1979017874 :.m NASA ContractorReport CR 159002 ' (_&SA-CR-159002) AIR CUSRION LAHDING GEAR R79-26045 APPLIC&TIOqS STUDY Report, Jan. - _ar. 1979 -: (Textron Bell Aerospace Co., P-uffalo, N. 7.) : 83 p HC AO5/nF A01 CSCL 01C G3/05 26027Unclas ! _'' MR CUSHION LANDING GEAR _ APPLICATIONS STUDY _ "I • .;_. -._ T.D. EARL :: -::, BUFFALO,BELL AERNYOSPACE14240 TEXTRON i! -.. _,EPORT NO. D7605-927002 "_ APRIL 1979 ' _ "! CONTRACT NAS 1-15202 i II ._-¢ f 7 i ' .! I -_ , ____ Naliona,Aeronautics and -"_'_ ,_/ '" ,. SloaceAdministration _c-'_,, "_Z'. d_'_ ! ' LangleyResearchCenter , .... _ HamptonVirginia, 23665 __ AC 804 827-3966 ',i / 1979017874-002 4j"_ ....................... ! g f NASAContractorReportCR159002 t' " AIR CUSHION LANDING GEAR ; APPLICATIONS STUDY _: !" T.D. EARL _ ' BELL AEROSPACE TEXTRON i BUFFALO,NY 14240 ! REPORT NO. D760S-927002 APRIL 1979 CONTRACTNAS 1 15202 • _ NationalAeronauticsand SpaceAdministration ,, LangleyResearchCenter ! Hampton,Virginia23665 AC804 827-3966 t 1979017874-003 7 CONTENTS FOREWORD .......................................................... vii ,_ ACKNOWLEDGEMENT.................................................. vii SUMMARY ............................................................ viii INTRODUCTION ...................................................... 1 LIST OF ACRONYMS/ABBREVIATIONS .................................... ix General .............................................................. I ACLG Background.. ..................................................... 1 i ! Operating Principles .................................................... 1 " Advantages ............................................................ 3 "_ ' Objectives and Study Scope 4 New ACLG Configuration • o.................... • . • . ° • . • • *** , ° .. °. • , . , ,o . ° 6 '_ SELECTED APPLICATIONS .............................................. 10 "_ : APPLICATIONDESCRIPTIONS AND ANALYSIS OF BENEFITS ................ 12 General Aviation Amphibian (GAA) ........................................ 12 ' i_ Light Amphibious Transport (LAT) ..... •................................... 22 • Short Haul Amphibian (SHA) ............................................... 26 Medium Amphibious Transport (MAT)....................................... 34 _i , _ Large Multi-Mission Amphibian (LM/A) ...................................... 39 _ : _ Off-Runway Tactical Fighter (OTJT) ............... '......................... 45 _: _, Remotely Piloted Vehicle (RPV/Y .......................................... 48 '_ Wing In Ground Effect (WIG) .............................................. 51 _' SURVEY AND EVALU_'rlON ............................................ 52 ,_ TECItNOLOGY DEVELOPMENT SCENARIO ................................ 54 Overview ..... _./........................................................ 54 Discussion of ffurrent Technology Base ...................................... 57 m ' • Development Timetables ................................................... 68 ./ • CONCI_USIONS AND RECOMMENDATIONS .................................70 REFERENCES 72 H, _' 111 1979017874-004 ILLUSTRATIONS __, Figure Page 1 The deHavilland-Buffalo, LA-4 and Jindivik on Air Cushion ................. 2 2 ACLG Operating Principles ........................................... 3 3 LA-4 Operating Over Land, Water and Snow ............................. 4 4 Part Water, Part Land Ground Roll Feature of an Aircraft with ACLG ......... 5 5 Inherent Kneeling Feature of Aircraft with ACLG ......................... 5 . e 6 General Aviation Design ............................................. 6 7 Air Cushion Planform Comparison ..................................... 8 8(a) Cross Section Comparison and Stretch Diagram .......................... 8 8(b) Frontal View Comparison .......................................... 9 0 9 Transport Applications ............................................. 11 10 General Aviation Design Landing Configuration ........................... 13 11 General Aviation Design Configured as an Ambulance ..................... 13 12 General Aviation Design as Light Freighter, Parked on Snow ................. 14 13 GAA 3-View ..................................................... 15 14 GAA Inboard Profile ............................................... 16 15 Compmative Accommodation ......................................... 19 16 Operating Cost Comparisons ......................................... 19 17 1/4-Scale LA-4 Model Overwater Drag Data (Full-Scale Values) ............... 20 18 Equilibrium Low-Speed Taxi Conditions in Strong Crossw.ind ............... 21 19 LAT Design ....................................................... 22 20 Comparative Accommodations ....................................... 23 21 Light Amphibious Transport 3-View ................................... 