CERN-SPS. Measurement of LAMBDABAR polarization in NUMU charged current interactions by the NOMAD collaboration using a wide band neutrino beam with mean energy 43.8 GeV. The data sample consists of 649 reconstructed LAMBDABARs. The longitudinal axis is chosen along the reconstructed W-boson direction. The transverse axis is orthogonal to the LAMBDABAR production plane and the z axis forms a right handed co-ordinate system with the other two. Note that the Feynman X variable, xF,is coded here as XL.