Curtiss SOC-1 Seagull

NO OCR TEXT NO OCR TEXT p cabane struts cut 1/a-in sheet aluminum using either band jigsaw method theres no welding soldering 160 ft 10-knot headwind have read original test pilot reports reveal Seagulls flight characteristics Open wheel pants typical Navy air planes 1930s large wheels smooth out grass-field landings takeoffs found very good general excel lent water handling pre-radar days scout planes like Smooth steady Seagull makes Ideal subject large-scale model Take offs landings easy due correct landing gear position overall stability pilot looked through tubular gun sight aim 30 calIber Browning machine gun Most planes lightly armed prior WW II lower wing has generous ailerons Unusually large tail surfaces help make mounting studs interplane struts make Seagull stable solid model Navy pilots assembly quick allow precise adjustment praised flying characteristics plane 26 Model Aviation Graceful curves set mis moaei apart form usual crowd IMAA fly-in Power can available gasoline engines Quadra 40 Zenoah 38 best suited -j small ailerons inc top wing allowed room large flaps Leading trailing edge flaps outlined black tape CURTISS sod Paurum flRSONS Q PIBRGLRS 2 1 S-czr R PLANK - II ASHTEAL SMUT 24 DIR M1L/6x4 srn~ A8RLR 8ET X &1T TRINGR OURL LAIVilNATED 3 HT BRLAj Y* BAL5A 3 RIBS 5DJ /HELS BLOCK Jx1 T &OCK N BALSA LPMINRTo QPRUCZ & BRLeR PRR5 BflLR iT -7/ k ~ PRUc \ I 1 ALUM 5TRRMLIJZ TVB INS TE STOCK Seagull served eyes fleet big cannons Navy using range farther eye could see came Seagulls primary tasks fly over target area radio back infor mation used adjust na val gunfire could also attack small tar gets its two 30-caliber machine guns two 100-lb bombs though later stan dards its armament would considered significant Seagulls Pratt Whitney Wasp en gine R-1340 must best ever built used fighters before Sea gull later trainers can see today SNJ/AT-6 Texans Now-a-days theyve improved produce 600 hp the Seagull rated 550 hp remarkable thing about Sea gull its long service life era airplanes changing fast its out standing flight characteristics its toughness dependability biplane managed remain active whole WW 11 fact its replacement midwing mono plane Seagull 11another Curtiss design proved real turkey rejected features make Seagull fine Giant Scale project among large tail surfaces simple landing gear fabric covering simple grace ful lines plans follow full-scale out line no deviations scale Scale rib stringer spacing maintained areas full-size aircraft fabric metal reproduced fabric fibergiassed wood respec tively extent fine detailing left discretion the individual builder Another nice thing about model youre almost guaranteed able take contest knowing everybody else brother wont have model very docile flight lands slowly two degrees right thrust big fin rudder takeoffs very very easy No tip stall tendencies snap rolls have noted Construction somewhat complex lengthy fly ing will pose no problems airplane ideal initiation Giant Scale plans designed experi 3/16 SO BERIJCE3/16 SQ SPRUCE STRINGERS STRINGEHOI/H tIlE PLYNOT SHOWN UN SlOE VIEWVB Pt 1/8 PLYWOOD 2T ___BALSA LE 3ATI/O PLY I/8LITE PLY51MOUNT I/H LITE 6T8M K 4TSTA1/8 BALSA CSHEDYFRAME~3TK I/H H OLGA I/B BALSA125 ALUMINUMSPRU LITE PLY PLANKINGCABUNE STHJTc. BULSA 2 ALUM ANGLE FOR COWL ATTACBPLANKINGSPARS 3AT ST SOFT BALSA PAIRINGST BLOCK ST COWL AVAILABLE FIBERGLASS MASTER ____ 5IJBOS 5303/B BALSA/BALSA SHEET FUEL TANK ARETHIS PT WITH 1/4 BAtS