A method and system for acquiring aircraft parameters that includes sampling an aircraft parameter during a first sampling period, recording the full value of the aircraft parameter sampled during the first sampling period, then sampling the aircraft parameter during a fixed number of subsequent consecutive sampling periods, and recording the change between the value of the aircraft parameter sampled in the subsequent sampling periods and the value of the aircraft parameter sampled in the prior sampling period. A method and system for constructing a data stream that includes merging a voluntary data stream and the mandatory parameters and storing the merged data stream in a flight data recorder while maintaining the certification of the flight data recorder.