N O T I C E THIS DOCUMENT HAS BEEN REPRODUCED FROM MICROFICHE. ALTHOUGH IT IS RECOGNIZED THAT CERTAIN PORTIONS ARE ILLEGIBLE, IT IS BEING RELEASED IN THE INTEREST OF MAKING AVAILABLE AS MUCH INFORMATION AS POSSIBLE S NASA CR-135192 EDR 9132 • STUDY OF TURBOPROP SYSTEMS RELIABILITY AND MAINTENANCE COSTS (NASA-CR - 135192) STUDY OF TURBOPROP SYSTEMS N80-14129 RELIABILITY AND MAINTENANCE CCSTS Final Report (Detroit Diesel Allison, Indianapolis, Ind.) 304 p HC A14/MF A01 Unclas CSCL 21E G3/07 46483 JUNE 1978 I Detroit Diesel Allison Division of General Motors Corporation t40:k) ^: c f, •fl. prepared for NATIONAL AERONAUTICS AND SPACE ADMINISTRATION NASA Lewis Research Center Contract NAS 3-20057 n~ 6ti' TABLE OF CONTENTS SECTION DESCRIPTION PAGE 1.0 SUMMARY 1 2.0 INTRODUCTION 4 3.0 TASK I - COLLECTION, PREPARATION, AND ANALYSIS 5 OF ACTUAL TURBOPROP PROPULSION RELIABILITY AND MAINTENANCE COSTS 3.1 Selection of Turboprop Propulsion System for 5 Analysis 3.2 Data Sources 3.2.1 DDA Reliability Department Records it 3.2.2 CAB Form 41 Data 27 3.2.3 Airline Data 29 3.2.4 Repair Facilities 39 3.3 Baseline Turboprop Propulsion System Mainten- 46 ance Cost 3.3.1 Engine, Reduction Gearbox, QEC 46 3.3.2 Propeller 54 3.3.3 Total 501-D13/54H60 Turboprop 73 Propulsion System 3.4 Comparison With Turbofan Maintenance Costs 75 3.4.1 JTBD Direct Maintenance Costs 75 3.4.2 Maintenance Cost of Turboprop System 81 Scaled to JT8D Thrust Size 3.4.3 Comparative Maintenance Costs of 84 6 501-D13/54H60 and JTBD 3.4.4 High Bypass Turbofan Maintenance Costs 86 4 1 .'I 0 TABLE OF CONTENTS (cont.) SECTION DESCRIPTION PAGE 3.5 Reliability and Maintenance Cost !.ialysis 89 3.5.1 Maintenance Cost Analysers 89 3.5.2 Reliability Analysis 94 3.5.3 Recommendations for Future Systems 106 4.0 TASK Il - FUTURE TURBOPROP SYSTEMS 109 4.1 Design, Reliability, and Maintainability 109 Re. .irements 4.1.1 Reliability and Life Goals 110 4.1.2 Maintenance Philosophy 113 4.1.3 Design Requirements 114 4.1.4 Design Requirements Document 119 4.2 Ratings for Advanced Turboprop System 120 4.3 Design Description of Future System 123 4.3.1 Propulsion System Arrangement 123 4.3.2 Advanced Propeller (Prop-Fan) 129 4.3.3 Main Drive Reduction Gearbox 148 4.3.4 Power Section 169 4.3.5 Control and Fuel System 176 4.3.6 Lubrication System 186 4.3.7 Power Section Accessory Drive Assembly 187 4.3.•8 Maintainability Features 189 4.3.9 Reliability Assessment 203 ii W TABLE OF CONTENTS (cont.) SECTION DESCRIPTION PAGE 4.4 Maintenance Cost Projection of Future System 229 4.4.1 Advanced Turboprop Comparison with an Advanced 235 Turbofan 4.4.2 Direct'Operating Cost (DOC) Sensitivity to Propulsion System Maintenance Costs 238 4.4.3 Quantification of Benefits 240 5.0 CONCLUSIONS, AND RECOM1ENDATIONS FOR FUTURE TECHNOLOGY DEVELOPMENT 246 5.1 Conclusions 246 5.2 Recommendations for Future Technology Development 249 5.2.1 Advanced Propeller (Prop-Fan) Blade 249 5.2.2 Main Drive Reduction Gearbox 252 5.2.3 Advanced Turboprop Design Definition Study 253 6.0 Airline Reviews and Comments 2S7 6.1 United Airlines 2S7 6.2 Frontier Airlines 257 Appendix A 261 References 292 Distribution List 294 E iii LIST OF ILLUSTRATIONS FIGURE TITLE PAGE 3.1-1 Detroit-Diesel Allison Model S01-D13 turboprop . engine 7 3.1-2 Diagrammatic Assembly of Aeroproducts 606 propeller 8 3.1-3 Diagramatic assembly of Hamilton Standard S4H60 propeller 9 3.2.1-1 Reliability Department Recors - L188 Electra CVS80 airplanes 12 3.2.1-2 Reliability Department Recors--Convair CVS80 airplane 14 3.2.1.1-1 606A propeller removal rates, CV580 aircraft, scheduled airlines 25 3.2.1.1-2 606 propeller removal rate, Electra aircraft 26 3.2.2-1 QEC removal from P3V 28 3.2.3.3.2-1 Summary Eastern Airlines Electra 606 propeller and regulator removal rate 40 3.3.1-•1 Direct Cost per engine flight hour - 501-D13 engine and gearbox 47 3.3.1-2 Direct maintenance cost breakdown - S01-D13 engines/Electra airplanes SO 3.3.1-3 Direct maintenance cost breakdown - S01-D13 engines/Convair airplanes 51 3.3.1-4 Engine flight hours - S01-D13 engines and gear- boxes 52 3.3.1-S Direct, fully burdened, and unburdened mature maintenance costs SS 3.3.2.1-1 Summary of 606 propeller system maintenance cost data 59 3.3.2.1-2 Summary of 606 propeller reliability data 62 3.3.2.3-1 Comparison of Aeroproducts 606 and Hamilton Standard 54H60 propeller shop maintenance costs 70 3.3.2.3-2 