A B THERE IS little doubt ducted fans rapidly becoming standard accepted part model aviation WRAMS Toledo Shows earlier year saw introduction number aircraft kits designed around ducted fan powerplants various sizes types scratch builders havent forgotten fan projects showing up model press ducted fans will modelers bag some complexity good engine operation knowledge required attention must paid mechanical details willing rewards can greata scale jet model flying across sky non-scale prop nose glorious sight factor must taken account flying ducted fan model amount thrust available fan models can fly well general takeoff runs longer acceleration slower climb-outs shal lower traditional prop-driven aircraft ducted fan manufacturers have expended tremendous amount research develop ment effort has resulted fans now available us designer Midwest Products Axiflo series ducted fans Mr Bob Kress continues II 1 Whats latest ducted fan tech nology author rare oppor tunity testing Bob Kress prototype tan dem Mini F-16 presented July 1980 issue tandem allows 09 049-size pack ageand really puts out thrust yet commercially available U Dick Sarpolus 111111 2dA1 IL press state-of-the-art ducted fan design Several Kress ducted fan articles have appeared RCM MB magazines first design Midwest 40-size Axiflo followed 049 Axiflo both construction kits requiring bit time skill part modeler third Midwest product Axiflo RK-20B big step forward ducted fan unit made up completely molded sub-assemblies require bolting gether ready use quest improved performance Kress latest innovation tandem fan presented have opportunity test fly prototype tandem fan model own can attest its performance will attempt describe what has developed interest modelers following ducted fan technology product reviewthe tandem fan concept yet available commercially Mr Kress obtaining patent coverage devel opment later date double-fan units will produced Dont look right now Ducted fans have designed use much power possible given diameter get much thrust possible diameter Any aircraft must designed around fan unit size weight hopefully will permit 58 Model Aviation prototype tandem fan disassembled showing two fans mounted together directly iine shead 09 engine front fan housing rIght has besring support fan shaft within stator assembly Spinner mounts front shaft electric starting LI Iw good performance available thrust Any substantial increase thrust given diameter will make aircraft designers task much easier appears tandem fan concept Kress has able stuff larger therefore powerful engine given diameter resulting thrust prototype tandem fan uses 09 engine overall package size existing 049 conventional unit Looking ahead forecasts 40-powered double-fan 20-size package 60 power 40-size package resultant higher thrust-tosize ratio will give us better perfonning aircraft am aerodynamic engineer must leave technical discussion double-fan Mr Kress future have run prototype 09 tandem fan felt thrust flown model itthe results immediately apparent impressive Before getting test flights photos show general layout unit two fans mounted together directly line front end fan shaft supported bearing located fixed stator assembly front fan housing spinner mounts front shaft engine started normally electric starter entire package disassembles similarly Axiflo RK-20B looks though could easily molded plastic prototype built-up incidentally workmanship excellent added small fuel tank approxi mately two ounces back engine mount assembly flight testing Fortunately available test model Mini F-16 presented July 1980 issue ModelAviation originally designed around Axiflo 049 two F-16 models easily converted original heavier model accept 09 tandem fan package photos show both models both fan units compari son Please refer F- 16 article additional comments 049 fan installation operation Immediately upon hand-launching tandem fan-powered model its first test flight reaction hearty laugh seeing well model performed slight additional weight 09 over 049 course compensated increased thrust available 049 model fun fly calls careful handling due thrust availablethe 09 tandem fan really performs certainly feel tandem fan concept repre sents real step forward ducted fan technology look forward Bob Kress further develop ment idea thought 20- 40powered tandem fan units has anxious begin some new aircraft designs Well have wait patiently fan idea further proven refined hopefully become available us autnor pressed two ni F-i 69 service comparing tandem single units tandem square-bottom plane both pictures bottom-side view hatches removed note both fan units take up about same amount space Tandem slightly heavier January 1981 59 Dick Sarpolus left flying buddy Dick Newcomb putting own 049 Mini F-16 through Its paces Another memberof Dicks club familiarwith 049 models perform ance knowing 09 tandem fan inside heard say did get much power 049 Truly theres impressive difference flight performance ness two snots snow mat overall size tandem unit tien ian picture rignt rignt picxurej just aoouttne same tne u49 single fan unit shown alongside both cases fuel tank mounted directly behind engine Fill vent pressure lines run outside
Edition: Model Aviation - 1981/01
