a yaw opposite direction result sluggish skidding turn caused down aileron producing drag up aileron Ailerons sailplane can amazingly effective used conjunction rudder Low dihedral also greatly reduces bad effects turbulent air Turbulence can thought sudden change direction airstream striking sailplane change airstream direc tion has two components horizontal component vertical component change vertical component changes angle attack wing stab makes nose go up downan effect easily corrected elevator control change horizontal component airstream produces roll sailplane dihedral harmless yaw Mariha landing gusty air Mariha will come straight level other sailplanes being bounced about three-channel Stand-Off Scale sailplane thermal slope soaring MARIHA HAS somewhat unusual origin local flier full-sized sailplanes Fred Hewitt designed full-sized proto type Mariha high performance homebuilt model version Freds sail plane built see anything could learned about design before construc tion full-sized version complete Since model Mariha design has evolved high-performance RC model sailplane maintains appearance full-scale Mariha yet combines speed maneuverability slope glider light wing loading flat-land thermal soarer extended speed range accom plished almost completely eliminating dihedral reduces drag improves high speed stability plane can float along 15 mph working light lift Yet eight ounces ballast downtrim ship will tear up field 40mph order effectively control sailplane having little dihedral must equipped ailerons Ailerons coordi nated rudder full-flying stabilizer give Mariha degree control sec ond all-out aerobatic gliders maneuverability primary design goal Mariha Critics may argue increased speed maneuverability must paid increased sink rate true some extent yet good pilot speed will help him find lift sooner maneu verability will help him stay lift longer Rudder control alone enough steer sailplane having little no dihedral Rudder alone produces mild yaw Ailerons needed also ailerons alone produce bank direction David Andersen Photos George Otis Although Mariha designed primar ily slope soaring Midwest turned out competitive thermal hunter well because slopes Midwest rather small shallowfaced Slope soaring Midwest gener ally consists skimming close above crest bill until safe altitude reached striking out search thermals Thus sailplane requirements slope soaring hi-start flying Midwest dont differ very much Top Built testing purposes prior Construc tion full-scale homebuilt Mariha has natu rally graceful configuration Left author gets Mariha away winch tow Below beautiful flier Mariha has ability perform tight loops inverted flight split-S axial rolls has scale-like attributes 10 Model Aviation c7tarilfa During Twin City Radio Controllers fall glider contest Marihas pilot lured 14-minute thermal flight pair red-tailed hawks score longest flight contest Unfortunately task five-minute precision event flight received zero points Nevertheless Mariha went win third place spite pilots impetuous behavior Mariha design has evolved over last four years during two models four wings preceeded final design Hundreds flights weather terrain conditions have flown Yet because its responsiveness recommended beginner glider flying Some experience high perform ance sailplanes recommended before attempting fly Mariha Construction Wing The wing important part sailplane should con structed much precision possible Mariha has one-piece wing spans 105 wingspan arrived determining biggest possible span would fit inside 62 Ford Falcon Meas ure car before deciding build Wing construction rather conventional careful select wood equal density both sides wing important have little gap aileron hinge possible Any air gap will add drag reduce effectiveness Make leading edge aileron V-shaped its corresponding fixed surface flat hinge pin should centered apex N inset both sides hinge Cover mating surfaces aileron Solarfilm before gluing hinge place Cover rest wing later wing panels can built either flat board over plans wood scrap shims hold ribs equal incidence angles wing may built wingrod jig achieve correct dihedral angle pin center section down flat prop up outer wing panels inch rib W12 glue dries dihedral joints Use Goldberg aileron connector Left Hows accessibility Rudder ailerons coupledstab full-flying Top Rubberbands wing-mounting internal minimize damage Below Bands loop over fore aft dowels Spoilers required affix servo place double faced foam tape Add little washout after covering heating twisting wing tips tends soften stall October1976 11 Above Hoerner-type wing tips add efficiency Below unique feature detail hinging reducing tip vortices