Efficiency of the Raked Wing Tip.
In the previous chapter mention was made of the probable gain in efficiency resulting from the raked wing tip, and that this has some foundation in fact will be apparent from a consideration of [Fig. 39], which illustrates the flow of air across a plane, as generally accepted. Where the plane surface is continuous from wing tip to wing tip, the provision of the shaped tip would appear to compensate for any slight loss, but there are instances where the extent of the pilot’s range of view is of the utmost importance, and this may necessitate the cutting away of a portion of the centre section (which sometimes affords the only means of ingress and egress), or the root of the lower plane, as in [Fig. 40].
Fig. 39.—Diagram showing flow of air across plane.
CENTRE SECTION CUT AWAY
SPAR ROOTS CUT AWAY
Fig. 40.