Sig Mfg. Co., Inc....401-7 South Front Street....Montezuma, Iowa 50171

The Spacewalker II Story

In 1986, inspired by the classic PT-19 and Ryan millitary trainers of WWII, North Carolina EAA member Jesse Anglin designed and built an open-cockpit, low-wing, single-place airplane for his own personal sport flying. To make it more economical to fly, he sized it around a Continental 65 h.p. engine. Jesse always said that his new airplane gave him the feeling of being in open space, almost as if he was flying without an airplane, and that's why he named it Spacewalker. In the years since then, the single-place Spacewalker has attracted a lot of attention from both homebuilders and R/C modelers alike.

Two of the first full-scale Spacewalkers to take to the air after Jesse's own, were built by Sig Mfg. executives Hazel Sig and Maxey Hester. As Hazel and Maxey flew around the country in their single-place Spacewalkers, they got the same question everywhere they went, "What about a two-place version?"

With that in mind, Jesse went back to the drawing board and designed the Spacewalker II. The new two-place airplane featured the same general constuction as the original, with a welded steel tube fuselage and a wood wing. To accommodate the extra passenger, Jesse added 13 inches to the overall fuselage length, and extended the wingspan 24 inches longer than the single-place.


Maxey and Hazel built the first prototype Spacewalker II in the Sig factory, using a 65 h.p. Continental for power. In order to get it ready for the rapidly approaching 1990 Sun-N-Fun Fly-In in Lakeland, Florida, they sparyed on a quick and simple red and white paint scheme. Then with only a few hours on the aircraft, Jesse came to Montezuma to fly it down to Florida, flying in formation with Hazel and Maxey in their two single-piece Spacewalkers. You can read all about their trip to Sun-N-Fun in the September 1990 issue of "Kitplanes" magazine, and in the July 1990 issue of "Sport Aviation" magazine.

In the winter of 1991, Maxey brought the Spacewalker II back into the Sig factory to install a 100 h.p. Continental 0-200 engine for better performance. At the same time, the simple red/white color scheme was removed and the more familiar yellow and red Spacewalker-style color scheme was put on.

Unable to keep up with the demand for plans for his two popular designs, Jesse Anglin sold all of his rights and interest in the Spacewalker and Spacewalker II in September of 1991 to Rick Warner of Tampa, Florida. For futher information on either of these full-scale homebuilt aircraft contact:
7801 N. Armenia Ave.
Tampa, Florida 33604.