SHEET-SHAPE I/A AIR SUCTI/H BALSACONTOUR ROOFGUSSETSW VB LITE PLYI -GAI/4BA -GREETSOLRLER I/H LITE PLY JG-IERI 3UI I/B BALSA/ PLANKING-NOTGAII1/4 PLY WINS SHOWN FOR CLARITYATTACH PIECE FG-IVOLE 3/IN SURAL -FG2WING FAIRINGLANSING GEAR SEE TEST 1/8 LI/K PLY 2U I5 SIA MAIN WHEELSA UHLITE PLY I/H LITE PLY U2 d AIR~IRONI/2uh1ALSA K177 OGETWHEEL PART BUILT UP 3AUOPENINGSHEETRU1/8 LITE I/H LITEPLYPLY enced builder Its recommended pat terns traced plans onto See Temp plastic sheeting available PO Box 105 Sussex WI 53089 Use See Temp templates guide cut out parts check against plans accuracy Using Dremel saw sander found after tracing parts onto wood could cut out evening Wing plans should lightly coated Johnsons baby oil turned over left panels None us has ever built two right-hand panels per wing have Left The author checks basic fuselage box squareness Seagull can build directly work table resorting timeconsuming jigs Right Bulkheads stringers added basic box still pinned work table ensuring no warps later 28 Model Aviation Full-Size Plans Available Page 196 I/A PLYWOSSI/B LITE PLY3/16 BALSA SHEET I/R LITE PLY ________RUDDER LEI/3BALSA SHEET I/B BALSA SHEET_____________________ NI/H BALSA SHEET __SalI __2Fl ___lOTlITF-Z WING DOUBLER F-3 /4 BALSA BALSA SHEET F-4 TYP FIB RIB IfA LITE PLYRI 3/16 SO SPRUCEOR BALSA SHEET ESTASBZSTRINGERS 6-32 ID TYP ATI/A PLY REAR MOUNT AT AT- CABANE PATTERNfi BY HAlI/4 BALSA L EPH NI ItHAS //3/16SG SPRUCE STRO BO/32 BALSA/ ///91I/B BALSA SHEETINGFALSE LEFIN 9B2NOT SHOWN FOR CLARITY /IIII_______ ~TPARSONS FIBERGLASS ji RHI RUCEN TRINGER S STRNGER VB BALSA STRINGER N 1/BRALGA ILL IN THIS PANEL A/STRINGERS AR/ 1TSTRINGER BI/B BALSA SHEETPUSHNOSS AREI IIIHEAVY BUTT CLEVIS BOTTOM LONGERON j SOOBLES FROM THIS BALSA SHEET POINT AFT WITH BALSA BALSA SHEET SHEET OF 3 FUSELAGESIDE VIEW 2UBI/B LITESPECIFICATIONSSHOWN FORUSE 5/32 NOSE GEARMODEL AVIATION PLYSCALE ll/S SCALECLARITYMOUNT FOR TAILWHEEL TYGORHENT CURTISS SEAGULL TEWING SPAN90 WING AREA2200 50 IN U-I/2SLS TAILWHOELDESIGNED BY PAUL BYRUM STRINGERSWEISRT24 POUNSOos HETRACING BY JOE DERAARCO RUCEENGINEAURORA HO ORZENOGH ORI LL RIGHTS RESERVED word about materials used balsa lower wing fairings wheel pants Ply- item Fiberglass Master Rt 1 Box Hobby Woods 2931 Larkin Clovis CA wood spruce came Balsa USA 530 Goodview VA 24095 landing 93612 because available density Super Coverite recommended gear D&D Engineering 201 SE grades attractively priced Use Dan Parsons fiberglass method 12th St Pompano Beach FL 33080 medium-density wood applica- glass cloth itself wood surfaces Par- reference three-view Aviation tions lower density trailing edges sons 11809 Fulmer Drive NE Albu- News Ian Stair available Repla tips lowest density querque NM 87111 cowl stock Tech International 48500 McKenzie HighLeft Remove fuselage rotate upright position addition front rear turtledecks decks simple squarish structures scale building goes very quickly Right mount Ouadra engine recessed within nose Air ducting lots room heat escape important good engine performance use tapered stringers gussets eliminates side bulkheads January 1989 29 almost-completed lower wing Combina tion sweepback planform rounded tips makes elegant different model way Vida OR 97488 Another big help Hasegawa plastic SOC-3 Seagull 42scale used Foremost bomb releases work fine used large powerful servo Dive bombing lot fun scores slowly getting better very good Profile Publication volume Seagull now out print can