Tuesday, August 9, 2011

Aeromodeller 1953-02

In view of the water instability inherent in the single front float lay-out, most medium and low-powered models, and most jobs expected to alight back on water, normally employ the three float lay-out in which two front floats provide the main buoyancy members. Since the distance between the outer sides of these floats is anything up to 40 per cent, of the wing span, a fair amount of lateral stability is assured ; by placing the floats in line with (or in front of) the plane of the airscrew, the chances of nosing over during the takeoff or when re-alighting are cut to a minimum. On the debit side there is the possibility of additional drag on the glide and the chance that, should a low-powered model start to swing on take-off, it will pirouette round oil one float until it digs its nose in. In point of fact, the difference in drag between one large float and two smaller ones is negligible ; the increase comes more from the strutting than anything else. Many successful R.O.W. contest models, notably in Russia and eastern states of U.S.A., have used twin front floats, and most power models can easily be converted to use this lay-out without extensive re-trimming being required.