Mini-Fledgling (oz3937)

About this Plan

Mini Fledgling. Radio control model. Sterling plan. Kit FS-35. 40in span. Recommended engine .049 or .051 with 2 channel R/C on ailerons and elevator.

Quote: "The New Mini-Fledgling. For Beginners or Experts. If you've seen of flown our Fledgling (oz4117) it will give you an idea of the great performance you can expect from its little brother. Maintaining top quality and simple construction, all balsa and plywood parts are accurately die-cut including full-length fuselage sides. Includes R/C hardware, decals full size step by step plans. Recommended engines .049 or .051 and 2 channel R/C, although other suitable equipment may be used."

Ad copy shown in morepics 004 is from Model Builder, August 1977.

Update 13/04/2020: Added kit review from RCM June 1980, thanks to RFJ.

Quote: "RCM Product Review: Sterling Models Inc. MINI-FLEDGLING.

The Mini-Fledgling is designed for the beginner and for general fun flying. It is a shoulder wing airplane requiring two channels for either rudder and elevator or ailerons and elevator. Ailerons and elevator is recommended on the plans because more flight maneuvers can be performed with that configuration. The recommended set-up is all right for the beginner except it must be hand launched.

A full color label showing two views of the completed model appears on the cover of the 29.5 x 5.25 x 2 in box.

All the necessary hardware required to complete the Mini-Fledgling was contained in a plastic bag with the exception of the pre-bent wire landing gear. The die-cut wood pieces are marked for easy identification, and the rest of the unmarked wood was stacked loosely in the box.

Construction: The full size plans and all the instructions for building the model are printed on both sides of a 23 x 35 in sheet. Two photographs appear on the plans, showing the model both sans covering and with covering and trim. The drawings are good and the instructions are more than what most moLlers, including beginners, would read. We feel that both the design and instructions could have been simplified especially for the beginner.

The die-cutting was good, the wood was not smashed and parts were relatively easy to separate from the sheets. The machine cut hardwood engine blocks did not quite match the plans. The overall quality of the balsa wood was good, but the die-cut balsa stabilizer was replaced, because of the quality and thinness of the balsa.

Overall, the parts fit well. The fuselage has cowl cheeks that trap the engine exhaust and may affect the performance of the engine. The trapped exhaust and excess fuel is funneled directly into the hole in the firewall where the fuel lines come out from the tank/battery compartment. The exhaust suck also can seep under the compartment's hatch cover and into the compartment; therefore, it is recommended that the compartment be sealed with RTV Silicone, which sticks well to both the fuel lines and covering material. (Put a thin film of petroleum jelly on the hatch cover before applying the RTV Silicone. This will allow the easy removal of the hatch cover should it be necessary.) It might also be worthwhile to carve away a portion of the cowl cheeks to clear the exhaust path.

The partially (top and bottom) sheeted wing is attached to the fuselage at the leading edge by two dowels and a nylon screw at the trailing edge. The dowels are inserted through a plywood plate on the wing and screwed into a pre-tapped piece of hardwood epoxied to the fuselage. All of the above is supported by the wire landing gear with 2" DuBro wheels (not included in kit). This landing gear is strong enough to handle less than perfect touch downs. If the landings are a little 'hard' the gear will give you another chance to make a decent landing, that is, it'll re-launch the plane into the air for that second or third touch down.

All gluing was done with Gluit, and the engine compartment was sealed with Sig epoxy. It would be a good idea to seal the fuel tank/battery compartment with epoxy too. Epoxy was used with nylon tape to reinforce the center section of the wing.

Covering: Silver, orange, and black Kwikote was used to cover the model. The trim consisted of black and white trim tape.

Engine: A Cox TD .049 engine complete with 1-1/2 in Goldberg spinner and 6/3 Cox gray prop was attached to the hardwood motor mount. Directly behind the engine is the fuel tank/battery compartment. Powered flights of 10-12 minutes may be achieved by using a Pylon brand 2 ounce cylindrical fuel tank.

Radio: A 3-channel EK Ranger radio system was squeezed into this model. The beginning modeler will find the Mini-Fledgling a bit tight or just too small for some of the popular R/C gear. A custom built 225ma battery pack was made to fit under the fuel tank so as to be able to squeeze in all the necessary R/C goodies and to achieve the proper balance without adding weights. The aileron configuration makes less efficient use of the space available for the R/C gear. Only minimal space is available for the R/C gear, which does not leave much room for the foam so necessary to protect the gear from vibration and other shocks encountered by many a beginner's airplane.

Flying: This Mini-Fledgling was built with ailerons and half the recommended dihedral to improve the roll characteristic of the airplane. The airplane's stability didn't seem to suffer from the reduced dihedral and it rolls well. Other than the dihedral. everything was built according to the plans. The first flight was flown with the transmitter trim set to neutral. It has been flying that way without any adjustments since. The Mini-Fledgling does all the basic maneuvers, loops, rolls, inverted flight, etc, but it doesn't spin. Hand launching is a cinch, just a slight forward motion of the arm with the model level and off she goes. The thick wing provides nice long glides when the power quits, the ailerons proved effective at moderate speeds. Landings are no problem.

ven though this model weighs 2 ounces more than the recommended weight, the Cox TD .049 provided enough power to pull it through maneuvers expected from this type of model. It even thermals pretty well.

The Mini-Fledgling certainly does do the job it was designed for. The Mini-Fledgling was supposedly designed for the beginner, but it requires more work to build than a small beginners plane should. Once it is built, you'll find that it is super strong. The wing seems like it was carved from a board and should be able to withstand any flight stress short of an abrupt halt upon contact with the ground. The rest of the plane is almost as strong. If the plane is built correctly, because of its sturdiness, the beginner will have a good R/C airplane to learn to fly with. On the other hand, if he should crunch it a bit, the repair job will be more difficult than it should be for a beginner's airplane. In fact, if the plane is completed correctly, the beginner will have gained enough building experience to tackle any model designed for the intermediate R/C modeler."

Supplementary file notes

Review.

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