LclIA Inexpensiveistrument takes guesswork out knowiw high airplane really John Brent Photos Tom Chambers Federal Aviation A&n 4easernbled less happens istration nut out recoin- old chrttit sct lying around mended mode limit 400 expensive pat t1i ThThro ipt aircraft allow reachqailibt feet Koon became ob- can purchased chemical rium tfrt4uundiflg airA tern viousand still isthat ratus supplier foIl wing parts perature barograph should no idea high interes ml icropi t graduated same ambient air out sun therefore help make altitude 1/100 m1ii s 1-- 0 mtvilupetric other heat source visible settle arguments flash glass iil r dj thewiier level can ilso very useful know sure plastic glass ~Lsh rt lengths Ty- micro pipe o arest 1/100 ml altitude looks like terms gon tubing l0 Ins e diameter tubing read altitude chart Fig 3 riodel field typical flying metal This will give actual altitude reached altimeter described can very Before proce irg ith assembly above launch site altitude such purposes can also barometer t g t works launch site added above ground fpla/water attempts RC Helicopter rec- Note diagr ig Flask should altitude arrive absolute altitude above Hut dont look help RC almost full may mean sea level ower records conventional aircraft colored fqod dye easier reading theory behind barograph dithat record well over 20000 feet How- Flask B cont irs r apparatus rectly related Charles Boyles gas ever RC glider altitude record with- assembled tl4tt tip pipet laws ie volume gas case range altimeterit calibrated within 1/8 ~mjthe bottom Flask air varies indirectly pressure sur 6000 feet current world record After asse $1 barograph per rounding gas atmosphere directly 4988 feet Fig 1 sec side aircraft up- temperature gas Calcula Due weight size recording right posit o possible pro- tions graph Fig 3 have taken barographs altimeters almost ceed with Flight maneuvers such temperature consideration based impossible establish alt itud ion t ht stunts should average 10C temp decrease for model aircraft m4ans-Reor4-vio otto invert barograph 500 feet increase altitude baro ing barographs also expeve in- avq%ft lity air escaping metric values altitude taken strument described simpfe t rike Flk $ ced out tables standard atmospheric pressures calibrate accurate within plus ease altit After case interested dif minus 50 feet weighs less 5 altitucPdt61t h rnidreturn ferential pressures actual barometric ounces will fit miniature air- aircraft ground again avoiding pressure does have known craft cost less $500 can adverse maneuvers Remove barograph actually works apparatus assembled Flask B pipet contain water small amount pipet due capillary action model ascends air Flask B expands due lower outside pres sure higher elevation Air escapes through pipet atmosphere cannot get back Flask B due water seal As aircraft goes up air escapes However note Flask B always contains exact volume air case 10 ml can volume long necessary calculations made adjust difference 10 ml actual volume Flask B including measuring pipet calculated weighing empty flask pipet combination shown Fig 2 Fill water exactly top pipet weigh weight flask plus water minus weight empty flask grams me ml very highest altitude reached Flask B contains 10 ml reduced atmos pheric pressure depending altitude As aircraft descends atmospheric 26 Model Aviation components before assembly Left Flask B 10 ml Right Flask 26 ml flask shown 10 ml works just well foreground Micro Pipet center two pieces plastic tubing small vent tube Due size weight ordinary barographs altimeters has almost impossible establish altitude verification 777 FILL TO HERE _______ WITH WATER 1OML VOL FLASK B ________ MICRO ___________ PIPET P LAST C TUBING 020 STEEL ifTUBING WATER FLASK B Lii~ FLASK 1A FIGURE IFIGURE II pressure increases outside flask forces water up micro pipet maintain equilibrium between air pressure inside Flask B atmospheric pressure Simultaneously aircraft climbed higher air Flask B decreased temperature due upper air being cooler contraction air Flask B occurred As aircraft descends air Flask B expands slightly due increase tem perature Allowing flask equilibriate ambient air permits calculations temperature effect utilize stan dard 10C per 500 feet lapse rate altitude Increases decreases effect tem perature minor taken account calculating values Fig 3 following formula used cal culating graph Fig 3 VT2P V2 volume air B after de scent V me air B altitude 10 