Overall design con rudder side pushrod showni trol set-up allows less dihedral other Note antenna protruding bottom Mariha Fuselage The wing strapped onto fuselage least six No 64 rubberbands Wing saddle tape should also used increase friction ancient time proven method has recently fallen disrepute because rubberbands show ugly However rubberbands completely inside fuselage well covered canopy event hard wingtip landing wing will knocked askew preventing damage plenty room inside fuse lage mount servos servo tray battery pack recessed noseblock receiver attached fuselage floor double-faced foam tape receiver should moved back forth fine-adjust center gravity should necessary add weight anywhere balance Mariha Total flying weight should 2 lb 8 oz ballast Stabilizer The all-flying stab well protected ground contact being mounted rather high fin Therefore single wooden dowel needed connect stabilizer halves fuse lage Build stab crank its plywood box separate assembly sure free moving before glueing fuse lage crutch Glue stab halves torque rod after both fuselage stab completed stab turns out perfectly parallel wing shim up side wing extra layer wing saddle tape Flying sure center gravity shown plans stabilizer incidence 00 shown plans rec ommended full down trim position hi-start launch set trim lever between mid down trim launch fastjavelin style Mariha likes fly little faster sailplanes settled tow move trim lever full up back mid trim release Steering tow done mostly rudder using ailerons hold wing level Mariha designed flown three channels first few flights perfectly permissible electrically couple ailerons rudder eases transition rudder-elevator flying habits Make Y-shaped aileron extension cable plug both aileron rudder servos same channel Flying three channels next step Remem ber rudder steers aileron banks move turn move aile rons rudder together start turn Once proper amount bank has established ease off ailerons give little up elevator little opposite rud der Extremely flat tight turns can made little loss altitude using rudder elevator hold nose up ailerons maintain banka big help working small bubble thermals Now come out turn move 4 -0 I III 0 o 0 0 0 ao aga I__________________________________ S 5 se \ S 0044 12 Model Aviation KO V I ooa0 jpap- Irir7 ~i// I-0Hj p U2H 0 aa. tpa IL 5: atO a0 F Ill 5 p = a pp pa aI/ Ias 1 5 I] I 0 a -4 Fh loom ItoH ma1 lOPE LI pa 0~ 0.~ a 5 0 zg 000 050 ao 000 00 0 a 0 ailerons rudder together nudge down elevator comes about wind practice down-wind turns can made safely low altitudes kinds turns very scale-like because exactly fullsized sailplanes flown Landings made just like full-sized sailplanes also may approach landing spot pattern approach downwind leg base leg final approach Since Mariha does have spoilers S-turns made final spill excess altitude Rudder can used cause extra side-slipping about 10 feet altitude left level off use just ailerons elevator Hard right rudder can used create extra drag speed little too high Hold wing level ailerons flare out scale touch down windy give full down elevator soon ship touches down will prevent ship flipping over should wing tip swing wind Its good idea try some stalls safe altitude youll know whats happen ing happen close ground Most sailplanes will roll side suddenly stalled Mariha pro duces yaw preceeded fishtailing effect give warning Now try loop Because close coupling Mariha can make small tight loops Large loops require little up elevator Al though Mariha designed aero batics split-s axial roll inverted flight possible dont try unless can maneuvers well powered airplanes first windy weather best fly ballast Cut pocket block foam rubber drop about 8 oz lead curtain weights pocket secure rubberband stuff foam rubber ballast bag under wing between bulk heads F3 F4 will bring wing loading up about 10 oz/sq ft Mariha has often mistaken full-sized sailplane circling overhead indicative its scale-like appearance its scale-like flying performance well slope soaring strong lift load up much ballast down trim lift conditions will permit Too much down trim will make elevator too sen sitive warning using too much down trimbetter add ballast speed instead Fly far up upwind side slope move out away slope Now make sharp turn down wind pushing stick forward diving downwind pointing nose ship directly toward Mariha will pick up speed quickly come silently screaming toward like ghost Captain Mid night Gently pull up bank away hill Mariha sails overhead 40 50 mph Pull nose straight up full rudder little aileron rotate around big airshow turn Beautiful Once youve seen youll never forget October1976 13
Edition: Model Aviation - 1976/10
