This work proposes a helicopter pilot model identified from experimental results obtained in piloted simulation flight tests. The tests were originally designed to verify predicted unstable pilot-vehicle systems. The results have been further analyzed using methods for the detection of pilot induced oscillation that are available from the literature. The results show that a pilot-assisted oscillation event occurring in one configuration is characterized by a change of biomechanical properties of the pilot. It is conjectured that such change is triggered by a change in the task of the pilot induced by the specific maneuver that is requested of the pilots in the tests