ml lute temperature* altitude lapse rate 10C/500 feet T2 olute temperature* ground level P mperature must 0Kelvin 273 al temp 0C atmospheric pressures must mm mercury atmospheric pressure* altitude std charts P2 spheric pressure* ground level 760mm arrive difference volume air B actual volume V formula subtracted volume B 10 ml get reading 100 feet altitude barometer can read near est 50 feet accurate 100 feet graph Fig 3 usable ground elevations 0 1000 feet should recalculated higher elevations plus minus 50 feet accuracy maintained So have gang Assemble go out set some altitude records settle club disputes high can fly aircraft chart calcu lated 6000 feet due orientation problems naked eye binocu lars additional aids altitude aircraft could still controlled ground could increased experience anything above 3000 feet very difficult control visual aids club members have tried barograph have enjoyed makes interesting afternoon get together altitude attempts amazing far off guessers can January 1976 27 Above Assembled unit ready use Flask bottom contains 15 ml colored water Flask B top inverted contains air Right Unit after flight Liquid level has risen Pipet Volume liquid determines alti tude Read directly chart 10 ml volume Flask B ALTITUDE CHART Flask B l Volume V me Water PipeS AItitde is feet ubove lsech Site VAltitudeVAltitude 031 00873100 06200903200 09300933300 12400963400 14500983500 176001013600 202001 043700 238001 063800 269001 093900 2910001124000 3211001t44100 3512001174200 3713001204300 4014001224400 4315001254500 4616001384600 4917001304700 5218001334800 5419001364900 5720001385000 6021001415100 6322001 435200 6623001465300 6524001 495400 7125001515500 7426001545600 7727001565700 7929001 595800 8229001 525900 8530001 646000 FIGURE III RAT RACING has evolved good beginners event probably competitive control-line event its 20 some years existence old days form aircraft acceptable long would take off land winner usually could successfully restart engine couple times race things have changed recent years state-of-the-art has up graded both through technological im provements engines also flying techniques improvements have proven demise event Participation especially new people practically non-existent feel lack participation new blood directly attributable two areas lack available information lack pilots intent article make available potential new comer details get started event Hooptee MK III Model presented article typical modern rat racers represents third basic design change have made rat racer designs past 12 years have using design three years has such consistent performer other top competitors Midwest area now using also include Bill Allen John Ballard Gary Fentress Bob Finely Pat Flinn quite easy construct once have gone through exercise time two first time through may scare bit due un usual construction technique namely fiberglass top future models will become quite easy confidence improves HOOPTE*B MKIIL updde c ro racing John F Kilsdonk first step select engine As writing HP-40 RRV engine popular However enough work being put OS-405R some day should least rank equal better HP Other 40-size engines avail able however passes both qualities absolutely necessary good rat engine high performance fast re start capability Whatever engine select start should fitted Midwest former ly Harters pinto speed pan can obtained through good hobby shop pan will require some grinding mount engine modifications pan should kept minimum structually weaken engine mounted using 4-40 X s requires drilling tapping pan after locating engine next step install landing gear single wheel landing gear shown plans has proven very popular because its ease installation extreme durability An 1/8 hole drilled through inboard side dimple location pan Another /8 hole drilled approximately 1 rear wing mounting boss pan Select 15 18 length of/g piano wire make two right angle bends same plane approximately middle piece center distance bends should correspond exactly center distance two landing gear holes Both holes drilled pan should radiused top accept radius piano wire bends Slip piano wire through two holes lightly tap place until well seated point Above Basic components prior assembly Below Finished wing engine/pen assembly fiberglass fuselage top has cut out match engine wing Leadout tubes covered basswood strips wing tip weight place its special cut-Out 28 Model Aviation
Edition: Model Aviation - 1976/01