Die-Cut Balsa Sheets
23/32"x4"x18" W-1 Wing Ribs Sheet #5 43/32"x4"x18" W-2 Wing Ribs Sheet #4 73/32"x4"x18" W-3 Wing Ribs Sheet #3 13/32"x3"x12" Apron pieces F-5 Sheet #2
13/32"x3"x18" F-1, F-2, F-3 Formers Sheet #6 13/32"x3"x18" F-4, F-5, F-6A Formers Sheet #7 11/8"x3"x12" FS-1 Sheet #1
Sheet Balsa
43/32"x1-1/2"x21" Top Wing & Aileron Sheeting, Wing Aileron cutout Sheeting 43/32"x2-1/2"x42" Wing Leading Edge Sheeting & Servo Bay Sheeting 43/32"x3"x30" Wing Center Sheeting & Top Deck Side Sheeting 13/32"x4"x12" Center Top Deck Sheeting
243/32"x3-5/16"x1-3/4" Spar Webs 21/8"x1-1/2"x21" Aileron Leading Edge 13/16"x6"x4" Landing Gear Fill-In 23/8"x3"x4-3/4" Nose Block
Stick Balsa
13/32"x1/8"x18" Top Main Spar Spacers 163/32"x1/4"x30" Cap Strips 43/32"x1/2"x21" Bottom Wing & Aileron Sheeting 43/32"x1"x42" Wing Trailing Edge Sheeting
41/8"x3/16"x21" Aileron Spars 71/8"x3/16"x36" Balsa Fill Straps 71/8"x1/4"x36" Top Stringers, Side Stringers 41/8"x5/16"x36" Diagonal Ribs (Stab, Elevator, Fin, Rudder) ,Bottom Stringer, Fabric Attach Strips, Cable Exit Guides
21/8"x3/4"x42" Leading Edge 123/16"x3/16"x30" Main Frame, Braces for Fin & Servo Mount Plate 43/16"x3/16"x42" Forward Spars Top & Bottom 43/16"x3/8"x42" Rear Spars Top & Bottom
23/16"x3/4"x42" Leading Edge Cap 21/4"x1/4"x24" Front Top Stringers 35/16"x5/16"x30" Tail Surface Ribs 55/16"x1/2"x30" Tail Surface Leading & Trailing Edges
25/16"x1"x2-5/8" Trailing Edge Support 11/2" Triangle x 6" Braces for Rear L.G. Blocks 13/4" Triangle x 24" Braces for Firewall and PW
Silkscreened Balsa
13/16"x3"x42" WS-1. WS-2, WS-3 & WS-4 Sheet #9 15/16"x3"x24" All Rudder, Stab, Elevator, and Fin Parts Sheet #8
Block Balsa
13/8"x1-1/8"x6-1/2" Trailing Edge Fill-In Block 21/2"x2-3/4"x7/8" Landing Gear Support Blocks
15/16"x3/4"x1-1/8" Basswood Control Horn Mount 23/4"x3/4"x1-1/2" Basswood Wing Hold Down Block 13/8"x3/8"x12" Basswood Servo Rails 23/8"x7/16"x3" Basswood Rear L.G. Blocks Grooved
23/8"x3/4"x3" Basswood Front L.G. Blocks Grooved 23/16" dia. x 2-1/2" Birch Dowels Pushrod Ends 21/4" dia. x 1-1/4" Birch Dowels Wing Hold Down Dowels
11/8"x1/2"x14" Hatch Cover Support 53/16"x3/16"x36" Fuselage Main Frame 11/4"x1/2"x6" Tiller Bar Mount 61/4"x1/2"x40" Main Spars, Spar Doublers
15/16"x5/16"x5" Elevator Joiner
Die-Cut Poplar Plywood (Lite Ply)
21/8"x6-7/8"x26" PS-1, PS-2 11/8"x6-7/8"x24" PT-1 11/8"x8"x13-3/4" F-6, F-7, F-8, F-9, F-10, Servo Mount Plate, G-1, TWM, PB-1, Wing Saddle Carving Guage, Dihedral Guage 21/8"x8"x13-3/4" W-1A, PF, W-3A, WTP, SW-1, SW-2, SW-3, SW-4