Page Numbers: 10, 11, 12, 13
a yaw opposite direction result sluggish skidding turn caused down aileron producing drag up aileron Ailerons sailplane can amazingly effective used conjunction rudder Low dihedral also greatly reduces bad effects turbulent air Turbulence can thought sudden change direction airstream striking sailplane change airstream direc tion has two components horizontal component vertical component change vertical component changes angle attack wing stab makes nose go up downan effect easily corrected elevator control change horizontal component airstream produces roll sailplane dihedral harmless yaw Mariha landing gusty air Mariha will come straight level other sailplanes being bounced about three-channel Stand-Off Scale sailplane thermal slope soaring MARIHA HAS somewhat unusual origin local flier full-sized sailplanes Fred Hewitt designed full-sized proto type Mariha high performance homebuilt model version Freds sail plane built see anything could learned about design before construc tion full-sized version complete Since model Mariha design has evolved high-performance RC model sailplane maintains appearance full-scale Mariha yet combines speed maneuverability slope glider light wing loading flat-land thermal soarer extended speed range accom plished almost completely eliminating dihedral reduces drag improves high speed stability plane can float along 15 mph working light lift Yet eight ounces ballast downtrim ship will tear up field 40mph order effectively control sailplane having little dihedral must equipped ailerons Ailerons coordi nated rudder full-flying stabilizer give Mariha degree control sec ond all-out aerobatic gliders maneuverability primary design goal Mariha Critics may argue increased speed maneuverability must paid increased sink rate true some extent yet good pilot speed will help him find lift sooner maneu verability will help him stay lift longer Rudder control alone enough steer sailplane having little no dihedral Rudder alone produces mild yaw Ailerons needed also ailerons alone produce bank direction David Andersen Photos George Otis Although Mariha designed primar ily slope soaring Midwest turned out competitive thermal hunter well because slopes Midwest rather small shallowfaced Slope soaring Midwest gener ally consists skimming close above crest bill until safe altitude reached striking out search thermals Thus sailplane requirements slope soaring hi-start flying Midwest dont differ very much Top Built testing purposes prior Construc tion full-scale homebuilt Mariha has natu rally graceful configuration Left author gets Mariha away winch tow Below beautiful flier Mariha has ability perform tight loops inverted flight split-S axial rolls has scale-like attributes 10 Model Aviation c7tarilfa During Twin City Radio Controllers fall glider contest Marihas pilot lured 14-minute thermal flight pair red-tailed hawks score longest flight contest Unfortunately task five-minute precision event flight received zero points Nevertheless Mariha went win third place spite pilots impetuous behavior Mariha design has evolved over last four years during two models four wings preceeded final design Hundreds flights weather terrain conditions have flown Yet because its responsiveness recommended beginner glider flying Some experience high perform ance sailplanes recommended before attempting fly Mariha Construction Wing The wing important part sailplane should con structed much precision possible Mariha has one-piece wing spans 105 wingspan arrived determining biggest possible span would fit inside 62 Ford Falcon Meas ure car before deciding build Wing construction rather conventional careful select wood equal density both sides wing important have little gap aileron hinge possible Any air gap will add drag reduce effectiveness Make leading edge aileron V-shaped its corresponding fixed surface flat hinge pin should centered apex N inset both sides hinge Cover mating surfaces aileron Solarfilm before gluing hinge place Cover rest wing later wing panels can built either flat board over plans wood scrap shims hold ribs equal incidence angles wing may built wingrod jig achieve correct dihedral angle pin center section down flat prop up outer wing panels inch rib W12 glue dries dihedral joints Use Goldberg aileron connector Left Hows accessibility Rudder ailerons coupledstab full-flying Top Rubberbands wing-mounting internal minimize damage Below Bands loop over fore aft dowels Spoilers required affix servo place double faced foam tape Add little washout after covering heating twisting wing tips tends soften stall October1976 11 Above Hoerner-type wing tips add efficiency Below unique feature detail hinging