This thesis aims to describe the Flight Path Reconstruction (FPR) process based on flight test data of a new lightweight, multi-purpose helicopter. FPR is a procedure that must be performed during the system identification process to increase the quality of measured data and ensure a more reliable aerodynamic parameter estimation. The thesis aims to determine an error model for several aerodynamic sensors by comparing the measured aerodynamic parameters with the reconstructed flow angles. The first phase of the project involved pre-processing the available flight test data. First, it was necessary to select which signals, among all that were recorded, were of interest to the project.