Sources of difference in Aeroproducts 606 and Hamilton Standard 54H60 propeller shop maintenance cost 70 3.3.3-1 Mature direct, burdened, and unburdened cost per flight hour of the 501-D13/54H60 turboprop systems 3.4.1-1 Engine flight hours - JT8D-1 and -7 engines 77 3.4.1-2 Direct cost per engine flight hour - JT8D-1 and -7 engines 78 3.4.3-1 Comparison of turboprop and JT8D maintenance costs per engine flight hr 85 3.4.4-1 Direct maintenance cost per engine flight hour for JT9D, CF6-6, and RB211 engines 87 3.4.4.2 Comparison of JT8D-7 and JT9D-7 engine direct maintenance costs per lb thrust 88 3.5.1.1-1 Breakdown of shop maintenance costs, 501-D13 engine and gearbox 91 v PUCOM PAGE BLANK NOT FiLN1EE1 FIGURE TITLE PAGE 3.5.1.2-1 Breakdown of shop maintenance costs, S4H60 propeller 93 3.5.1.3-1 Turboprop and non-turboprop functions compared to JTBD maintenance costs 9S 3.5.2-1 Contribution of each major module to the total major module premature removal rate during CY 1965-1968 102 4.1.2-1 Advanced turboprop propulsion system aircraft nacelle concept 115 4.1.2-2 Advanced turboprop propulsion system propeller removal concept 116 4.1.2-3 Advanced turboprop propulsion system advanced propeller and main drive reduction gearbox removal concept 117 4.1.2-4 Advanced turboprop propulsion system power section removal concept 118 4.3.1-1 Advanced turboprop propulsion system general arrangement 124 4.3.1-2 Advanced turboprop propulsion system less installation parts 127 4.3.2.1-1 Prop-fan modular design 130 4.3.2.1-2 Prop-fan concept 131 4.3.2.1-1-1 Prop-fan blade concept 133 4.3.2.1-1-2 Blade heater 134 4.3.2.1.5-1 Pitch change regulator schematic 137 4.3.2.2-1 Pitch change actuator 141 4.3.3.1-1 Basic offset planetary gearbox powertrain 149 4.3.3.1-2 Basic dual compound idler gearbox powertrain 150 4.3.3.1-3 Offset planetary powertrain with high life bearings 151 4.3.3.2-1 Rear view of compound idler reduction gearbox 1S3 4.3.3.4-1 Idler equal load sharing design 159 4.3.3.5.1-1 Accessorized propeller brake 161 4.3.3.6-1 501-D13 reduction gearbox accessory drive train 164 4.3.3.6-2 Advanced reduction gearbox accessory drive train 165 4.3.5.2-1 Advanced turboprop propulsion system control block design 179 4.3.5.3-1 Preliminary logic diagram for advanced turboprop propulsion system control 182 4.3.S.S-1 Advanced turboprop propulsion system control interface diagram 185 4.3.8-1 Advanced turboprop propulsion system modular assembly 195 vi R FIGURE TITLE PAGE 4.3.9.4.1-1 Determination of main drive reductiongear bearing set reliability at 7000 hr from average life points 218 4.3.9.4.1-2 Extension of cumulative removal rate at 7000 hr to 35,000 hr 219 4.3.9.7-1 Projected total propulsion system equipment operational reliability for advanced turboprop 227 4.3.9.7-2 Projected major module operational reliability for advanced turboprop 228 4.4-1 Advanced turboprop maintenance cost projection 234 4.4.1-1 Variation of estimated advanced turbofan maintenance costs with engine price 236 4.4.1-2 Advanced turboprop and advanced turbofan maintenance cost comparison 237 4.4.2-1 DOC sensitivity to prop-fan maintenance cost 239 4.4.3.1-1 Maintenance reduction sources for prop fan 241 4.4.3.2-1 Maintenance cost reduction sources for advanced reduction gearbox 243 4.4.3.3-1 Maintenance cost reduction sources for and comparison with advanced core 24S 5.2.1-1 Comparison of HS prop-fan blade with HS current design 250 1.0-1 Propulsion system modular breakdown 264 1.0-2 Propulsion system general arrangement 26S 2.4-1 Propulsion system load envelopes 267 3.2-1 Advanced turboprop duty cycle 271 vii LIST OF TABLES TABLE TITLE PAGE l 3.1 - I Turboprop usage by certified route carriers 6 3.1-II Model 501-D13 ratings 10 3.2.1- I 501-D13 and 606 Propeller flight hours, unit exchange airplanes 15 3.2.1-11 Summary of major engine unit removals 16 3.2.1-III Power section ( less turbine) premature k removals 17 3.2.1-IV Turbine section premature removals 18 3.2.1-V Reduction gear premature removals 19 3.2.1-VI Torquemeter premature removals 20 3.2.1-VII Non-engine responsible premature removals 21 3.2.1-VIII Propeller regulator premature removals 22 3.2.1-IX Propeller hub and blade assembly premature removals 23 3.2.1-X Non - propelle- responsible premature removals and time expiration 24 3.2.3.1.2-I Summary of Frontier Airlines 606 Propeller assembly removals 32 3.2.3.1 .