U Delmar Ellis UNTIL RECENTLY selection aircraft turbine-powered flight left choose between scratch-built ducted-fan conversion model AMA previously acquired IPX engine turbine evaluation after some consideration Bob Violett Models BVM Maverick ducted-fan kit selected compatible test airframe JMP Starfire considered equipment alternative has since proven equally successful Donnie Beauvaise Tom Robertson Starfire project actually completed advance Maverick both flying now observed recent Turbine America event Muncie original AMA test plan altered test Hot Flash Terry Nitschs highly modified Sagittario open engine mounting external fuselage also gave us time figure out cram radio engine ducting nearly impossible fuselage envelope Maverick Starfire tight fit Maverick nearly unachievable frustrating thing knowing could doneKent Nogy did equally tight Ultraviper design solutions duct configuration kept under proprietary wraps faced entire design problem chosen larger model such T-33 installation would have straightforward decided use sport model nearly undoing addition personnel changes volunteer committee resulted Maverick becoming oneperson project Now become real test Actually Maverick very straightforward assemble Both plans instrnctions very complete complete portfolio assembly photographs Kit quality fit absolutely tops hundreds graphite moldings bulkheads spars fittings Aircraft features included split flaps nosegear-mounted airbrake surface 34 Model Aviation model modified Bob Violett Models Maverick rest Conversion ducted-fan turbine power quite challengea tight fit full top hatch openings nose aft fuselage graphite spars plug-in receptacles air-actuated wheel brakes tip tanks later deleted model built per instructions except substitution handcarved wingtips instead tip tanks use medium-weight glass main wings key redesign problem providing adequate flowpath fabricating components Considerations included space utilization I stable acceptable performance adequate cooling installation first attempted breakthrough occurred procurement graphite engine shroud imported English design intended fit T-33 couldnt get Maverick because diameter length would place engine well aft target location behind top hatch opening also placed CG well aft limits considering engine weight Alternatives cut shroud up reduce size refabricate required size rework approach tried first least determine minimum size limits resulted shroud minimum length diameter placing engine maximum forward location minimum shroud openingjust barely allowing engine inserted through opening little bending good feature direct fit shroud BVM fan inlet assembly fan flowpath inner hub trimmed forward strut conical centerbody installed fair flow engine actually mounted far forward extend inlet inch within aft end centerbody engine mounted standard JPX split rings wing extensions both sides BVM servo mount brackets graphite L section structures glued fuselage sides ood backup plates formed bolt attachment ledges bolt engine strap mounts Since strap mounts extend outward through shroud horizontal split line shroud hatch cut form semicircle worked fine except hatch could hingedit would interfere Maverick top hatch An elastic double-strap restraint using Velcro quick-release adapted original idea shroud hatch attachment shroud minimized size fit extremely tight engine installed shroud hatch interfered engine throttle valve would close tightly resolved cutting out pocket installing molded clear plastic form-fitting insert Now shroud hatch fit down tight Maverick hatch now interfered After iterative adjustments everything fitted simultaneously less /16 clearance other thingthe shroud could positioned engine/airflow centerline because interference shroud fuselage cross-formers wing mount locations Giant cross-slots cut shroud later sealed around cross-formers hightemperature silicone RTV tops cross-formers trimmed significantly allow cooling flow around engine Dont go too far will lose wing restraint strength Once shroud slid place forward over fan inlet pushed down enclose cross-members shroud locks place still needs downward restraint aft end keep centered accomplished half-ring mounted fuselage top 36 Model Aviation ine field kit Note handy tote-cart purchased ElectroDynamics 31185 Schoolcraft Livonia Ml 48150 Engine hatch removed Model part ongoing AMA test program evaluate JPX turbine Front cavity filled finished Note propane fuel tanktoo large fit anywhere No room pilot cockpit either behind Maverick top hatch opening half-ring also bottom fuselage former similar location have several holes allow secondary cooling air pass through Extra cooling air introduced adding external NACA scoops top bottom hatch areas other ducting issue fabricating metal tailpipe Tudor Machining came rescue again 004 titanium-wall concentric double-duct flowpath built measured Maverick dimensions Tudor also source shroud molded insert Inner outer ducts coupled corrugated liner provide stiffness minor flow blockage Additional corrugated titanium fashioned supports between outer duct plywood ring bonded inside aft fuselage forward duct