reducing tip vortices Overall design con rudder side pushrod showni trol set-up allows less dihedral other Note antenna protruding bottom Mariha Fuselage The wing strapped onto fuselage least six No 64 rubberbands Wing saddle tape should also used increase friction ancient time proven method has recently fallen disrepute because rubberbands show ugly However rubberbands completely inside fuselage well covered canopy event hard wingtip landing wing will knocked askew preventing damage plenty room inside fuse lage mount servos servo tray battery pack recessed noseblock receiver attached fuselage floor double-faced foam tape receiver should moved back forth fine-adjust center gravity should necessary add weight anywhere balance Mariha Total flying weight should 2 lb 8 oz ballast Stabilizer The all-flying stab well protected ground contact being mounted rather high fin Therefore single wooden dowel needed connect stabilizer halves fuse lage Build stab crank its plywood box separate assembly sure free moving before glueing fuse lage crutch Glue stab halves torque rod after both fuselage stab completed stab turns out perfectly parallel wing shim up side wing extra layer wing saddle tape Flying sure center gravity shown plans stabilizer incidence 00 shown plans rec ommended full down trim position hi-start launch set trim lever between mid down trim launch fastjavelin style Mariha likes fly little faster sailplanes settled tow move trim lever full up back mid trim release Steering tow done mostly rudder using ailerons hold wing level Mariha designed flown three channels first few flights perfectly permissible electrically couple ailerons rudder eases transition rudder-elevator flying habits Make Y-shaped aileron extension cable plug both aileron rudder servos same channel Flying three channels next step Remem ber rudder steers aileron banks move turn move aile rons rudder together start turn Once proper amount bank has established ease off ailerons give little up elevator little opposite rud der Extremely flat tight turns can made little loss altitude using rudder elevator hold nose up ailerons maintain banka big help working small bubble thermals Now come out turn move 4 -0 I III 0 o 0 0 0 ao aga I__________________________________ S 5 se \ S 0044 12 Model Aviation KO V I ooa0 jpap- Irir7 ~i// I-0Hj p U2H 0 aa. tpa IL 5: atO a0 F Ill 5 p = a pp pa aI/ Ias 1 5 I] I 0 a -4 Fh loom ItoH ma1 lOPE LI pa 0~ 0.~ a 5 0 zg 000 050 ao 000 00 0 a 0 ailerons rudder together nudge down elevator comes about wind practice down-wind turns can made safely low altitudes kinds turns very scale-like because exactly fullsized sailplanes flown Landings made just like full-sized sailplanes also may approach landing spot pattern approach downwind leg base leg final approach Since Mariha does have spoilers S-turns made final spill excess altitude Rudder can used cause extra side-slipping about 10 feet altitude left level off use just ailerons elevator Hard right rudder can used create extra drag speed little too high Hold wing level ailerons flare out scale touch down windy give full down elevator soon ship touches down will prevent ship flipping over should wing tip swing wind Its good idea try some stalls safe altitude youll know whats happen ing happen close ground Most sailplanes will roll side suddenly stalled Mariha pro duces yaw preceeded fishtailing effect give warning Now try loop Because close coupling Mariha can make small tight loops Large loops require little up elevator Al though Mariha designed aero batics split-s axial roll inverted flight possible dont try unless can maneuvers well powered airplanes first windy weather best fly ballast Cut pocket block foam rubber drop about 8 oz lead curtain weights pocket secure rubberband stuff foam rubber ballast bag under wing between bulk heads F3 F4 will bring wing loading up about 10 oz/sq ft Mariha has often mistaken full-sized sailplane circling overhead indicative its scale-like appearance its scale-like flying performance well slope soaring strong lift load up much ballast down trim lift conditions will permit Too much down trim will make elevator too sen sitive warning using too much down trimbetter add ballast speed instead Fly far up upwind side slope move out away slope Now make sharp turn down wind pushing stick forward diving downwind pointing nose ship directly toward Mariha will pick up speed quickly come silently screaming toward like ghost Captain Mid night Gently pull up bank away hill Mariha sails overhead 40 50 mph Pull nose straight up full rudder little aileron rotate around big airshow turn Beautiful Once youve seen youll never forget October1976 13
Edition: Model Aviation - 1976/10