Page Numbers: 26, 27
LclIA Inexpensiveistrument takes guesswork out knowiw high airplane really John Brent Photos Tom Chambers Federal Aviation A&n 4easernbled less happens istration nut out recoin- old chrttit sct lying around mended mode limit 400 expensive pat t1i ThThro ipt aircraft allow reachqailibt feet Koon became ob- can purchased chemical rium tfrt4uundiflg airA tern viousand still isthat ratus supplier foIl wing parts perature barograph should no idea high interes ml icropi t graduated same ambient air out sun therefore help make altitude 1/100 m1ii s 1-- 0 mtvilupetric other heat source visible settle arguments flash glass iil r dj thewiier level can ilso very useful know sure plastic glass ~Lsh rt lengths Ty- micro pipe o arest 1/100 ml altitude looks like terms gon tubing l0 Ins e diameter tubing read altitude chart Fig 3 riodel field typical flying metal This will give actual altitude reached altimeter described can very Before proce irg ith assembly above launch site altitude such purposes can also barometer t g t works launch site added above ground fpla/water attempts RC Helicopter rec- Note diagr ig Flask should altitude arrive absolute altitude above Hut dont look help RC almost full may mean sea level ower records conventional aircraft colored fqod dye easier reading theory behind barograph dithat record well over 20000 feet How- Flask B cont irs r apparatus rectly related Charles Boyles gas ever RC glider altitude record with- assembled tl4tt tip pipet laws ie volume gas case range altimeterit calibrated within 1/8 ~mjthe bottom Flask air varies indirectly pressure sur 6000 feet current world record After asse $1 barograph per rounding gas atmosphere directly 4988 feet Fig 1 sec side aircraft up- temperature gas Calcula Due weight size recording right posit o possible pro- tions graph Fig 3 have taken barographs altimeters almost ceed with Flight maneuvers such temperature consideration based impossible establish alt itud ion t ht stunts should average 10C temp decrease for model aircraft m4ans-Reor4-vio otto invert barograph 500 feet increase altitude baro ing barographs also expeve in- avq%ft lity air escaping metric values altitude taken strument described simpfe t rike Flk $ ced out tables standard atmospheric pressures calibrate accurate within plus ease altit After case interested dif minus 50 feet weighs less 5 altitucPdt61t h rnidreturn ferential pressures actual barometric ounces will fit miniature air- aircraft ground again avoiding pressure does have known craft cost less $500 can adverse maneuvers Remove barograph actually works apparatus assembled Flask B pipet contain water small amount pipet due capillary action model ascends air Flask B expands due lower outside pres sure higher elevation Air escapes through pipet atmosphere cannot get back Flask B due water seal As aircraft goes up air escapes However note Flask B always contains exact volume air case 10 ml can volume long necessary calculations made adjust difference 10 ml actual volume Flask B including measuring pipet calculated weighing empty flask pipet combination shown Fig 2 Fill water exactly top pipet weigh weight flask plus water minus weight empty flask grams me ml very highest altitude reached Flask B contains 10 ml reduced atmos pheric pressure depending altitude As aircraft descends atmospheric 26 Model Aviation components before assembly Left Flask B 10 ml Right Flask 26 ml flask shown 10 ml works just well foreground Micro Pipet center two pieces plastic tubing small vent tube Due size weight ordinary barographs altimeters has almost impossible establish altitude verification 777 FILL TO HERE _______ WITH WATER 1OML VOL FLASK B ________ MICRO ___________ PIPET P LAST C TUBING 020 STEEL ifTUBING WATER FLASK B Lii~ FLASK 1A FIGURE IFIGURE II pressure increases outside flask forces water up micro pipet maintain equilibrium between air pressure inside Flask B atmospheric pressure Simultaneously aircraft climbed higher air Flask B decreased temperature due upper air being cooler contraction air Flask B occurred As aircraft descends air Flask B expands slightly due increase tem perature Allowing flask equilibriate ambient air permits calculations temperature effect utilize stan dard 10C per 500 feet lapse rate altitude Increases decreases effect tem perature minor taken account calculating values Fig 3 following formula used cal culating graph Fig 3 VT2P V2 volume air B after de