This paper presents the comparison of results obtained from two codes with different degrees of accuracy and computational time on the case of a contra-rotating open rotor (AI-PX7). The main goal is to assess the capacity of a code based on singularity methods to predict global open rotor performance, the in-plane loads (also called 1P loads), and the blade load distribution during a full blade cycle. Moreover, installation and unsteady correction models have been implemented in this code in order to evaluate the possible improvements of initial predictions. Finally, a numerical method to quantify some of the mechanisms governing open rotor thrust and 1P loads is proposed.