DESY 12-123H, DESY-PROC-2013-02 ISBN 978-3-935702-73-7, ISSN 1435-807International audienceWe determine the statistical precision for the forward back asymmetry AtFB in e+e− \to t¯t for the fully hadronic decay mode t¯t \to (bq¯q)(¯bq¯q) at ps = 500 GeV. Results are given for the beam polarisations P(e−, e+) = (−80%, +30%) and P(e−, e+) = (+80%,−30%) for an integrated luminosity of 250 fb−1 for each polarisation. Only signal events are used for the analysis, with overlay. The expected precisions are 2.9% in case of P(e−, e+) = (−80%, +30%) and 3.2% in case of P(e−, e+) = (+80%,−30%)