still found some libraries Squadron/Signal Publications book Navy Air Colors Vol 1 Doll Jackson Riley has wealth information pho tos Seagull Its available hobby shops Decals used watersoluble type Major possible 1A-in balsa gussets used glue joints throughout model grain should always run parallel long side mass produce gussets rip 34-in strips off A-in balsa sheet Use tri angle mark off gussets strip Saw rough-shape final shap ing sander miter gauge set appropriate angle Glue gussets place slightly recessed will show up under covering add tremen NOTE LONOERON DOUBLERS NOTE WREN PLYWOOD IS CALLED FORAND TOP STRINGERS NOT OROWN USE S PLY NIGH QUALITY AIFCRAFTIN THIS VIEW FOR CLARITY GRADE DIRER PLY LITEI 3 PLY POPLAR II/RLITE PLY BOTTOMI ONLY NT -I NT I/N PLYWOOD NOTE SOME TRIMM LANSINGCRLONGERONNECEDOANY-LOCATE FILLTNGEARNMDOIJBLER RENSINE MOUNT BEI BALS NTO FUSELAGE BOG IWEIORT 7 21/N GUSSETS BOTTOM_OF L5ON ALL CORN INTERPLANE BUILT OP WITN yR ONEET ATCN CONT N OF BELI/B BALSAA SNEET STRINGERS A_________________________ OUSSET ALLBSNILL STRING JONTSFSR 3/IN SO SPRIEE DE IL2A AIRIJG I/NFILL1/4 3/4 SAND TO LONGERONFOR COOLING FAIRINS702ADOUBLERAIR DUCT BLOCKWINO FAININO BUILD OP HATCHWITN I/N1/4 BALSA SNEET BALSAVR 1/4 BALSA SPARS 1/4 BALSABEVEL SNEET 57 PAIRING BLOCKEA IEA2 SERVOAC ESSEA 56CR0 RATCALL ELCO RIBSSEC VE7 -IIZ3-ARE 3/DAS5A SHEET P ESACKNOPI E6-E17---S4 C WINO FAIRING IS ER_ VFORIRARD PIECE Et ID IN PLACE -53 E 4 /E3___________52 SIDE VIEW ES U FILL TRIS AREA WITR /B BALSA BETWEENE I_____ STRINGERSALL STABILIZER INNS ARE 3/32BALSA SHEET INTER ELEVATOR RIBS dous amount strength take few minutes make install Wing Upper lower wing construction similar begins spars have given up trying find straight wood sizes required now laminate spars Pin balsa center piece down along straight line over wax paper Glue outSPABIUZER side spruce pieces using Superjet cyanoacry late CyA hold pin until glue hardens Dont forget make slot dihedral brace Saw sand spar tips per plans Cut sand remaining parts R- 1 ribs stacked between %2in five-ply patterns carved sanded shape Make separate batch Left Outer wing panels built flat worktable Fourth twelfth ribs lower wing plywood accept bomb release hard ware interplane struts Right Both outer wing panels pinned table correct dihedral center section built up join Work carefully high-stress area ensure sound structure Sloppy construction could mean in-flight failure 30 Model Aviation Full-Size Plans Available Page 196 DERA DERB SERC DERS 1ThI iCOCKPiTjBAPY2Al 5/B SQ MAPLE CABANE HOLD DOWN 65 Cl 1 J5/RSD MAPLE CABANE MOLE DOWN DA ALL CROSS PIECESz ARE 3/16 SD OHMS CE TOP ONLY I/H BALSA SHEET AIR DOCT SIDES L SB BALSA PLANR INS 3/B BALSA SHEET 0 RIGHT THRUST FUSELAGETOPVIEWNOTE FUSELAGE STRINGERS3/16 DURAL ARE I/B BALSA SHEETLANOINS SEAR FIBERGLASS COWL UPPER WINS AILERON BALSA BLOCKSTABILIZER IS COVERED TOP H BOTTOM WITH BARSONS FIBERGLASS-COVER BEFORE ASSEMBLY TO FUSELAGE DORMS BALL-LINK I/BI/H BALGA FORWARD ANDI/H BALSA SHEET LEADING EDGE 3/30 BALSA SHEET FALSE LEADING EDGE STREAMLINED TUBING LAMINATIONS OF S/A BALSA SHEETI I/B PLY STAR STRUT ATTACKBALSA BRA SI/O BALSA URTI/B PLY NT SHEET-SANS I/B PLY HUH MOUNT TOP B EAI BOTTOM ARE H I/3D lTSOFT BALSA TRIMMED ELEVSAND TO SHAPE MODEL AVIATION ELEVATOR LECURTISS SOC-I SEAGULL OTABILIZER YE ribs right left panels top bottom wings Save patterns used ribs indicated plans Pin right spars plans Mark ribs location /B x Aqa strips form wing/aileron