The FDR(Flight Data Recorder) records some parameters of an aeroengine.Because of jamming,there is noise error in these parameters.The data must be pretreated so that it can be used to monitor the work condition and performance trends of the aeroengines.The pretreating of rotational speed data of high-pressure and low-pressure rotors with dynamic digital filtering technique are studied.The pretreated data are more continuous and smooth.The development trends of the parameters with flight time can be showed ...