end press-fit shroud bonded high-temperature silicone next major obstacles fuel- oil-tank placement no options oil tank needs positioned bottom fuselage located higher oil will siphon engine after shutdown fuel tank too large fit anywhere finally placed half-in/half-out forward fuselage other half extends forward canopy no room scale pilot cockpit Fl forward former must cut down lower tank sufficiently close canopy over Since almost crossbrace part former remained reinforced graphite oil tank under fuel tank immediately front inlet duct Y Oil tap engine compressor air tap retract/brake air reservoir connector neatly mounted wooden plate over oil tank behind fuel tank beginning understand things getting tighter correct still needed room seven servos fuselage four wing two air reservoirs brakes retracts nose gear radio batteries room two elevator servos traditional BVM location aft wing spar cross-members bottom fuselage switch wheel brakes operated full down-elevator Unfortunately engine shroud takes up location specified plans brake switch An alternate location aft elevator servo sufficient space because taper shroud junction tailpipe rudder servo fits per original plan just forward shroud foam-wrapped reservoirs just fit cavity other side nosegear steering servo positioned under fuel tank just aft Fl former along retracted nosegear engine throttle servo mounts next plug-in mounting plate partially cut away make space forward hatch top area Its linkage carefully fed through fuselage cavities forward compartment engine shroud short length graphite arrowshaft used since very high servo loads would otherwise bend linkage Battery radio receiver located nose partitioned forward front hatch leaves remainder forward hatch section front Fl former nosegear mount retract servo air switch main gear fuel tank emergency shutoff servo Because loads tank valve tends freeze JR 472 high-capacity servo utilized fuel tank valve reworked angle down fuselage cavity just right Radio leads fuel lines oil lines required careful programming available remaining space Space utilization exceeds 80% engine shroud nose Final installation orderly unavoidably busy end result high density packaging total dry weight 15/4 pounds would have higher forward engine location eliminated need nose balance weight Hows luck CG right money Initial testing showed outer fuselage temperatures remaining below 1 100F extended running 100 percent power ground Total fuel bum including ground startup 6 minutes because smallest-available tank would fit fuselage initial flight conducted Terry Nitsch outstanding flight characteristics Maverick extended wonderful endless power WX turbine engine uprated 14 pounds takeoff thrust converted T250 configuration Top speeds unmentionably high Smooth flying characteristics Maverick fully retained including slow controllable landing characteristics Now flying its easier say its worth Given alternative current models expressly designed turbines isnt realistic choice Now someone would kit sport models little additional space fuel . ar Ellis February 1997 37 Elevator servo wheel brake air switch Note setscrew adjustment Brakes operate full down-elevator command Close quarters Throttle servo pushrod oil tap compressor air tap air reservoir fill valve Modified fan inlet conical centerbody Engine extends inch inlet within 12 inch centerbody
Edition: Model Aviation - 1997/02
Page Numbers: 34, 36, 37
Edition: Model Aviation - 1997/02
Page Numbers: 34, 36, 37
U Delmar Ellis UNTIL RECENTLY selection aircraft turbine-powered flight left choose between scratch-built ducted-fan conversion model AMA previously acquired IPX engine turbine evaluation after some consideration Bob Violett Models BVM Maverick ducted-fan kit selected compatible test airframe JMP Starfire considered equipment alternative has since proven equally successful Donnie Beauvaise Tom Robertson Starfire project actually completed advance Maverick both flying now observed recent Turbine America event Muncie original AMA test plan altered test Hot Flash Terry Nitschs highly modified Sagittario open engine mounting external fuselage also gave us time figure out cram radio engine ducting nearly impossible fuselage envelope Maverick Starfire tight fit Maverick nearly unachievable frustrating thing knowing could doneKent Nogy did equally tight Ultraviper design solutions duct configuration kept under proprietary wraps faced entire design problem chosen larger model such T-33 installation would have straightforward decided use sport model nearly undoing addition personnel changes volunteer committee resulted Maverick becoming oneperson project Now become real test Actually Maverick very straightforward assemble Both plans instrnctions very complete complete portfolio assembly photographs Kit quality fit absolutely tops hundreds graphite moldings bulkheads spars fittings Aircraft features included split flaps nosegear-mounted airbrake surface 34 Model Aviation model modified Bob Violett Models Maverick rest Conversion ducted-fan turbine power quite challengea tight fit full top hatch openings nose aft fuselage graphite spars plug-in