Die-Cut Birch Plywood
11/16"x8"x8" Wheel Pant Mount Plate, Front & Rear Instrument Panels 13/32"x6"x9" Hatch Covers, L.G. Mounts, PW, Wing Hold-Down Plates 25/32"x8"x8" F-1 15/32"x3"x13-1/2" DB-1, DB-2
Sawn Plywood
21/64"x7/8"x36" Birch Plywood Wing Straps
Wire Parts
13/32" dia. x 8" Straight Wire for Servo End of Elevator Pushrod 11/8" dia. x 6-3/4" Formed Top Shock Strut Wire 11/8" dia. x 15-11/16" Formed Bottom Shock Strut Wire 13/16" dia. x 22" Formed Front Main L.G. Wire
13/16" dia. x 19-5/8" Formed Rear Main L.G. Wire
Plastic Parts
1Left Dummy Engine Cylinders 1Right Dummy Engine Cylinders 1Cylinder Shrouds, Fuel Cap Cover, Shock Springs, Compass 2Wheel Pant Halves (Left-Hand)
2Wheel Pant Halves (Right-Hand) 1Left Wingtip 1Right Wingtip 1Cowling Half (Left-Hand)
1Cowling Half (Right-Hand) 1.030x5/16"x17" ABS Cowl Joiner Strip
Miscellaneous Parts
2.030x5"x12" Clear Plastic Windshields 11/2" dia. x3" White Foam Cockpit Coaming, Grooved 13/32" wide x7" Cockpit Lacing 132" Long Fiberglass Pushrod Shaft (for elevator)
19-1/4"x12" 6oz Fiberglass Cloth (for Landing Gear) 12"x30" Fiberglass Tape (for Wing Joint) 1.130 o.d. x20" Nylon Tubing (for Rudder Cable Guides, Throttle Pushrod) 11/16"x20" Steel Cable (for Throttle Pushrod)
1Full-Size Plans Plate 1 1Full-Size Plans Plate 2 1Full-Size Plans Plate 3 1Instruction Book
1Decal Sheet 23/1/2"x21" White Offset Paper for Servo Leads 38-1/2"x11" 3-View Drawings
Hardware Pack
12#2x3/8" Sheet Metal Screws (for Tail Brace Wires, Servo Hatch Covers) 2#2x3/4" Sheet Metal Screws (for Elevator Horn) 4#4x3/8" Sheet Metal Screws (for Wheel Pant Mounts) 8#4x1/2" Sheet Metal Screws (for L.G. Straps)
62-56 x 1/2" Mounting Bolts (for Tail Brace Wires, Rudder Horn) 44-40 x 3/16" Mounting Bolts (for Aileron Servo Mounts) 16-32 x 1" Mounting Bolt (for Tiller Bar) 64-40 x 1/2" Self-Tapping Bolts (for Cowling)
26-32 x 3/8" Socket Head Bolts (for Wheel Pant Mounts) 410-32 X 1" Socket Head Bolts (for Engine Mount) 62-56 Hex Nuts (for Tail Brace Wires, Rudder Horn) 44-40 Blind Nuts (for Aileron Servo Mounts)
410-32 Blind Nuts (for Engine Mount) 64-40 Brass Threaded Inserts (for Cowling) 16-32 Aircraft Lock Nut (for Tiller Bar) 4#3 Flat Metal Washers (for Aileron Mount)
2#6 Flat Metal Washers (for Tiller Bar) 6#8 Flat Metal Washers (for Wheel Spacers) 21/4"x20"x1" Nylon Wing Bolts 15Hinges
15#28 Steel Pins (for Hinges) 32-56 Threaded Couplers (2 Rudder, 1 Throttle) 32-56 Nylon R/C Links (2 Rudder, 1 Throttle) 12-56 Solder Link (for Throttle)
44-40 x 8" Threaded Rod (1 Elevator, 1 Rudder, 2 Ailerons) 44-40 Metal R/C Links (1 Elevator, 1 Rudder, 2 Ailerons) 44-40 Solder Links (1 Elevator, 1 Rudder, 2 Ailerons) 1Large Righthand Nylon Control Horn (for elevator)
2Molded Nyon 90 deg. Bellcranks (for Aileron Control Horns) 4Large Molded Nylon Landing Gear Retaining Straps 23/16" I.D. Molded Nylon Wheel Pant Mounts with Brass Inserts 1Molded Nylon Heavy-Duty Rudder Control Horn
1Molded Nylon Heavy-Duty Tiller Bar 1.027 x 200" roll Steel Cable (for Rudder Control and Tail Brace Wires) 121" roll Soft Copper Wire (for wrapping Landing GearWire) 23/16" Wheel Collars (for Main Landing Gear)
26-32 x 1/8" Headless Set Screws (for Wheel Collars) 14Steel Brace Wire Attach Tabs 103/32" o.d. x 1.2" Aluminum Tubing (for Tail Brace Wires)
Tail Wheel Assembly
1#1 Formed Steel Leaf Spring 1#2 Formed Steel Leaf Spring 13/32" dia. x 3-1/8" Formed Tailwheel Wire 1Molded Nylon Tailwheel Bearing 3/32" hole
1Molded Nylon Tailwheel Steering Arm 26-32 x 1/2" Mounting Bolts 26-32 Square Anchor Nuts 24-40 x 3/8" Mounting Bolts
24-40 Aircraft Lock Nuts 14-40 x 3/16" Set Screw 23/32" Wheel Collar 2C.B. #5511 Steering Springs
2#2 Flat Washers 14-40 Headless Set Screw



