In this work, the behavior of the electrical insulation system of an aeronautical tape wound PTFE power cable in presence of partial discharges (PDs) was investigated in terms of time to failure as a function of the characteristics of an AC applied voltage. The electrical insulation of specimens was submitted to an intense electric field by applying voltage to the conductor, while a grounded metallic braid covered the outer surface of the insulation. An AC mean frequency (14-56 kHz) voltage was set above partial discharge inception voltage (PDIV) of the cable. Aging with PDs was carried out at constant voltage amplitude. For each voltage frequency, seven specimens were tested. Time to failure (dielectric breakdown) for each specimen was recorded and different parameters such as surface temperature and dissipated discharge power were measured during the ageing.