receptacles air-actuated wheel brakes tip tanks later deleted model built per instructions except substitution handcarved wingtips instead tip tanks use medium-weight glass main wings key redesign problem providing adequate flowpath fabricating components Considerations included space utilization I stable acceptable performance adequate cooling installation first attempted breakthrough occurred procurement graphite engine shroud imported English design intended fit T-33 couldnt get Maverick because diameter length would place engine well aft target location behind top hatch opening also placed CG well aft limits considering engine weight Alternatives cut shroud up reduce size refabricate required size rework approach tried first least determine minimum size limits resulted shroud minimum length diameter placing engine maximum forward location minimum shroud openingjust barely allowing engine inserted through opening little bending good feature direct fit shroud BVM fan inlet assembly fan flowpath inner hub trimmed forward strut conical centerbody installed fair flow engine actually mounted far forward extend inlet inch within aft end centerbody engine mounted standard JPX split rings wing extensions both sides BVM servo mount brackets graphite L section structures glued fuselage sides ood backup plates formed bolt attachment ledges bolt engine strap mounts Since strap mounts extend outward through shroud horizontal split line shroud hatch cut form semicircle worked fine except hatch could hingedit would interfere Maverick top hatch An elastic double-strap restraint using Velcro quick-release adapted original idea shroud hatch attachment shroud minimized size fit extremely tight engine installed shroud hatch interfered engine throttle valve would close tightly resolved cutting out pocket installing molded clear plastic form-fitting insert Now shroud hatch fit down tight Maverick hatch now interfered After iterative adjustments everything fitted simultaneously less /16 clearance other thingthe shroud could positioned engine/airflow centerline because interference shroud fuselage cross-formers wing mount locations Giant cross-slots cut shroud later sealed around cross-formers hightemperature silicone RTV tops cross-formers trimmed significantly allow cooling flow around engine Dont go too far will lose wing restraint strength Once shroud slid place forward over fan inlet pushed down enclose cross-members shroud locks place still needs downward restraint aft end keep centered accomplished half-ring mounted fuselage top 36 Model Aviation ine field kit Note handy tote-cart purchased ElectroDynamics 31185 Schoolcraft Livonia Ml 48150 Engine hatch removed Model part ongoing AMA test program evaluate JPX turbine Front cavity filled finished Note propane fuel tanktoo large fit anywhere No room pilot cockpit either behind Maverick top hatch opening half-ring also bottom fuselage former similar location have several holes allow secondary cooling air pass through Extra cooling air introduced adding external NACA scoops top bottom hatch areas other ducting issue fabricating metal tailpipe Tudor Machining came rescue again 004 titanium-wall concentric double-duct flowpath built measured Maverick dimensions Tudor also source shroud molded insert Inner outer ducts coupled corrugated liner provide stiffness minor flow blockage Additional corrugated titanium fashioned supports between outer duct plywood ring bonded inside aft fuselage forward duct end press-fit shroud bonded high-temperature silicone next major obstacles fuel- oil-tank placement no options oil tank needs positioned bottom fuselage located higher oil will siphon engine after shutdown fuel tank too large fit anywhere finally placed half-in/half-out forward fuselage other half extends forward canopy no room scale pilot cockpit Fl forward former must cut down lower tank sufficiently close canopy over Since almost crossbrace part former remained reinforced graphite oil tank under fuel tank immediately front inlet duct Y Oil tap engine compressor air tap retract/brake air reservoir connector neatly mounted wooden plate over oil tank behind fuel tank beginning understand things getting tighter correct still needed room seven servos fuselage four wing two air reservoirs brakes retracts nose gear radio batteries room two elevator servos traditional BVM location aft wing spar cross-members bottom fuselage switch wheel brakes operated full down-elevator Unfortunately engine shroud takes up location specified plans brake switch An alternate location aft elevator servo sufficient space because taper shroud junction tailpipe rudder servo fits per original plan just forward shroud foam-wrapped reservoirs just fit cavity other side nosegear steering servo positioned under fuel tank just aft Fl former along retracted nosegear engine throttle servo mounts next plug-in mounting plate partially cut away make space forward hatch top area Its linkage carefully fed through fuselage cavities forward compartment engine shroud short length graphite arrowshaft used since very high servo loads would otherwise bend linkage Battery radio