There are many different glues available today for model construction that it can be confusing to even the experienced modeler. To simplify matters, most glues can be classified as one of four basic types:
  1. Fast cyanoacrylate adhesives (abbreviated as C/A) such as Sig CA, Hot Stuff, Jet etc.
  2. Easy to use water-based wood glues such as Sig-Bond (yellow) and Sig Super-Weld (white).
  3. Super strong (but heavier) two-part epoxy glues such as Sig Kwik-Set (5 minute cure) and Sig Epoxy (3 hour cure).
  4. Traditional solvent-base model cements such as Sig-Ment.
Each of these types has different characteristics and advantages. Often times, the choice of which type to use is strictly a matter of personal preference based on your experience with a previous model. To help speed up assembly, C/A glue is recommended for general construction. You should also have on hand some epoxy (both 5 min. and slow dry) and Sig-Bond because these glues are called out in several places in these instructions.

Sig CA, like mose brands of cyanoacrylates, come in three viscosities- thin, medium, and thick. An accellerator spray and debonder are also available and are described below.
  • Sig CA Thin - Watery consistency, thin CA should only be used when the two parts to be joined are in perfect contact with zero gap. Capilliary action pulls this glue deep into the wood resulting in a very strong bond and it dries in just a few seconds. Thin CA can be used to tack assemblies together, but these joints should be glued again later with medium or thick CA.
  • Sig CA Medium - Our medium thickness CA is excellent for almost any step during construction. The extra thickness allows the glue to fill small gaps, but it does dry a little slower than a thin CA. If you want only one type of C/A, use medium thickness.
  • Sig CA Slow - This thickest formula is good for filling large gaps and building up strong fillets at joints requiring extra strength. It also dries slow enough to allow you to apply it to one part and position it on another before it dries. (With the thin and medium C/A's, the parts must be in contact and positioned correctly before glue application.) This feature is useful when laminating large sheeted areas like a fuselage side and a fuselage doubler.
  • Sig Kwik-Shot Accellerator - Spraying accellerator on CA (any thickness) will cure it almost instantly. Although CA is fast, it's sometimes nice to speed it up even more.
  • Debonder - This can be used to separate parts, but you'll probably use it for unsticking your fingers more than anything else!

CAUTION: Some people have experienced allergic reactions when exposed to epoxy or cyanoacrylate glues. This is very rare. However, it is extremely important that such glues, and also paints, thinners and solvents, be used with adequate ventilation to carry fumes away.


Any references to right or left refers to your right or left as if you were seated in the cockpit.

To build good flying models , you need a good straight building board. Crocked models don't fly well! The building board can be a table, a workbench, a reject "door core" from the lumber yard, or whatever- as long as it is perfectly flat and untwisted. A 2ft.x6ft. board is recommended for the Spacewalker II.

Cover the top surface of the building board with a piece of celotex-type wall board or foam board, into which pins can be easily pushed. Don't hesitate to use plenty of pins during assembly to hold drying parts in their correct position.


When pinning or gluing parts directly over the full-size plans, cover the plan with wax paper or plastic kitchen wrap to prevent gluing the parts to the plans.

The balsa die-cut parts have identification numbers printed on them. The plywood die-cut parts do not. Use the "Key to Plywood Parts" to mark the identification numbers on the corresponding plywood parts.

Leave all the die-cut parts in the sheets until needed for construction. Remove pieces from the sheets carefully. If difficulty is encounted, do not force the part from the sheet. Use a modeling knife to cut it free.

All of the other kit parts can be identified by the "Complete Kit Parts List".

Sort the different sizes of sticks and sheets into individual piles to avoid confusion during building. Cut all long pieces of balsa first, followed by medium lengths, before cutting up any full length strips into short pieces.