23 22 LAT Economic Comparisons ......................................... 25 23 Short Haul Amphibian (3-View) ' 27 24 T-34 Inboard Profile Showing Fan Bleed and Flow Augmenter Scheme .......... 29 25 T-34-100 By-Pass Flow Characteristics ................................. 29 26 Short Haul Amphibian (SHA) ......................................... 31 27 Landing Profile Comparison ................................ ........ 33 28 Medium Amphibious Transport 3-View ................................. 34 29(a) CF6-50 Standard Engine Cross Section ... o • , • ° • • o , • • , • I , ° _ • i • ° o • • , , • ° I • 35 29(b) CF6-50 Engine Showing Proposed Modification for ACLG Fan Bleed ......... 35 ': 30 Size Comparison of YC-; 4 with Medium Anlphibious Transport ACLGConcept. 36 " 31 Variation of Range Factor (Thrust Horsepower per Pound of Fuel) with Altitude ......................... 2;7 : ,o.ll°,e,.,_,,o,,_,ol Je,°o m ! 32 Estimated Range - Payload Comparison of MAT with YC-14 ................. 38 33 Cost Comparison...' ................................................ 39 34 Large Multi-Mission Amphibian (LMA) ................................. 40 • _t 35 Typical LMACross Sec'tion " 40 ] 36 LMA/759-182A Comparison ......................................... 41 37 Operating Cost Comparison ......................................... 44 38 Productivity Comparison ..................... , ..................... 44 i 39 Off-Runway Tact!cal Fighter ' , .................. : .......... 45 40 OTF Artist's Concept ............................................... 46 ! iv 1979017874-005 ILLUSTRATIONS (CONT) Figure Page "_ I 41 OTF Range and Endurance ......................................... 47 42 OTF Speed Envelope .............................................. 47 " 43 Jindivik 3-View ................................................. 49 44 Jindivik ACLG System " 49 • 45 RPV Recovexy Costs .............................................. 50 . 46 Preliminary Conceptual Design of WIG ................................ 51 ] 47 ASNAP Analysis Correlation to Measured Loads .......................... 59 ', 48 ACLS Flutter Analysis Idealization .................................... 60 49 Air Lubrication Test Results ........................................ 62 50 Rubber Fatigue .................................................. 64 1979017874-006 TABLES Number Page _ ! Problems Encountered in the deHavilland-Buffalo Program ....................... 7 11 Transport Applications ................................................... 10 11I Fighter, RPV and WIG Applications ......................................... 12 IV Estimated GAA Characteristics ............................................. 17 V GAA Weight Breakdown ................................................... 18 V! GAA Ai/Cushion Gear Cost ................................................. 21 . _: VII GAA Market Potential ..................................................... 21 VIII Comparison of Characteristics ............................................... 24 ; IX Comparison of SHA Design and Boeing 737-100 ................................. 28 X Non-Fatal Incidents ....................................................... 32 XI SHA and Boeing 737-100 Landing Gear Costs ................................... 33 XII l/10 Scale C-8 Model Water Landing Tests, Simulated 5 ft Waves ................... 41 Xill LMA/759-182A Weight Breakdown ......................................... 42 XIV LMA ACLG Weight Breakdown ............................................. 42 XV Comparison of Performance Characteristics of the LMA Design with Two Boeing Aircraft ....................................................... 43 XVi OTF Design Principal Characteristics ......................................... 46 XVI! OTF Weight Summary ..................................................... 47 XVlll OTF Performance at 6,351 kg (14,000 lb) GW ................................. 48 XIX Light Trainer/Ground Attack Aircraft ................... •....................... 48 XX ACLG Jindivik Principal Characteristics ....................................... 50 XXI WIG Characteristics ....................................................... 52 XXll Categories Established By NASA for Study ..................................... 55 XXIII ACLG Applications ....................................................... 56 XXIV Math Model Simulations of 1/4 - and Full-Scale ACLS Trunk Flutter ................. 60 XXV XC-8A Partial History .......................................... •........... 65 XXV! Comparative Landing Kinetic Energy Absorption Parameters ....................... 67 XXVII Technology Development Requirements ....................................... 68 XXVlll ACLG Technology Development Timetable ..................................