receiver located nose partitioned forward front hatch leaves remainder forward hatch section front Fl former nosegear mount retract servo air switch main gear fuel tank emergency shutoff servo Because loads tank valve tends freeze JR 472 high-capacity servo utilized fuel tank valve reworked angle down fuselage cavity just right Radio leads fuel lines oil lines required careful programming available remaining space Space utilization exceeds 80% engine shroud nose Final installation orderly unavoidably busy end result high density packaging total dry weight 15/4 pounds would have higher forward engine location eliminated need nose balance weight Hows luck CG right money Initial testing showed outer fuselage temperatures remaining below 1 100F extended running 100 percent power ground Total fuel bum including ground startup 6 minutes because smallest-available tank would fit fuselage initial flight conducted Terry Nitsch outstanding flight characteristics Maverick extended wonderful endless power WX turbine engine uprated 14 pounds takeoff thrust converted T250 configuration Top speeds unmentionably high Smooth flying characteristics Maverick fully retained including slow controllable landing characteristics Now flying its easier say its worth Given alternative current models expressly designed turbines isnt realistic choice Now someone would kit sport models little additional space fuel . ar Ellis February 1997 37 Elevator servo wheel brake air switch Note setscrew adjustment Brakes operate full down-elevator command Close quarters Throttle servo pushrod oil tap compressor air tap air reservoir fill valve Modified fan inlet conical centerbody Engine extends inch inlet within 12 inch centerbody
Edition: Model Aviation - 1997/02
Page Numbers: 34, 36, 37
U Delmar Ellis UNTIL RECENTLY selection aircraft turbine-powered flight left choose between scratch-built ducted-fan conversion model AMA previously acquired IPX engine turbine evaluation after some consideration Bob Violett Models BVM Maverick ducted-fan kit selected compatible test airframe JMP Starfire considered equipment alternative has since proven equally successful Donnie Beauvaise Tom Robertson Starfire project actually completed advance Maverick both flying now observed recent Turbine America event Muncie original AMA test plan altered test Hot Flash Terry Nitschs highly modified Sagittario open engine mounting external fuselage also gave us time figure out cram radio engine ducting nearly impossible fuselage envelope Maverick Starfire tight fit Maverick nearly unachievable frustrating thing knowing could doneKent Nogy did equally tight Ultraviper design solutions duct configuration kept under proprietary wraps faced entire design problem chosen larger model such T-33 installation would have straightforward decided use sport model nearly undoing addition personnel changes volunteer committee resulted Maverick becoming oneperson project Now become real test Actually Maverick very straightforward assemble Both plans instrnctions very complete complete portfolio assembly photographs Kit quality fit absolutely tops hundreds graphite moldings bulkheads spars fittings Aircraft features included split flaps nosegear-mounted airbrake surface 34 Model Aviation model modified Bob Violett Models Maverick rest Conversion ducted-fan turbine power quite challengea tight fit full top hatch openings nose aft fuselage graphite spars plug-in receptacles air-actuated wheel brakes tip tanks later deleted model built per instructions except substitution handcarved wingtips instead tip tanks use medium-weight glass main wings key redesign problem providing adequate flowpath fabricating components Considerations included space utilization I stable acceptable performance adequate cooling installation first attempted breakthrough occurred procurement graphite engine shroud imported English design intended fit T-33 couldnt get Maverick because diameter length would place engine well aft target location behind top hatch opening also placed CG well aft limits considering engine weight Alternatives cut shroud up reduce size refabricate required size rework approach tried first least determine minimum size limits resulted shroud minimum length diameter placing engine maximum forward location minimum shroud openingjust barely allowing engine inserted through opening little bending good feature direct fit shroud BVM fan inlet assembly fan flowpath inner hub trimmed forward strut conical centerbody installed fair flow engine actually mounted far forward extend inlet inch within aft end centerbody engine mounted standard JPX split rings wing extensions both sides BVM servo mount brackets graphite L section structures glued fuselage sides ood backup plates formed bolt attachment ledges bolt engine strap mounts Since strap mounts extend outward through shroud horizontal split line shroud hatch cut form semicircle worked fine except hatch could hingedit would interfere Maverick top hatch An elastic double-strap restraint using Velcro quick-release adapted original idea shroud hatch attachment shroud minimized size fit extremely tight engine