Page Numbers: 58, 59
A B THERE IS little doubt ducted fans rapidly becoming standard accepted part model aviation WRAMS Toledo Shows earlier year saw introduction number aircraft kits designed around ducted fan powerplants various sizes types scratch builders havent forgotten fan projects showing up model press ducted fans will modelers bag some complexity good engine operation knowledge required attention must paid mechanical details willing rewards can greata scale jet model flying across sky non-scale prop nose glorious sight factor must taken account flying ducted fan model amount thrust available fan models can fly well general takeoff runs longer acceleration slower climb-outs shal lower traditional prop-driven aircraft ducted fan manufacturers have expended tremendous amount research develop ment effort has resulted fans now available us designer Midwest Products Axiflo series ducted fans Mr Bob Kress continues II 1 Whats latest ducted fan tech nology author rare oppor tunity testing Bob Kress prototype tan dem Mini F-16 presented July 1980 issue tandem allows 09 049-size pack ageand really puts out thrust yet commercially available U Dick Sarpolus 111111 2dA1 IL press state-of-the-art ducted fan design Several Kress ducted fan articles have appeared RCM MB magazines first design Midwest 40-size Axiflo followed 049 Axiflo both construction kits requiring bit time skill part modeler third Midwest product Axiflo RK-20B big step forward ducted fan unit made up completely molded sub-assemblies require bolting gether ready use quest improved performance Kress latest innovation tandem fan presented have opportunity test fly prototype tandem fan model own can attest its performance will attempt describe what has developed interest modelers following ducted fan technology product reviewthe tandem fan concept yet available commercially Mr Kress obtaining patent coverage devel opment later date double-fan units will produced Dont look right now Ducted fans have designed use much power possible given diameter get much thrust possible diameter Any aircraft must designed around fan unit size weight hopefully will permit 58 Model Aviation prototype tandem fan disassembled showing two fans mounted together directly iine shead 09 engine front fan housing rIght has besring support fan shaft within stator assembly Spinner mounts front shaft electric starting LI Iw good performance available thrust Any substantial increase thrust given diameter will make aircraft designers task much easier appears tandem fan concept Kress has able stuff larger therefore powerful engine given diameter resulting thrust prototype tandem fan uses 09 engine overall package size existing 049 conventional unit Looking ahead forecasts 40-powered double-fan 20-size package 60 power 40-size package resultant higher thrust-tosize ratio will give us better perfonning aircraft am aerodynamic engineer must leave technical discussion double-fan Mr Kress future have run prototype 09 tandem fan felt thrust flown model itthe results immediately apparent impressive Before getting test flights photos show general layout unit two fans mounted together directly line front end fan shaft supported bearing located fixed stator assembly front fan housing spinner mounts front shaft engine started normally electric starter entire package disassembles similarly Axiflo RK-20B looks though could easily molded plastic prototype built-up incidentally workmanship excellent added small fuel tank approxi mately two ounces back engine mount assembly flight testing Fortunately available test model Mini F-16 presented July 1980 issue ModelAviation originally designed around Axiflo 049 two F-16 models easily converted original heavier model accept 09 tandem fan package photos show both models both fan units compari son Please refer F- 16 article additional comments 049 fan installation operation Immediately upon hand-launching tandem fan-powered model its first test flight reaction hearty laugh seeing well model performed slight additional weight 09 over 049 course compensated increased thrust available 049 model fun fly calls careful handling due thrust availablethe 09 tandem fan really performs certainly feel tandem fan concept repre sents real step forward ducted fan technology look forward Bob Kress further develop ment idea thought 20- 40powered tandem fan units has anxious begin some new aircraft designs Well have wait patiently fan idea further proven refined hopefully become available us autnor pressed two ni F-i 69 service comparing tandem single units tandem square-bottom plane both pictures bottom-side view hatches removed note both fan units take up about same amount space Tandem slightly heavier January 1981 59 Dick Sarpolus left flying buddy Dick Newcomb putting own 049 Mini F-16 through Its paces Another memberof Dicks club familiarwith 049 models perform ance knowing 09 tandem fan inside heard say did get much power 049 Truly theres impressive difference flight performance ness two snots snow mat overall size tandem unit tien ian picture rignt rignt picxurej just aoouttne same tne u49 single fan unit shown alongside both cases fuel tank mounted directly behind engine Fill vent pressure lines run outside