Article Date: February 1992
My premise of a fixed vertical fin with horizontal stabilizers on the prop thrust line, along with a tapered rudder is valid. My execution of this idea went a bit overboard – the “keep it simple stupid” acronym would have come in handy. Most of you will see that by this first line – The foam was 2 inch urethane (should have been 1 inch thick).
The glass cover was 8 oz. instead of 4 oz. per yard. The second layer of “glass” should have 1.5 oz. instead of mat. The horizontal stab should have been built in one piece instead of two and the vertical fin should have been two-piece.
The leading and trailing edges of all surfaces should be PVC pipe sawed lengthwise in the appropriate O.D. – (1 inch for fin and rudder – 3/4 inch for the horizontal stabilizer). Wooden dowels of 1/8 inch instead of 1/4 should be used to pin all pieces together along with Elmer’s woodworking glue. All of the other hardware was what I had on hand.
Some must-have items: Shurform pocket rasp, one oz. measuring cups, sharp scissors and knife, dust filter masks and latex gloves, a 4 x 8 foot workbench, vacuum, ventilation, sander(s), and sandpaper (medium through fine), three or four 1 inch bristle paint brushes, polyethylene mixing containers (one lb. margarine tubs – clean), two 4 inch polyethylene squeegees.
Fiberglass supplies are: 4 yards x 38 inches wide, 4 oz. bi-directional cloth, 4 yards of 1.5 oz. bi-directional cloth, and 1 lb. of 3M glass bubbles (micro-balloons) for fill. Also 1 qt. of polyester laminating resin, 1 qt. of finishing resin, 2 oz. of MEKP catalyst (use at 8 drops per ounce of resin); and, one quart of Acetone.
Two weeks later you realize that an all metal tail would have been lighter, easier to make, just as durable, and with the option of polishing or painting! To sum it up – some projects are a learning experience that allows one to do better next time. That’s also why there is an EXPERIMENTAL license on the flying Phantom.
Building in composites definitely has its place in aviation, but it can be very unforgiving – in both manufacturing and design. For the inexperienced, metal can be more forgiving, easier to handle, and with some thought – give similar flexibility to your design ideas. While I’m flying the fin/rudder combo, I will not build the next one the same way.
The design will be produced in metal frames and aluminum skins in an easily shippable design. Look at the accompanying photos for the “during” and “finished” comparisons. From these you may get your own ideas for a highly controllable “tall tail” combo with your stock Bensen mast.
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