installed shroud hatch interfered engine throttle valve would close tightly resolved cutting out pocket installing molded clear plastic form-fitting insert Now shroud hatch fit down tight Maverick hatch now interfered After iterative adjustments everything fitted simultaneously less /16 clearance other thingthe shroud could positioned engine/airflow centerline because interference shroud fuselage cross-formers wing mount locations Giant cross-slots cut shroud later sealed around cross-formers hightemperature silicone RTV tops cross-formers trimmed significantly allow cooling flow around engine Dont go too far will lose wing restraint strength Once shroud slid place forward over fan inlet pushed down enclose cross-members shroud locks place still needs downward restraint aft end keep centered accomplished half-ring mounted fuselage top 36 Model Aviation ine field kit Note handy tote-cart purchased ElectroDynamics 31185 Schoolcraft Livonia Ml 48150 Engine hatch removed Model part ongoing AMA test program evaluate JPX turbine Front cavity filled finished Note propane fuel tanktoo large fit anywhere No room pilot cockpit either behind Maverick top hatch opening half-ring also bottom fuselage former similar location have several holes allow secondary cooling air pass through Extra cooling air introduced adding external NACA scoops top bottom hatch areas other ducting issue fabricating metal tailpipe Tudor Machining came rescue again 004 titanium-wall concentric double-duct flowpath built measured Maverick dimensions Tudor also source shroud molded insert Inner outer ducts coupled corrugated liner provide stiffness minor flow blockage Additional corrugated titanium fashioned supports between outer duct plywood ring bonded inside aft fuselage forward duct end press-fit shroud bonded high-temperature silicone next major obstacles fuel- oil-tank placement no options oil tank needs positioned bottom fuselage located higher oil will siphon engine after shutdown fuel tank too large fit anywhere finally placed half-in/half-out forward fuselage other half extends forward canopy no room scale pilot cockpit Fl forward former must cut down lower tank sufficiently close canopy over Since almost crossbrace part former remained reinforced graphite oil tank under fuel tank immediately front inlet duct Y Oil tap engine compressor air tap retract/brake air reservoir connector neatly mounted wooden plate over oil tank behind fuel tank beginning understand things getting tighter correct still needed room seven servos fuselage four wing two air reservoirs brakes retracts nose gear radio batteries room two elevator servos traditional BVM location aft wing spar cross-members bottom fuselage switch wheel brakes operated full down-elevator Unfortunately engine shroud takes up location specified plans brake switch An alternate location aft elevator servo sufficient space because taper shroud junction tailpipe rudder servo fits per original plan just forward shroud foam-wrapped reservoirs just fit cavity other side nosegear steering servo positioned under fuel tank just aft Fl former along retracted nosegear engine throttle servo mounts next plug-in mounting plate partially cut away make space forward hatch top area Its linkage carefully fed through fuselage cavities forward compartment engine shroud short length graphite arrowshaft used since very high servo loads would otherwise bend linkage Battery radio receiver located nose partitioned forward front hatch leaves remainder forward hatch section front Fl former nosegear mount retract servo air switch main gear fuel tank emergency shutoff servo Because loads tank valve tends freeze JR 472 high-capacity servo utilized fuel tank valve reworked angle down fuselage cavity just right Radio leads fuel lines oil lines required careful programming available remaining space Space utilization exceeds 80% engine shroud nose Final installation orderly unavoidably busy end result high density packaging total dry weight 15/4 pounds would have higher forward engine location eliminated need nose balance weight Hows luck CG right money Initial testing showed outer fuselage temperatures remaining below 1 100F extended running 100 percent power ground Total fuel bum including ground startup 6 minutes because smallest-available tank would fit fuselage initial flight conducted Terry Nitsch outstanding flight characteristics Maverick extended wonderful endless power WX turbine engine uprated 14 pounds takeoff thrust converted T250 configuration Top speeds unmentionably high Smooth flying characteristics Maverick fully retained including slow controllable landing characteristics Now flying its easier say its worth Given alternative current models expressly designed turbines isnt realistic choice Now someone would kit sport models little additional space fuel . ar Ellis February 1997 37 Elevator servo wheel brake air switch Note setscrew adjustment Brakes operate full down-elevator command Close quarters Throttle servo pushrod oil tap compressor air tap air reservoir fill valve Modified fan inlet conical centerbody Engine extends inch inlet within 12 inch centerbody
