Boomer Bus (oz12252)
About this Plan
Boomer Bus. Free flight power model. Wingspan 54 in, wing area 380 sq in. For Bantam or Ohlsson .19 engine.
Note this design was later redrawn by Al Patterson in MB September 1981, see Boomer Bus (oz4951).
Direct submission to Outerzone.
Update 10/06/2020: Added article, thanks to RFJ.
Quote: "Boomer Bus, by Henry Struck.
Modeled after the superefficient Bowlus Baby Albatross sailplane, this ship will be of especial interest to those who have grown tired of the conventional model. However, in spite of its unusual appearance the Boomer Bus possesses the stability, efficiency, and accessibility necessary for a contest flier.
The wing area of a model powered by a Class B engine (.2 to .3 cubic-inch displacement) falls between two and three square feet if the lightest possible wing and power loading is to be observed. Accordingly the 380-square-inch wing area of the Boomer Bus places it just about midway between either extreme, permitting the use of any Class B engine. If desired, the new Bantam or Ohlsson 19 may be installed and the ship will give a good account of itself in Class A competition.
In effect the gull wing is a form of parasol, which, when coupled with a rudder of ample size to compensate for the absence of fuselage side area, solves the problem of spiral stability, allowing adjustment for the circling flight needed for soaring.
The construction of the ship is sturdy, but makes for easy repairs in case of damage. Though the average modeler will find little trouble in building the model, he may omit the fuselage fillets and straighten out the gulled section without matrrially affecting the performance. The wing and tail are quickly removable for transportation, while the engine unit is removable for easy servicing.
Extensive flight tests have proven this twenty-two-ounce job to be a real competitor. On a twenty-second motor run the duration is over two minutes in calm air, with the model capable of taking advantage of even the slightest riser to increase the time.
FUSELAGE: (Plate 1) It is best to begin work by making the boom first to allow construction to continue uninterrupted while the blank is drying. Select a sheet of straight-grained medium-hard 1/8 sheet balsa, cut it to the size required for the boom blank and soak it thoroughly in hot water. Mold it carefully around a straight length of broomstick or rod of similar diameter and wrap it with cloth bandage to hold it while drying. The wood may be baked slightly to hasten drying, although the safest way is to set the stick aside for about twenty-four hours and work on the fuselage, or pod.
The pod, although planked, is so short it offers little difficulty. Trace the bulkhead sections given in full size on 1/8 sheet balsa and assemble to form the bulkheads. Cement the bulkheads on the longerons of 1/8 square. Begin planking by cementing strips of 1/8 x 5/16 soft balsa over each longeron. Attach two or three side planks and form the motor-mount retainers of bicycle spokes and cement them solidly in the body. Plank the rest of the pod, trimming the strips wherever necessary to get a good fit.
Cut out the front bulkhead N from 1/16 plywood and cement it to the nose. A block of soft balsa is glued to the rear of the pod and carved to carry out the contours of the fuselage. Smooth the planking with rough sandpaper or by careful use of a knife. Finish the pod with successively finer grades of sandpaper, polishing with 10 naught.
Remove the boom blank from the form and cement the keel of 3/16 sheet in it. Cement a plug of soft balsa to the rear and carve to shape. Sandpaper the boom smooth and cut away the bottom of the front portion to fit the top of the pod. Use plenty of cement at this junction and check the alignment carefully. A wedge of 1/8 sheet between the boom and the pod will fur-ther strengthen the assembly.
Cut the wing and tail rests from 1/8 sheet. These are of approximate streamline outline, but their exact shape is rela-tively unimportant. Cut away the top of the boom and fit them in place, maintaining the incidence angles established by the keel blank. Cut the bottom fin from 1/8 sheet balsa and cement it to the boom..."
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