An assortment of different size sanding blocks are indispensable tools for model construction. A good general purpose block can be made by wrapping a 9"x11" sheet of sandpaper around a piece of hardwood or plywood. Use three screws along one edge to hold the overlapped ends of the sandpaper. Put 80-grit paper on the block during general construction. Switch to 220-grit paper for final finish sanding just before covering.

Another handy block can be made by gluing sandpaper onto a 24" or 36" long piece of aluminum channel stock. Most hardware stores carry a rack of aluminum in various sizes and shapes. This long block is very useful for sanding leading and trailing edges accurately.


The quickest and most efficient way to complete a model is to work on several pieces at the same time. While the glue is drying on one section, you can start on or proceed with another part. Work can even go forward on several sections of the same assembly at the same time, such as the front and rear sections of the fuselage.


Keep in mind that the numbering sequence used in these instructions was chosen as the best way to explain the building of each major component and is not intended to be followed exact one-two-three fashion. Start on the wing at No.1 and after doing as many steps as is convenient, flip over to "Fuselage Construction" and do a step or two or three, then over to "Tail Assembly" and so forth. You will, of course, arrive at points where you can go no farther until another component is available. For example, you need a nearly completed wing before the fuselage can be entirely completed. Plan ahead! Read the instructions completely and study the full size plans before beginning construction.


You will need at least a four-channel radio system for your Spacewalker II to operate the ailerons, elevator, rudder and throttle. Heavy-duty servos with at least 60oz./in. of torque are required for all of the flight controls. Also, use a receiver battery with at least a 1000 mAH capacity to power those servos for a safe amount of time. Be certain that your radio system's frequency is approved for use in R/C model aircraft. Using a frequency assigned to R/C model cars not only endangers your model to interference from model car drivers (who may not be in sight), it also is against the law.


To answer the question we are sometimes asked - no, we do not print parts on wood to save money. It is actually more expensive to print the parts using a silk screen press than it is to run an equivalent sheet through our automatic feed die cutting machine. If we hand-sawed the parts it would be even more expensive and the labor cost would have to be added to the kit price. We believe that most modelers would rather cut their own out and save the cost. Since there are not many thick parts in our average kit, it really doesn't consume a lot of the total building time for the builder to do the parts.


Wing Subassemblies

Before beginning construction on the wing, there are a number of subassemblies that should be built and set aside until needed. This is done to avoid interruptions during the flow of the wing construction.


  1. Cut four 1/4"x1/2"x19-1/4" spruce spar doublers from two of the 1/4"x1/2"x40" spruce sticks provided with the kit.
  2. The main spar assemblies are built by laminating a 1/4"x1/2"x40" spruce main spar with a spar doubler (from part a of this step). Build four main spar assemblies using a thin film of slow-drying epoxy to join each laminate. It is very important that the main spar assemblies be kept perfectly straight while drying. Any bends or twists built in now are there to stay.


Join two die-cut 1/8" lite-ply W-1A sub-ribs to two W-1 ribs, being certain to make one left and one right. These subassemblies will serve as the two center ribs in the wing center section. The remaining two W-1A sub-ribs are not installed until the wing has been fitted to the fuselage.


Use scrap pieces of 1/16" balsa to join four W-3A sub-ribs to four W-3 wing ribs, being certain to make two left-hand and two right-hand. These subassemblies are used at the inboard and outboard ends of each aileron.

Wing Construction

The wing is built in two halves, which are joined later to complete the wing. Pin down the plan on your building board and cover it with wax paper.


  1. Pin down one of the laminated spruce main spar assemblies over the plans, being careful to position the outboard end of the spar doubler correctly.
  2. Glue and pin all of the 3/32" balsa wing ribs into position except for the W-1/W-1A subassembly at the wing center. Be sure to use the wing rib subassemblies that you prepared earlier in step 3.

5. Glue another laminated spruce main spar assembly to tops of the ribs. Use a builder's triangle to make certain each rib is vertical.


Locate the die-cut 1/8" lie-ply dihedral guage. Position the W-1/W-1A wing rib assembly in its position on the plans using the dia-cut lite-ply dihedral guage to insure that it is at the proper angle. Glue the rib assembly to the spars.


