The helical jet is generated in a tangential pipe nozzle having the tangential and the axial inlets and the axial outlet. The flow directions in free jet spreading in the stationary air was measured by means of a flag type probe. The flow was visualized using the planar scattering technique. It was found that due to asymmetrical distribution of the tangential velocity in the jet leaving the nozzle, the air particles spread in the ambient with various intensity depending on the azimuthal angle. The result is that the jet has a spiral shape with bean-like cross-section.