Abstract: For a premature breakdown of a wing vortex pair +/−&Ggr;M behind an aircraft in flight (1) comprising a symmetry plane (7), two wings (3), a fuselage (2) and a horizontal tail plane (HTP) (4), the wing vortex pair +/−&Ggr;M being generated in the area of the tips of the wings (3), having a first spin direction and descending behind the aircraft, an interfering vortex pair −/+&Ggr;P, which is generated between the fuselage (2) and the tips of the wings (3) without merging already in the near field behind the wing (3) with the wing vortex pair +/−&Ggr;M and which has a second spin direction that is opposed to the first spin direction, is retained behind the aircraft (1) in an altitude range of the wing vortices of the wing vortex pair +/−&Ggr;M by adjusting to suitable values the relative circulation and the relative span of the interfering vortex pairs −/+&Ggr;P, each related to the wing vortex pair +/−&Ggr;M.

Abstract: The invention concerns the use of working bodies of low density in vibratory abrasive finishing machines for the smoothing of articles of wood, particularly articles of furniture, between the undercoating and varnishing thereof. The working bodies have either the shape of angular resin-free wooden pins of a size of 4.times.4.times.30 mm and an average Shore A hardness of about 95.degree. to 100.degree. or a flat base opposite which there is a head surface corresponding to the shape of a spherical segment.