Glue a 3/16" sq. x 42" balsa forward spar in place on top of the ribs.


Glue the 1/8"x 3/4"x42" balsa leading edge in place at the front of the ribs.


Glue in two 3/16"x3/8"x42" balsa rear spars. You will have to slide the bottom spar under the ribs and lift it in position.


Attach a 3/32"x1"x42" balsa trailing edge sheet in place on top of the wing ribs. Careful! Make sure that the back edge of the sheet is in the right place, directly above the trailing edge on the drawing.


Trim and glue all of the spar webs on the front side of the main spars. SW-1, SW-2, SW-3, and SW-4 are all die-cut lite-ply; the remaining spar webs are 3/32"x3-5/16"x1-3/4" pre-cut balsa. (No spar webs should be installed on the backside of the spars now because you will need to get at the pins in the bottom spar when it is time to remove the wing from the building board.)


  1. Sand the top of the leading edge to the contour of the ribs. Be careful to avoid sanding the ribs and changing their shape.
  2. The leading edge is sheeted with 3/32"x2-1/2"x42" balsa. The sheeting should overlap onto the forward spar only halfway. Start gluing at the spar and work forward to the leading edge, pinning or taping the sheet in place as you go. There will be excess sheeting forward of the leading edge to carve and sand later.
13. Fill the gap on the tops of the W-2 and W-3 wing ribs above the spar with spacers made from short lengths of 3/32"x1/8"x18" balsa. The spacers on top of the W-1 ribs will be added later. When dry, sand the spacers even with the tops of the ribs.


Cut two 1/8"x3/16"x21" balsa aileron spars to the correct length and glue them to the wing, one on top and one on the bottom.


Use a 3/32"x1-1/2" balsa sheet for the top aileron sheeting. Glue this sheet to the top of the wing as shown. This sheet will eventually be sliced down its length when the aileron is cut from the wing.


Glue the 3/32"x1/4" balsa capstrips to the tops of the wing ribs and aileron ribs as indicated on the plan.


17. A paper tube to pass the servo leads is made from the 3-1/2"x21" sheet of paper provided. Roll the paper, insert it through the rib holes, and glue it to the ribs. When dry, remove the wing from the building board.

Now is a good time to look over your basic wing structure for any joints that may need another coat of glue. In particular, inspect the bond at all the rib/spar/web joints.


Glue in the remaining seven balsa spar webs to the back of the main spar.


  1. Carefully cut away all of the rib alignment tabs, then sand the bottom of the ribs and the rear edge of the trailing edge sheeting to the airfoil shape.
  2. Glue the 3/32"x1"x42" balsa trailing edge sheeting to the bottom of the wing. Use epoxy glue where the bottom sheeting joins the top sheeting. The epoxy will not warp the trailing edge (as water- based glues might) and will strengthen the sharp edge so that it is not easily damaged.


  1. Notch the bottom trailing edge sheeting in the position shown on the plan for the die-cut 3/32" plywood wing hold-down plate.
  2. Cut the 3/8"x1-1/8" special-cut balsa trailing edge fill-in block to fit between the W-1 ribs and glue it in place.
  3. Glue the wing hold-down plate to the fill-in block at the notch that you made in "part a" of this step.


  1. Add the 3/16" sq. balsa forward bottom spar.
  2. Sand the leading edge to the bottom contour of the wing as you did in step 12.
  3. Cut a 3/32"x2-1/2"x42" balsa sheet to a length of 36". Save the scrap for step 23c.
  4. Glue the 3/32"x2"x38" balsa bottom leading edge sheeting in place in the same manner as the top leading edge sheeting. Notice that the sheeting will end up about an inch short of the wing center. Later the sheeting will be cut away even futher.