Page Numbers: 10, 11, 12, 13
a yaw opposite direction result sluggish skidding turn caused down aileron producing drag up aileron Ailerons sailplane can amazingly effective used conjunction rudder Low dihedral also greatly reduces bad effects turbulent air Turbulence can thought sudden change direction airstream striking sailplane change airstream direc tion has two components horizontal component vertical component change vertical component changes angle attack wing stab makes nose go up downan effect easily corrected elevator control change horizontal component airstream produces roll sailplane dihedral harmless yaw Mariha landing gusty air Mariha will come straight level other sailplanes being bounced about three-channel Stand-Off Scale sailplane thermal slope soaring MARIHA HAS somewhat unusual origin local flier full-sized sailplanes Fred Hewitt designed full-sized proto type Mariha high performance homebuilt model version Freds sail plane built see anything could learned about design before construc tion full-sized version complete Since model Mariha design has evolved high-performance RC model sailplane maintains appearance full-scale Mariha yet combines speed maneuverability slope glider light wing loading flat-land thermal soarer extended speed range accom plished almost completely eliminating dihedral reduces drag improves high speed stability plane can float along 15 mph working light lift Yet eight ounces ballast downtrim ship will tear up field 40mph order effectively control sailplane having little dihedral must equipped ailerons Ailerons coordi nated rudder full-flying stabilizer give Mariha degree control sec ond all-out aerobatic gliders maneuverability primary design goal Mariha Critics may argue increased speed maneuverability must paid increased sink rate true some extent yet good pilot speed will help him find lift sooner maneu verability will help him stay lift longer Rudder control alone enough steer sailplane having little no dihedral Rudder alone produces mild yaw Ailerons needed also ailerons alone produce bank direction David Andersen Photos George Otis Although Mariha designed primar ily slope soaring Midwest turned out competitive thermal hunter well because slopes Midwest rather small shallowfaced Slope soaring Midwest gener ally consists skimming close above crest bill until safe altitude reached striking out search thermals Thus sailplane requirements slope soaring hi-start flying Midwest dont differ very much Top Built testing purposes prior Construc tion full-scale homebuilt Mariha has natu rally graceful configuration Left author gets Mariha away winch tow Below beautiful flier Mariha has ability perform tight loops inverted flight split-S axial rolls has scale-like attributes 10 Model Aviation c7tarilfa During Twin City Radio Controllers fall glider contest Marihas pilot lured 14-minute thermal flight pair red-tailed hawks score longest flight contest Unfortunately task five-minute precision event flight received zero points Nevertheless Mariha went win third place spite pilots impetuous behavior Mariha design has evolved over last four years during two models four wings preceeded final design Hundreds flights weather terrain conditions have flown Yet because its responsiveness recommended beginner glider flying Some experience high perform ance sailplanes recommended before attempting fly Mariha Construction Wing The wing important part sailplane should con structed much precision possible Mariha has one-piece wing spans 105 wingspan arrived determining biggest possible span would fit inside 62 Ford Falcon Meas ure car before deciding build Wing construction rather conventional careful select wood equal density both sides wing important have little gap aileron hinge possible Any air gap will add drag reduce effectiveness Make leading edge aileron V-shaped its corresponding fixed surface flat hinge pin should centered apex N inset both sides hinge Cover mating surfaces aileron Solarfilm before gluing hinge place Cover rest wing later wing panels can built either flat board over plans wood scrap shims hold ribs equal incidence angles wing may built wingrod jig achieve correct dihedral angle pin center section down flat prop up outer wing panels inch rib W12 glue dries dihedral joints Use Goldberg aileron connector Left Hows accessibility Rudder ailerons coupledstab full-flying Top Rubberbands wing-mounting internal minimize damage Below Bands loop over fore aft dowels Spoilers required affix servo place double faced foam tape Add little washout after covering heating twisting wing tips tends soften stall October1976 11 Above Hoerner-type wing tips add efficiency Below unique feature