separation Notch ribs accordingly pin bot tom /8 x 4-in strips plans along other applicable parts Glue R-l ribs spar strips other parts being careful keep straight Fit shim up tip ribs carefully Add trailing false leading edges Add tip parts form base tip bow lamination Tip bows laminated five pieces /16 balsa well soaked water glued Towers Quick-Sand aliphatic resin Its necessary leave wing panel board lamina tions Add top YA-sq spar top /8 x A-in strips wing/aileron separa tion ailerons sawed apart wings later faced %2 balsa Pin completed right left wing pan els position board build center section join center sec tion spars built up bottom piece Add hardwood dihedral braces middle balsa spar segment finally top spruce spar segment Strong Pin %2-in bottom sheeting board aft front spar everything dry remove com Left look underside shows fillet blocks contoured lower wing landing gear Right Properly sized crew figures help maintain realism Theae figures carved 1/B-scale same airplane Loop antenna airplanes radio direction finder January 1989 31 plete wing Sand leading edge plank ing flush false leading edge glue leading edge caps took week build warp-free wing once parts sawed sanded wing finished sanded hold hands fly around house making Pratt Whitney sounds Brings good luck project Fuselage construction begins sides Follow outside line plans exactly both sides will identical basic fuselage box framework assem bled upside down over top view Make two sets crosspieces pin set down top view same firewall former 2C Add sides using pins triangles cut scrap plywood Glue second set crosspieces former FG-2 wing attachment piece shop permits lower wing can fitted fuselage box its still pinned board can diduse dining room table Use same care aligning wing would Pattern ship everything depends setting Drill holes FG-2 wing dow els Drill through wing wing tachment piece tap-sized drill tap piece 4-20 wing hold-down bolts Add remaining bottom formers stringers planking hatches Install top formers side formers stringers planking except can opy bows side stringers shaped top view plan sanded carefully attached using lots gussets nose planking tricky Notice above top longeron strip planking goes former 2 forward former 1 Aft 2 soft balsa fairing block used make smooth contour sheet plank ing runs 2 6 longerons doubled balsa aft nose planking wing fairing Shape longeron dou blers provide smooth transition tween side contours top bot tom B-IS BALSA SREE SAND TO SHAPE RH B-i THIS SECTION SHEETED WITH 3/32 BALSA TOP ABS BOTTOM -NOT SHOWN FOR CLARITY DIHEDRAL -BREAK I/3D PLY BRACE VH BALSA SHEET LEI S/32BAL FALSEGD 1/2 LYWOOD INSE FORWARD WINI HALO DOWI I/H F REAR OWOOD LB T WINS HOLE WN Iz- UPPE WI G P1 I/O TE BALSA FOCK H-I SPRUCE S REAR OP DETAIL Al PLY FACE PLATE II_I _ _ L-SLULiL7-~ AILERSSERGOLBLi AREAL-IL-I 3/ PLYBO B LOWEWI G P __REEASENUT SPROCE B BALI REAR SPAR B4B ORGSERGO LOCATION 3/32 PLRIBTYPICAL HINGE POCKET / 3/32 PLYWOOD INSET IN BOTTOM BALSA5SHEETING FOR WINS HOLO DOWN TE STOCK VS BALSA SHEET SAND TO SHAPE 1/2 xl BALSA LOWER WING DRAL DETAIL Although lower wing fairing timeconsuming carve shape its crucial realistic Seagull Start couple true square 3 x 3 x 18-in soft balsa blocks Use band saw make cutout receive lower wing precise fit block will have built up about 1814 using sheet balsa second cone-shaped rear piece fairing can made stock cut block receive wing Hasegawa plastic model useful visualizing conI/B BALD FILL IN SEAR ECESS