  1. When dry, trim the excess top and bottom sheeting flush with the front of the leading edge.
  2. Glue the 3/16"x3/4"x42" balsa leading edge cap to the front of the wing. Use tape or pins to hold the leading edge cap flat. Let dry.
  3. Carve and sand the leading edge cap to the shape shown on the plans. Take your time with this step and try to keep the shape uniform along the entire leading edge. Cut out the Leading Edge Carving Guide and glue it to scrap balsa or light cardboard to check the shape at random spots along the leading edge.


  1. Add the 3/32"x1/2"x21" balsa bottom wing sheeting.
  2. Add the 3/32"x1/2"x21" balsa bottom aileron sheeting.
  3. Use the piece of 3/32"x2" balsa sheet from step 21c for the servo bay sheeting. Make the pushrod exit cutout as shown on the plan, then glue this sheeting to the bottom wing surface only.
  4. Glue in all the 3/32"x1/4" balsa capstrips on the wing bottom.

Check to make sure that your servo will work with the pushrod exit cutout that is shown on the plans. We used Airtronics #94732 servos and these cutouts worked well. Depending on the size of your servos, you may need to move the cutout right or left of center. Remember to reposition the W-3A rib to line up the control horn with the pushrod exit cutout.


  1. Cut two 1/8"x1/2"x3-1/4" spruce hatch cover supports from the 14" spruce stick provided.
  2. Glue in the rear support so that it fits under the edges of the capstrips and overlaps the forward edge of the servo bay sheeting by 1/4". The forward support is glued to the back of the balsa spar web with its ends under the edges of the capstrips.
  3. Trim a die-cut 3/32" plywood hatch cover to fit between the capstrips. While holding the hatch cover in place, glue a 3/32"x1/4" balsa strip to the front edge of the forward spruce support to give the covering material a place to attach. Don't glue the hatch cover!
  4. Drill 1/16" dia. holes through the corners of the hatch cover into the hatch supports. Remove the hatch cover, then redrill the holes in the hatch cover with a 3/32" drill bit. The hatch cover is held on with four #2 x 3/8" sheet metal screws. Be sure to mark each cover so you can tell later which hatch goes with which wing!


Saw out the aileron using a razor saw to cut through the ribs. Exactly where you cut is not critical as long as it's somewhere between the rear spars and the aileron spars. Cut through W-3 rib on the outboard end of the aileron, then remove and discard the part remaining attached to the aileron. Use a sharp modeling knife to cut the top aileron sheeting and temporary spacers on the inboard end.


  1. Trim and sand the back of the wing cutout until the ribs are even with the rear spars. Use a long sanding block to sand just enough to make the back edge flat, as shown.
  2. Sheet the back of the wing cutout with 3/32"x1-1/2"x21" balsa, cut to length. When dry, trim the sheeting to airfoil contour.


  1. Sand the outboard end of the wing bringing all spars, leading edge and trailing edge flush with the end rib.
  2. Glue the die-cut lite-ply WTR wingtip rib to the end of the wing.
  3. The ABS wingtip can be glued to the wing using CA. Be sure to clean and lightly sand the inside of the ABS where the glue will come in contact. Notice that the wingtip overlaps only onto WTR when glued in place. Also notice that WTR does not extend all the way back to the rear point of the wingtip. The small gap that remains can be left as is or filled with scrap balsa or model filler.
  4. Feather the wingtip into the wing using model filler.


  1. Trim and sand the front of the aileron in line with the angled, die-cut slits in the ribs.
  2. Add the 1/8"x1-1/2"x21" balsa aileron leading edge.
  3. When dry, sand the aileron leading edge to shape.
  4. Sand each end of the aileron flat.


  1. Glue in the W-3A aileron rib in the position shown on the plans. The aileron rib may need some trimming to slip into place.
  2. The aileron control horn is actually a 90 deg. bellcrank. Cut a slot in the aileron leading edge, just large enough for one arm of the horn, then epoxy the horn firmly in place on the W-3A rib. See the "Wing Rib Cross Section" on the plan to see exactly how the horn is positioned.