detail hinging reducing tip vortices Overall design con rudder side pushrod showni trol set-up allows less dihedral other Note antenna protruding bottom Mariha Fuselage The wing strapped onto fuselage least six No 64 rubberbands Wing saddle tape should also used increase friction ancient time proven method has recently fallen disrepute because rubberbands show ugly However rubberbands completely inside fuselage well covered canopy event hard wingtip landing wing will knocked askew preventing damage plenty room inside fuse lage mount servos servo tray battery pack recessed noseblock receiver attached fuselage floor double-faced foam tape receiver should moved back forth fine-adjust center gravity should necessary add weight anywhere balance Mariha Total flying weight should 2 lb 8 oz ballast Stabilizer The all-flying stab well protected ground contact being mounted rather high fin Therefore single wooden dowel needed connect stabilizer halves fuse lage Build stab crank its plywood box separate assembly sure free moving before glueing fuse lage crutch Glue stab halves torque rod after both fuselage stab completed stab turns out perfectly parallel wing shim up side wing extra layer wing saddle tape Flying sure center gravity shown plans stabilizer incidence 00 shown plans rec ommended full down trim position hi-start launch set trim lever between mid down trim launch fastjavelin style Mariha likes fly little faster sailplanes settled tow move trim lever full up back mid trim release Steering tow done mostly rudder using ailerons hold wing level Mariha designed flown three channels first few flights perfectly permissible electrically couple ailerons rudder eases transition rudder-elevator flying habits Make Y-shaped aileron extension cable plug both aileron rudder servos same channel Flying three channels next step Remem ber rudder steers aileron banks move turn move aile rons rudder together start turn Once proper amount bank has established ease off ailerons give little up elevator little opposite rud der Extremely flat tight turns can made little loss altitude using rudder elevator hold nose up ailerons maintain banka big help working small bubble thermals Now come out turn move 4 -0 I III 0 o 0 0 0 ao aga I__________________________________ S 5 se \ S 0044 12 Model Aviation KO V I ooa0 jpap- Irir7 ~i// I-0Hj p U2H 0 aa. tpa IL 5: atO a0 F Ill 5 p = a pp pa aI/ Ias 1 5 I] I 0 a -4 Fh loom ItoH ma1 lOPE LI pa 0~ 0.~ a 5 0 zg 000 050 ao 000 00 0 a 0 ailerons rudder together nudge down elevator comes about wind practice down-wind turns can made safely low altitudes kinds turns very scale-like because exactly fullsized sailplanes flown Landings made just like full-sized sailplanes also may approach landing spot pattern approach downwind leg base leg final approach Since Mariha does have spoilers S-turns made final spill excess altitude Rudder can used cause extra side-slipping about 10 feet altitude left level off use just ailerons elevator Hard right rudder can used create extra drag speed little too high Hold wing level ailerons flare out scale touch down windy give full down elevator soon ship touches down will prevent ship flipping over should wing tip swing wind Its good idea try some stalls safe altitude youll know whats happen ing happen close ground Most sailplanes will roll side suddenly stalled Mariha pro duces yaw preceeded fishtailing effect give warning Now try loop Because close coupling Mariha can make small tight loops Large loops require little up elevator Al though Mariha designed aero batics split-s axial roll inverted flight possible dont try unless can maneuvers well powered airplanes first windy weather best fly ballast Cut pocket block foam rubber drop about 8 oz lead curtain weights pocket secure rubberband stuff foam rubber ballast bag under wing between bulk heads F3 F4 will bring wing loading up about 10 oz/sq ft Mariha has often mistaken full-sized sailplane circling overhead indicative its scale-like appearance its scale-like flying performance well slope soaring strong lift load up much ballast down trim lift conditions will permit Too much down trim will make elevator too sen sitive warning using too much down trimbetter add ballast speed instead Fly far up upwind side slope move out away slope Now make sharp turn down wind pushing stick forward diving downwind pointing nose ship directly toward Mariha will pick up speed quickly come silently screaming toward like ghost Captain Mid night Gently pull up bank away hill Mariha sails overhead 40 50 mph Pull nose straight up full rudder little aileron rotate around big airshow turn Beautiful Once youve seen youll never forget October1976 13
