  We review the orientation of e+e- \to q\bar q g events in terms of the polar
and azimuthal angles of the event plane w.r.t. the electron beam direction. The
asymmetry of the azimuthal-angle distribution is, like the left-right
forward-backward polar-angle asymmetry, sensitive to parity-violating effects
in three-jet events; these are presently being explored experimentally. We
present these observables at O(\alpha_s) in perturbative QCD and discuss their
dependence on longitudinal beam polarisation and c.m. energy. A moments
analysis in terms of the orientation angles allows a more detailed test of QCD
by isolating the independent helicity cross-sections.