SPROCE B BALSA FORWARD SPAR L-I Left Interplane Struts fasten wing studs 4-40 Allen-head bolts Mass balance upper aileron found necessary flutterfree performance Right top wing attached cabane struts using 2-32 Alien-head bolts screwed top wing studs 32 Model Aviation OH DOWELS INSTALL AFTER LOCATING HOLES AS PER INSTRUCTIONS H B- Full-Size Plans Available Page 196 NOTE THIS VIEW IS SHOWN UPOIGE GEIRNI/2 RALSA FRONT SPARFORWARD SPAR IS 1/4 3/R SPRUCE3/30 BALSA WING SHEETING UPPER WINS DIREDRAL DETAILCAPS SN 3/4 3/B BALSA CORE______ I/H BALSA REAR SPAR 6 LAMINATED WING TIP_______________ REAR SPAR IS I/4 SO BALSA CORE CAP WITH I/H SO SPRUCE PIECES TOP B BOTTOM R-7 R-3UPPER ES RU IONAL N-B125 ALUM -CABANE STRUTS N-S1/16 ILANEINGI/H BALSA R9 ONLYSHEET B BALSA RD SPAR TTAIL AT B-U NSOFL- 3/16SO BALSA 6 SHEET METAL SCREW 2 LNATIONS F I/U PLYR4 ONTTOM FOR INTERPLAN STRTIPS ARE D LAMINATIONS OF 16 BALSA SHEET 5/H SG HA ROW 0 50 N-2 1/B LSA SHEE FILL -HINGE POCKETS TYPICALNOTE ALL WINS RIBS ARE 3/32 BALSA1/B BALSA SHEET SHEET ESCEPT AS NOTEDSTRINGERS BALSA L LOWER WINS N-IFAIRINS- SEE TEST I/N PLY RELLCRANK MOUNT FALSE L KENS OF LU1/U ALUM CUTTHINSMS OF V PLT1-I AS H UIBESFO INTERPL E STRUTS L-I L-I L-I -- _________________ L-ILITYP SINGBALL LINE BARBS BS THREAD SLIL-2 -Y- L-2POCKETS 4-40ATNUSL-3L-4L-S BELLCRAN BUSHINGI/B PGELLORK MOUNT \J U/OSLY RIBL-3LANOING SEAR RANK MAD OF POSY PC OARS L-4 FUSELAGE FRONT I/N I/4BALSHEET LU TO HERE BALSA SHEET I/U PLYWOOD MOUNTING PLATE L-73/16RALSA SHEET FAIRING FRONTREMOVE SHADED AREA 1/35 PLY1/2 BALSA SHEETSPARCURTISS SOCI SEAGULL6 _BRACESANS TO SHAPE/ ____________________________________________________________[v32][b-1-10-1-10]]REAR SPAR DESIGNED BY PAUL BYNUM 6 _____________________________________ALL RIGHTS RESERVED tours landing gear mount should strongest part airplane Use epoxy glue mount place attach gear wood screws Build up landing gear itself fiberglass around area attaches fuselage matches fuselage contours hot air duct important dissipat ing heat Poor engine performance Giant Scale models often traced poor cowl ing design Remember its what comes its air goes out counts Seagull gets good performance hopped-up Quadra 35 stock Quadra 40 Zenoah 38 would also work well nor mally use 20 x 6 prop because scale size better performance obtained Zinger 18 x 6-10 Interplane cabane struts unique model interplane struts made 4 x Y -in spruce sanded airfoil shape cabane strut though cut single piece /5-in hard aluminum band saw After cutting out ca banes clamp vise true up Continued page 149 Paul says Cairn Terrier Mac hopes hell get some attention now Seagull framed up Just looking bones makes very satisfying project flying icing cake January 1989 33 short Frank has done something have long thought doing myself never quite got around has taken nine years writ ings cutting pasting has organized chapters contains arti cles similar nature Quite monumental task opinion forwarded Franks book Bob Underwood AMAs Technical Director asked Bob would consider Franks suggestion make book available AMA clubs some means other Just last week received copy letter Bob Frank states AMA consider ing making available clubs members might wish have Its just pride author ship makes believe would worthwhile undertaking readers similar opinion suggest drop line contact Bob Underwood directly enough let ters phone calls express interest proj ect might help convince AMA HQ staff go ahead publication Please let us know