Cut hinge slots in the aileron leading edge and the wing cutout to accomodate the nylon hinges. Use four hinges per aileron, in the positions shown on the plans. Trial fit the hinges and aileron on the wing, without glue, to check for smooth operation and proper fit. If there is any mismatch or binding, alter the slots as necessary to correct. Notice that the aileron should be positioned on the wing so that it has equal gap, about 1/8" at each end. The gap at the leading edge should be 1/16" or smaller. The hinges should not be glued in place until after the wing and aileron have been covered.


By placing the control horn aft of the hinge line, the aileron will automatically have different movement, that is, it will hinge slightly further up than down. The further aft of the horn, the more "differential". On an airplane like the Spacewalker II, differential ailerons improve the quality of the turns in flight. We recommend that you use the hoen position shown here.


Repeat steps 4 through 30 for the other wing half.

Joining The Wing Halves


  1. Sand the inboard ends of the wing halves bringing the spar leading edges, and the trailing edges flush with the end ribs. Trial fit the two halves together with the die-cut 5/32" plywood BD-1 and DB-2 dihedral braces. The center ribs should meet flush when the dihedral braces are clamped in place temporarily. The long dihedral braces will automatically set the proper dihedral.
  2. Use slow-drying epoxy glue to join the halves. DB-1 and DB-2 together. Hold everything in place with clamps until dry. Try for good joints and don't be stingy with the glue during this step! Before it dries, double check that the two halves are aligned perfectly with each other.


  1. Add the 3/32"x1/8" balsa spacers to the top spar notches on the four W-1 wing ribs. When dry, sand the spacers even with the tops of the ribs.
  2. Install the top center sheeting using pieces cut from the 3/32"x3" balsa sheet provided. Don't sheet the bottom yet.
  3. Make small cutouts in the top center sheeting to pass the wires through.


Refer now to the Fuselage Instructions, step 67, before proceeding.
Several steps in the fuselage instructions actually involve work on the wing. Fuselage construction must be completed through step 73 before continuing in this section.


  1. Trim the two center W-1 ribs for the rear landing gear blocks, using the W-1A ribs as guides.
  2. Fit the basswood rear landing gear blocks to the wing by beveling the ends to match at the center where they meet. Glue the blocks in place.
  3. Reinforce each rear l.g. block with short lengths of 1/2" balsa triangle stock glued to the top of the blocks and SW-1.
  4. Add the die-cut 3/32"x1/2"x3-3/8" plywood l.g. mount plate to the wing. These plates provide a solid base for the nylon l.g. straps, and should be flush with the surface of the rear l.g. blocks. See the "WING RIB CROSS SECTION at W-1" for more clarity on their position.


  1. Carefully trim the wing leading edge flush with the support blocks to make a seat for the front landing gear block.
  2. Cut away the exposed portion of the two center W-1 ribs so that they are even with the front notches in the W-1A sub-ribs.
  3. Trim the front landing gear blocks so that their inner ends meet at the center with the proper dihedral angle and the outer ends are flush with the W-1A sub-ribs. The l.g. blocks must sit firmly in the W-1A front notches and should also sit flat against the support blocks and leading edge. Epoxy the blocks in place, being sure to use plenty of glue.


  1. Cut out the bottom center sheeting that fits between the front l.g. blocks and the rear l.g. blocks out of 3/32"x3" balsa provided. Glue it in place.
  2. Add the 3/32" balsa center sheeting to the bottom of the wing from the main spar back to the trailing edge.
  3. Glue scraps of 3/32" balsa to the sides of W-1A sub-ribs to finish off the bottom center sheeting.


Cut two 14" strips from the two inch wide fiberglass tape material provided. Apply the strips to the top and bottom of the wing center joint using slow drying epoxy. You should cut the bottom strip into two pieces to avoid the slots for the landing gear wires.
To apply the strips:
  • Coat the wing center with slow-drying epoxy.
  • Lay the fiberglass strip on the top of the glue.
  • Holding one end of the strip so it won't move, "squeegee" the glue through the tape with a small paddle to smooth the tape and remove the excess glue.
  • When dry, sand lightly to remove any rough spots, being careful not to sand into the fiberglass tape itself.