"Topper" Article and Plans: Best 4-Way AYSC Plane
March 1962 American Modeler

March 1962 American Modeler Table of Contents Aeromodeling has seen significant changes over the decades both in technology and preferences. Magazines like American Aircraft Modeler, American Modeler, and Air Trails were the best venues for capturing snapshots of the status quo of the day. All copyrights are hereby acknowledged.

The "Topper" is a general purpose control line stunter with a profile fuselage, a built-up wing, and power provided by a Fox .25 engine. Designed by John D'Ottavio, it originally went by the name of "Falcon," as evidenced by the lettering on the model flown by Eddie Elasic in the 1961 Air Youth State Competition (AYSC) held at Willow Grove NAS. He and John combined talents to come up with the design. It was awarded the honor of "Best 4-Way AYSC Plane." What are the 4 ways? I see endurance, speed, and stunt, but I'm not sure what the 4th way is - combat, maybe?

News Flash (10/27/2013): Website visitor Roger J. wrote to tell the story of how he inherited an unfinished Topper control line model from his uncle. He was kind enough to send a photo of the airframe. Roger intends to complete the build based on the plans shown at the bottom of this page. Hopefully, he will send a photo of the completed model.

"Topper" Article and Plans

Best 4-Way" AYSC Plane

John D'Ottavio

Designer of "Topper"

John D'Ottavio, interested in modeling for over 25 years, has specialized in control-line stunt flying, winning many Eastern contests. His designs have been widely publicized and he is an active member of three N. J. model clubs:

Flyateers (Rich's Hobbytowne), Union M.A.C., and Garden State Circle Burners. As if this doesn't keep him busy enough, he also manages the Roxbury, N. J., Little League! The D'Ottavio's are another modeling family. The older boys, John, Jr. (14), Mickey (12), and Phil (8) are all sprouting model wings while a younger pair, Victor (4) and Donna (2), will soon join the fun.

D'Ottavio's design is a no-nonsense profile stunter. Its built-up wing has a thick symmetrical airfoil and flaps. Tails are sheet balsa. Fuselage is 1/2" sheet with plywood and balsa doublers running full length. Control system is fully enclosed for cleanness. Power was a stock Fox .25, a year old at the time of the Nationals. Any engine up to allowable .35's can be used. Bearer spacing may have to be changed if you shift to a different engine.

Wingspan is 37-in.; length, 31-in.; wing area, 350 sq. in.; weight, 28-oz. Fuel tank is a standard 3-oz wedge; spinner diameter is 1 1/2 in. Top-Flite and Tornado propellers in various sizes were employed for best performance in each flying phase. An 11D-4P prop was used for Endurance; 8D-8P for Speed; 9D-6P for Stunt. Fox Super fuel was in the tank.

Like to build "Topper" for that 1962 AYSC competition? Good! Then read on. Construction starts with the wing since it must be completed before joining to the fuselage. Begin by cutting out the wing ribs. Make one center and one tip rib pattern from thin aluminum, heavy card stock, or 1/16" plywood from the outlines shown on the plan. Note the blank alignment bolt holes near leading and trailing edge. These should be accurately spotted to insure uniform taper of the ribs. Cut 18 rib blanks from 1/16" sheet slightly oversize. Stack 9 blanks between the center and tip rib patterns, drill and bolt together with two 4-40 bolts. Carve and sand the blanks down flush with the patterns. Cut spar and L.E. notches. Repeat procedure to make ribs for the opposite wing half. Notch two center ribs for the 3/16" sq. spar supports and cut out one center rib for bell crank clearance. Also punch 1/4" dia. holes through left half wing ribs for the leadout wires. Locate the hole position by referring to the wing plan. The right wing half is 1" shorter than the left so the tip rib for this side should be discarded and a duplicate of the next to last rib made. This rib should be reduced slightly in outline to maintain taper.

Since the wing is tapered it will be necessary to block up the tip ribs 3/32" above plan and building surface. Cut a couple dozen scrap wedges to aid in blocking up spars and trailing edges during assembly. Build wing UPSIDE DOWN directly over plan. This will permit access to center section for bellcrank and control installation later. Put down upper spar, space out ribs and add leading and trailing edges. Align and block up carefully so that the structure is flat with no twists. Add lower spar and let this assembly dry thoroughly.

Add 1/16" x 1" trailing edge planking and 1/16" sheet leading edge planking. These can be one piece from tip to tip since taper is so slight. Add 1/16" x 1/4" cap strips to ribs. Do not cover center section now. When this assembly is thoroughly dry, it can be taken up from the building board and turned over for additional work. It would be a good idea to block up center and tips on the building board again to prevent twists developing while planking is added to the upper wing surface. Add the 3/16" sq. bellcrank mount support and the plywood bellcrank mount piece. Install bellcrank and leadout wires. Leave bellcrank pivot bolt loose so that flap pushrod can be installed after flaps are assembled. Plank leading and trailing edges and add cap strips to ribs. Here again omit center section planking for the time being.

Make flaps from 3/16" sheet, join with wire type control horn and assemble to trailing edges with fabric "Z" hinges. Add wing tip outlines, contour pieces, leadout guide tubing and right wing ballast. Carve and sand tip pieces to a smooth rounded shape. Now bend the flap pushrod to shape and install. Be sure that bellcrank neutral position gives flap neutral position. When this portion of the control system is completed and working FREELY, the bellcrank pivot bolt can be tightened down permanently and both upper and lower center section planking can be added. Sand entire wing structure smooth and apply two coats of clear fuel-proof dope. Sand lightly again after doping. The wing can be covered now if desired. Silk was used on the original "Topper." Apply silk wet and clear-dope down. Sand lightly between coats with 400 grit wet-dry finishing paper. Build up at least 4 coats of clear dope. Colored dope should be applied after the wing is joined to the fuselage.

Fuselage construction is next. Cut 1/2" x 3" sheet to outline taken from plans. Notch nose for engine bearers and plane thickness taper toward tail. Engine bearer spacing shown on plans is for .15, .19 and .25 engines. Space according to your engine. Make cut-out for wing and elevator pushrod. Add two plywood braces in aft fuselage pushrod slot. These serve to join fuselage sheet and act as fairleads for the pushrod.

Glue hardwood engine bearers in place and cut out the 1/8" plywood nose doublers. Glue the doublers to balsa fuselage sides with white glue such as Elmer's Glue-all. Clamp and let dry thoroughly. Glue the 1/8" sheet balsa doubler to ONE side .of aft fuselage only. At this point in the construction the wing, elevator and elevator pushrod must be installed.

Make horizontal tail surfaces from 3/16" sheet. Join stab and elevators with wire type horn and fabric hinges. Slide wing into fuselage cut-out and pin stabilizer in place. Enlarge wing cut-out carefully to permit passage of flaps through the fuselage. Bend elevator pushrod to shape, slide through plywood fairleads and join to flap and elevator horns. Check for free movement and neutral settings. When pushrod fit is satisfactory, wing and stab glue permanently in place. Align wing and stab squarely with fuselage. Solder retaining washers on pushrod ends at flap and elevator horns for permanent attachment. When thoroughly dry complete the structure.

Additional instructions appear on the full size drawings available from Hobby Helpers as Group Plan # 362A (see firm's advertisement in this issue).

"Topper" Plans

Posted September 28, 2013