides the Air Force with independent analyses of pol- icy alternatives affecting the development, employment, combat readiness, and support of current and future aerospace forces. Re- search is performed in four programs: Aerospace Force Develop- ment; Manpower, Personnel, and Training; Resource Management; and Strategy and Doctrine. CONTENTS Preface ........................................ iii Figures ........................................ ix Tables......................................... xi Summary ..................................... xiii Acknowledgments............................... xvii Acronyms ..................................... xix Chapter One INTRODUCTION ..............................1 Study Background and Purpose ....................1 Updating of Previous Study Methods ................2 The Organization and Content of This Report .........2 Part I: Engine Basics and Performance Parameters Chapter Two JET ENGINE BASICS, METRICS, AND TECHNOLOGICAL TRENDS .....................................9 Jet Engine Basics ...............................9 Jet Engine Parameters ..........................14 Approaches to Jet Engine Development .............22 Summary ...................................23 Chapter Three TRENDS IN TECHNOLOGICAL INNOVATION ........25 Programs and Initiatives ........................25 Component and Related Technical Advancements .....28 v vi Military Jet Engine Acquisition Low Observables ............................28 Integrally Bladed Rotors .......................29 Alternatives to Engine Lubrication Systems: Air Bearings or Magnetic Bearings ................30 Thrust-Vectoring Nozzles for High-Performance Tactical Aircraft ...........................31 Fluidic Nozzles for Afterburning Thrust-Vectoring Engines .................................32 Integral Starter-Generators and Electric Actuators ...32 Prognostics and Engine Health Management .......33 Advanced Fuels .............................34 Cooled Cooling Air ...........................35 Advanced Materials ..........................35 Ceramics and Ceramic Matrix Composites .........36 Intermetallics ......................... 36 Summary ...................................37 Part II: Data Analysis and Cost-Estimating Techniques Chapter Four AN OVERVIEW OF COST-ESTIMATING METHODS ....41 Bottom-Up Method ...........................41 Estimating by Analogy ..........................42 Estimating by Parametric Method .................42 Summary ...................................45 Chapter Five ESTIMATING PARAMETERS AND GATHERING DATA ......................................47 Estimating Parameters .........................48 Performance and Physical Parameters ............48 Technical Risk and Design Maturity Parameters .....48 Additional Measures of Technical Risk and Maturity ................................52 Criteria for Including Parameters ................55 Data Gathering ...............................56 Extent of Data ..............................57 Data Verification Process ......................59 Chapter Six STATISTICAL ANALYSIS ........................63 Development Cost............................. 64 Contents vii Development Time ............................75 Production Cost ..............................76 Normalizing the Data ........................76 Production Cost CER .........................79 Applying the Results: A Notional Example ...........81 Summary ...................................84 Chapter Seven CONCLUSIONS............................... 85 Appendix A. AN EXAMINATION OF THE TIME OF ARRIVAL METRIC ....................................87 B. AN OVERVIEW OF MILITARY JET ENGINE HISTORY ...97 C. AIRCRAFT TURBINE ENGINE DEVELOPMENT ...... 121 D. MODERN TACTICAL JET ENGINES ............... 137 Bibliography ................................... 147 FIGURES 2.1. Pratt & Whitney F100-220 Afterburning Turbofan ...12 2.2. Turbojet and Turbofan Thrust-Specific Fuel Consumption Trends Since 1950 ...............16 2.3. Turbojet and Turbofan Thrust-to-Weight Trends Since 1950................................ 17 2.4. Turbojet and Turbofan Overall Pressure Ratio Trends Since 1950................................ 18 2.5. Materials and Heat Transfer Effects on a Film-Cooled Turbine Blade .............................20 2.6. Turbojet and Turbofan Rotor Inlet Temperature Trends Since 1950 ..........................21 3.1. Integrally Bladed Rotor (Blisk) .................29 5.1. State-of-the-Art Metric for Fan Engine Rotor Inlet Temperature ............................. 50 5.2.