The Fast Adaptive Bandwidth (FAB) algorithm is a new method that is able to compute in real-time the optimal setting of the loop filters of a GPS receiver in order to minimize the thermal noise on the code or carrier phase measurements. The optimal setting is computed by taking into account of the imposed line of sight dynamics and of the signal to noise ratio of the incoming signals. We will present in this paper any results of the implementation of the FAB algorithm on the carrier tracking loops of a real Gec-Plessey GPS receiver. A high dynamics spacecraft flight scenario has been tested by simulating GPS signals with the GSS 2760 GPS signal simulator. An analysis of the results on the improvement of carrier phase measurement accuracy is proposed.