thoughts Have another safe month Seagull/Byrum Continued page 33 edges using file straightedge Studs made threaded steel rod screwed tapped plywood se curely glued inside wings Multiple lam inations /8-in five-ply work better single piece thicker plywood Use sharp tap avoid splintering wood Sat urate finished plywood thin CyA harden Incidence can adjusted screwing studs out studs themselves drilled tapped screws hold cabane interplane struts Always use Loctite keep screws vibrating loose satisfied way Seagull flies epoxy studs place Once thing permanently place Seagull can assembled field 15 minutes tail wheel takes lot abuse model make tail wheel assembly capable taking punishment used piece %2 music wire anchored nose gear mount Having tried varieties hinges like large Du-Bro type best Notice hinge pockets plans Hinges should also pegged toothpicks Giant Scale models still being lost through use unsuitable hinges careful stabilizer rm elevator rudder built same manner Cut leading edges LE trailing edges TE dimensions shown plans Mark centerline LE TE ball-point pen Pin LE TE over plans using shims tips keep cen terlines parallel building board Ribs cut patterns shown plan also marked center line gluing ribs LE TE centerlines should course meet Sheet top side fin %2 balsa Turn fin over reshim before sheet other side stab spars added after ribs glued LE/TE stab sheeted 6 balsa As fin stab turned over reshimmed other set spars added A6 sheeting glued rudder elevator ribs simple pieces 1/8 x 1-in balsa tapered meet TE Both rudder elevator built directly over plans After construction covered fabric per fullsize Seagull recommend using servo per elevator handle loads case no need join two elevator halves avoid adverse yaw ailerons need about 20/80 differential down-to-up throw right aileron goes up 200 left aileron should go down So didnt build enough differential model initially able obtain electronically adjusting settings Futaba 8FGA radio plans show arrangement should give increased mechanical differen tial over original scheme used course two servos used ailerons top bottom ailerons linked together tie rod done full-scale plane found necessary clude external static balances aile rons prototype large canopy usual focal point model case January 1989 149 Seagull/Byrum Continued page 149 presents no special problems parts should carefully sanded primed before assembly stringers canopy used basswood available railroad section hobby shop After covering priming fuselage finishing cockpit interior canopy glazed 015 clear plastic Sig Wil holds RC-56 very good adhesive taching canopy stabilizer fin covered Parsons brand fiberglass before being joined fuselage Glass cloth also used wing fairing interplane struts wheel pants wooden surface covered fabric Dan Parsons has very good set instructions will send cloth method much easier infinitely lighter old poly ester method Open framework should covered Super Coverite primed nitrate dope sprayed avoid brush stroke marks used Sig Superoote clear nitrate dope followed col ored butyrate dope Apply several coats rub down steel wool magnet will remove small steel particles re main Supercote silver particularly tractive color heavily pigmented Before flying model check radio power off engine running full throffle good practice also make power check using smaller prop youll flying ap proximates in-flight higher rpm 25 lb Seagull takes off about 100 ft no wind Rudder response dur ing takeoff very