scent V me air B altitude 10 ml lute temperature* altitude lapse rate 10C/500 feet T2 olute temperature* ground level P mperature must 0Kelvin 273 al temp 0C atmospheric pressures must mm mercury atmospheric pressure* altitude std charts P2 spheric pressure* ground level 760mm arrive difference volume air B actual volume V formula subtracted volume B 10 ml get reading 100 feet altitude barometer can read near est 50 feet accurate 100 feet graph Fig 3 usable ground elevations 0 1000 feet should recalculated higher elevations plus minus 50 feet accuracy maintained So have gang Assemble go out set some altitude records settle club disputes high can fly aircraft chart calcu lated 6000 feet due orientation problems naked eye binocu lars additional aids altitude aircraft could still controlled ground could increased experience anything above 3000 feet very difficult control visual aids club members have tried barograph have enjoyed makes interesting afternoon get together altitude attempts amazing far off guessers can January 1976 27 Above Assembled unit ready use Flask bottom contains 15 ml colored water Flask B top inverted contains air Right Unit after flight Liquid level has risen Pipet Volume liquid determines alti tude Read directly chart 10 ml volume Flask B ALTITUDE CHART Flask B l Volume V me Water PipeS AItitde is feet ubove lsech Site VAltitudeVAltitude 031 00873100 06200903200 09300933300 12400963400 14500983500 176001013600 202001 043700 238001 063800 269001 093900 2910001124000 3211001t44100 3512001174200 3713001204300 4014001224400 4315001254500 4616001384600 4917001304700 5218001334800 5419001364900 5720001385000 6021001415100 6322001 435200 6623001465300 6524001 495400 7125001515500 7426001545600 7727001565700 7929001 595800 8229001 525900 8530001 646000 FIGURE III RAT RACING has evolved good beginners event probably competitive control-line event its 20 some years existence old days form aircraft acceptable long would take off land winner usually could successfully restart engine couple times race things have changed recent years state-of-the-art has up graded both through technological im provements engines also flying techniques improvements have proven demise event Participation especially new people practically non-existent feel lack participation new blood directly attributable two areas lack available information lack pilots intent article make available potential new comer details get started event Hooptee MK III Model presented article typical modern rat racers represents third basic design change have made rat racer designs past 12 years have using design three years has such consistent performer other top competitors Midwest area now using also include Bill Allen John Ballard Gary Fentress Bob Finely Pat Flinn quite easy construct once have gone through exercise time two first time through may scare bit due un usual construction technique namely fiberglass top future models will become quite easy confidence improves HOOPTE*B MKIIL updde c ro racing John F Kilsdonk first step select engine As writing HP-40 RRV engine popular However enough work being put OS-405R some day should least rank equal better HP Other 40-size engines avail able however passes both qualities absolutely necessary good rat engine high performance fast re start capability Whatever engine select start should fitted Midwest former ly Harters pinto speed pan can obtained through good hobby shop pan will require some grinding mount engine modifications pan should kept minimum structually weaken engine mounted using 4-40 X s requires drilling tapping pan after locating engine next step install landing gear single wheel landing gear shown plans has proven very popular because its ease installation extreme durability An 1/8 hole drilled through inboard side dimple location pan Another /8 hole drilled approximately 1 rear wing mounting boss pan Select 15 18 length of/g piano wire make two right angle bends same plane approximately middle piece center distance bends should correspond exactly center distance two landing gear holes Both holes drilled pan should radiused top accept radius piano wire bends Slip piano wire through two holes lightly tap place until well seated point Above Basic components prior assembly Below Finished wing engine/pen assembly fiberglass fuselage top has cut out match engine wing Leadout tubes covered basswood strips wing tip weight place its special cut-Out 28 Model Aviation