Double Trouble

Owen’s Super Sportster Twin  AKA: Double Trouble

 The pictures shown here are of Owen Dwire’s Super Sportster Twin.  The inspiration for this airplane came from a construction article in R/C Modeler Magazine.  The model is basically a Super Sportster 40 modified to accept two en gines on the wing. 

  Owen had been thinking about taking on the challenge of building and flying an R/C twin for some time.  The impetus to go forward with the project came when he purchased an older Super Sportster kit at a swap meet and got a good deal on an OS .32SX NIB.  (He already had one .32SX powering his ZEN 30).  With the major items in hand there was no reason not to just do it!

  Owen modified the wing by adding 6 inches to the wing span, and replaced the balsa spars with 3/8” square spruce.  He also beefed up the wing center section with 1/8” plywood doublers and extended the center section sheeting to go past the nacelles.   Instead of controlling the ailerons with one servo via rather long torque rods he opted to install a separate servo for each aileron in the outboard portion of each wing panel. 

  The basic design for the nacelles was taken from RCM and modified to fit  Owen’s equipment/preferences.   Instead of using one servo to control both engines via pushrods and bell cranks, he installed a small servo in each nacelle for throttle control.  The resulting nacelles were increased in length and height to accommodate the additional equipment.  Owen also modified the nacelles to accept a removable hatch over the fuel tank in the event maintenance on the fuel tank or servo is required.

  The fuselage was modified as well.  The most obvious mod was to change the nose section to blend in where the engine would be mounted on the unmodified kit.  Owen modified the profile of the nose section from the original to give it a more slender profile.  The rudder and fin area were increased by about 10% to better handle an engine out situation.  A ¾” strip of hard balsa was used on both the fin and rudder to strengthen the hinge line.

  To achieve the proper balance the rudder and elevator servos were placed in the aft end of the fuselage under a removable hatch. 

  Owen elected to use a combination of techniques to finish the model.  The basic structure was covered in yellow Monokote and for contrast the bottom of the wing and stab/elevator was covered with Metallic Red Monokote.  The nacelles were glassed with 3/4oz fiberglass cloth and sprayed with LustreKote yellow paint.  The graphics are of Owen’s own design and manufacture.  He always puts something on the wings of his sport aircraft.

  The overall specs for the airplane:

Wingspan: 62”

Wing Area: 610 sq in.

Weight: 6 lbs 11.8 oz

Wing Loading: 25 oz/sq ft

Power: 2 – OS.32SX with Macs Mufflers

Control: Futaba 9CAP with 4 – S3001 and 2 – S3101 servos

  If you have any questions about the model, Owen can be contacted at vprpilot@cox.net .

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