Edition: Model Aviation - 1976/10
Page Numbers: 10, 11, 12, 13
a yaw opposite direction result sluggish skidding turn caused down aileron producing drag up aileron Ailerons sailplane can amazingly effective used conjunction rudder Low dihedral also greatly reduces bad effects turbulent air Turbulence can thought sudden change direction airstream striking sailplane change airstream direc tion has two components horizontal component vertical component change vertical component changes angle attack wing stab makes nose go up downan effect easily corrected elevator control change horizontal component airstream produces roll sailplane dihedral harmless yaw Mariha landing gusty air Mariha will come straight level other sailplanes being bounced about three-channel Stand-Off Scale sailplane thermal slope soaring MARIHA HAS somewhat unusual origin local flier full-sized sailplanes Fred Hewitt designed full-sized proto type Mariha high performance homebuilt model version Freds sail plane built see anything could learned about design before construc tion full-sized version complete Since model Mariha design has evolved high-performance RC model sailplane maintains appearance full-scale Mariha yet combines speed maneuverability slope glider light wing loading flat-land thermal soarer extended speed range accom plished almost completely eliminating dihedral reduces drag improves high speed stability plane can float along 15 mph working light lift Yet eight ounces ballast downtrim ship will tear up field 40mph order effectively control sailplane having little dihedral must equipped ailerons Ailerons coordi nated rudder full-flying stabilizer give Mariha degree control sec ond all-out aerobatic gliders maneuverability primary design goal Mariha Critics may argue increased speed maneuverability must paid increased sink rate true some extent yet good pilot speed will help him find lift sooner maneu verability will help him stay lift longer Rudder control alone enough steer sailplane having little no dihedral Rudder alone produces mild yaw Ailerons needed also ailerons alone produce bank direction David Andersen Photos George Otis Although Mariha designed primar ily slope soaring Midwest turned out competitive thermal hunter well because slopes Midwest rather small shallowfaced Slope soaring Midwest gener ally consists skimming close above crest bill until safe altitude reached striking out search thermals Thus sailplane requirements slope soaring hi-start flying Midwest dont differ very much Top Built testing purposes prior Construc tion full-scale homebuilt Mariha has natu rally graceful configuration Left author gets Mariha away winch tow Below beautiful flier Mariha has ability perform tight loops inverted flight split-S axial rolls has scale-like attributes 10 Model Aviation c7tarilfa During Twin City Radio Controllers fall glider contest Marihas pilot lured 14-minute thermal flight pair red-tailed hawks score longest flight contest Unfortunately task five-minute precision event flight received zero points Nevertheless Mariha went win third place spite pilots impetuous behavior Mariha design has evolved over last four years during two models four wings preceeded final design Hundreds flights weather terrain conditions have flown Yet because its responsiveness recommended beginner glider flying Some experience high perform ance sailplanes recommended before attempting fly Mariha Construction Wing The wing important part sailplane should con structed much precision possible Mariha has one-piece wing spans 105 wingspan arrived determining biggest possible span would fit inside 62 Ford Falcon Meas ure car before deciding build Wing construction rather conventional careful select wood equal density both sides wing important have little gap aileron hinge possible Any air gap will add drag reduce effectiveness Make leading edge aileron V-shaped its corresponding fixed surface flat hinge pin should centered apex N inset both sides hinge Cover mating surfaces aileron Solarfilm before gluing hinge place Cover rest wing later wing panels can built either flat board over plans wood scrap shims hold ribs equal incidence angles wing may built wingrod jig achieve correct dihedral angle pin center section down flat prop up outer wing panels inch rib W12 glue dries dihedral joints Use Goldberg aileron connector Left Hows accessibility Rudder ailerons coupledstab full-flying Top Rubberbands wing-mounting internal minimize damage Below Bands loop over fore aft dowels Spoilers required affix servo place double faced foam tape Add little washout after covering heating twisting wing tips tends soften stall October1976 11 Above Hoerner-type wing tips add efficiency Below