Wednesday, August 10, 2011

Aeromodeller 1953-04


PERHAPS some explanation as to why the model was built and why it has some particular features is in order. First: we (the author and his wife) spent even' Saturday for some thirteen months working on the real thing. Second : it is of such form that straightforward aeromodclling techniques may be used in.its construction. Third : its aerodynamic set-up is such as to make a free flight scale possible. Built to exact scale in all respects including dihedral in the wing, there are some penalties which wc felt were worth talcing as far as flight is concerned in order to obtain the satisfaction of having an exact scale ship for the judges at the 1952 American Nationals. Two things could be done by the novice to simplify the trimming problems. The dihedral, at rest, could be increased to one inch at each wing tip and the included angle at the empennage could be increased from 90 to 100 degrees- It should be noted that the dihedral specified is at rest, since with the wing attachment used there is, and "in flight," wing deflection of approximately one half-inch. This way we obtained an exact scale plane for the judging but, a slight amount of dihedral for flying. The dihedral tailplanes also add their bit to spiral stability, but, less fin area and more stabilizer area will make a model which is easier to trim.