good launches smooth graceful landing technique try hold foot off runway ap plying more up elevator air plane slows down until finally settles itself dont always succeed I get nice landing interest encouragement Bill Winter acknowledged appreciated Also advice library staff National Aviation Space Museum Washington DC very helpful lads very very knowledgeable helped make day spent doing re search Seagull best life written Seagull 25 flights flight emo tional experience Hope enjoy yours well Radio Technique/Myers Continued page 35 AMA Academy Model Aeronautics National organization aeromodelers member NAA representative United States America negotiations world pub lisher Model Aviation magazine EAA Experimental Aircraft Association National organization builders homemade man-carrying aircraft Frequent users RC mod els investigate verify performance air craft designs EC Executive CouncilGovermng body AMA consisting President Executive Vice-President Executive Director 11 Dis trict Vice-Presidents FAA Federal Aviation Administrationpart US Federal Government charged regulating transportation use air above nation FAI Federation Aeronautique Internationale Organization oversees coordinates aerospace competitions records based Paris France FC Frequency CommitteeAdvisory body AMA Executive Council matters pertain ing obtaining using radio frequencies hobby purposes FCC Federal Communications Commission part US Federal Government charged regulating radio frequency transmissions FM frequency modulationa system im pressing information radio frequency trans mission adding information moves assigned radio frequency intelligible man ner FSK frequency-shift keyinga system im pressing information radio frequency trans mission shifting between two radio frequen cies intelligible manner system actually used RC systems described FM systems HQ headquartersin case AMA lo cated 1810 Samuel Morse Drive Reston VA 22090 NAA National Aeronautic Association members include EAA AMA other US aviation associations US national aero club recognized FAI PC printed circuita method connecting electronic components etched copper foil path ways PCM pulse-code modulationa system encoding modulation radio frequency use computer words can decoded control commands computer receiver PWM pulse-width modulationa system encoding modulation radio frequency uses time between pulses analog desired control position system common system years 1969-1988 RC sometimes RIC radio-controlled Describes systems human commands delivered machines way radio link RF radio frequencypertains systems generate electromagnetic radiations ra dio frequencies RFI fradio frequency interferenceany elec tromagnetic radiation degrades radio link RC system RXradio receiver XM7Rradio transmitter XTAL sometimes XTL crystalcommon frequency-determining element XMTR RX Battery/Smith Continued page 36 Making use dual battery system relatively simple does entail adding negative positive lead receiver connector supply current Generally existing power connector built receiver can used servo power supply receivers experience Great Performance Quartet x DALOTEL 850 SPAN 69 InsWING AREA 830 sq ins U SPAN 76 EXTRA 230 WING AREA 900 sq ins series Sport Scale Balsa ARF Airplanes 120-4 cycle equivalent motors available direct select hobby shops - ZEMPRO MARKETING I- PO BOX 3076 OAK RIDGE TN 37830 PHONE 6154826188 January 1989 153 CHIPMUNK 850 SPAN 70 insWING AREA 850 sq ins ZLIN 526 SPAN 72 insWING AREA 900 sq ins