unique feature detail hinging reducing tip vortices Overall design con rudder side pushrod showni trol set-up allows less dihedral other Note antenna protruding bottom Mariha Fuselage The wing strapped onto fuselage least six No 64 rubberbands Wing saddle tape should also used increase friction ancient time proven method has recently fallen disrepute because rubberbands show ugly However rubberbands completely inside fuselage well covered canopy event hard wingtip landing wing will knocked askew preventing damage plenty room inside fuse lage mount servos servo tray battery pack recessed noseblock receiver attached fuselage floor double-faced foam tape receiver should moved back forth fine-adjust center gravity should necessary add weight anywhere balance Mariha Total flying weight should 2 lb 8 oz ballast Stabilizer The all-flying stab well protected ground contact being mounted rather high fin Therefore single wooden dowel needed connect stabilizer halves fuse lage Build stab crank its plywood box separate assembly sure free moving before glueing fuse lage crutch Glue stab halves torque rod after both fuselage stab completed stab turns out perfectly parallel wing shim up side wing extra layer wing saddle tape Flying sure center gravity shown plans stabilizer incidence 00 shown plans rec ommended full down trim position hi-start launch set trim lever between mid down trim launch fastjavelin style Mariha likes fly little faster sailplanes settled tow move trim lever full up back mid trim release Steering tow done mostly rudder using ailerons hold wing level Mariha designed flown three channels first few flights perfectly permissible electrically couple ailerons rudder eases transition rudder-elevator flying habits Make Y-shaped aileron extension cable plug both aileron rudder servos same channel Flying three channels next step Remem ber rudder steers aileron banks move turn move aile rons rudder together start turn Once proper amount bank has established ease off ailerons give little up elevator little opposite rud der Extremely flat tight turns can made little loss altitude using rudder elevator hold nose up ailerons maintain banka big help working small bubble thermals Now come out turn move 4 -0 I III 0 o 0 0 0 ao aga I__________________________________ S 5 se \ S 0044 12 Model Aviation KO V I ooa0 jpap- Irir7 ~i// I-0Hj p U2H 0 aa. tpa IL 5: atO a0 F Ill 5 p = a pp pa aI/ Ias 1 5 I] I 0 a -4 Fh loom ItoH ma1 lOPE LI pa 0~ 0.~ a 5 0 zg 000 050 ao 000 00 0 a 0 ailerons rudder together nudge down elevator comes about wind practice down-wind turns can made safely low altitudes kinds turns very scale-like because exactly fullsized sailplanes flown Landings made just like full-sized sailplanes also may approach landing spot pattern approach downwind leg base leg final approach Since Mariha does have spoilers S-turns made final spill excess altitude Rudder can used cause extra side-slipping about 10 feet altitude left level off use just ailerons elevator Hard right rudder can used create extra drag speed little too high Hold wing level ailerons flare out scale touch down windy give full down elevator soon ship touches down will prevent ship flipping over should wing tip swing wind Its good idea try some stalls safe altitude youll know whats happen ing happen close ground Most sailplanes will roll side suddenly stalled Mariha pro duces yaw preceeded fishtailing effect give warning Now try loop Because close coupling Mariha can make small tight loops Large loops require little up elevator Al though Mariha designed aero batics split-s axial roll inverted flight possible dont try unless can maneuvers well powered airplanes first windy weather best fly ballast Cut pocket block foam rubber drop about 8 oz lead curtain weights pocket secure rubberband stuff foam rubber ballast bag under wing between bulk heads F3 F4 will bring wing loading up about 10 oz/sq ft Mariha has often mistaken full-sized sailplane circling overhead indicative its scale-like appearance its scale-like flying performance well slope soaring strong lift load up much ballast down trim lift conditions will permit Too much down trim will make elevator too sen sitive warning using too much down trimbetter add ballast speed instead Fly far up upwind side slope move out away slope Now make sharp turn down wind pushing stick forward diving downwind pointing nose ship directly toward Mariha will pick up speed quickly come silently screaming toward like ghost Captain Mid night Gently pull up bank away hill Mariha sails overhead 40 50 mph Pull nose straight up full rudder little aileron rotate around big airshow turn Beautiful Once youve seen youll never forget October1976 13