The present paper reports non-electrically intrusive partial discharge investigations on an aeronautic motor. Relevancy, robustness and repeatability of partial discharge testing procedures, both on insulating materials characterization and on operating aeronautic equipment are essential to ensure reliability of the aircraft systems. The aim of this paper is to be the very first step of defining such procedures and the associated test equipment.To do so, the paper will start by providing an understanding of partial discharge phenomena and will review typical more electrical aircraft architecture. Key characteristics causing partial discharge risk to increase will be highlighted. The impact of harness length, high performance power electronics and voltage level increase on insulation system is demonstrated.Then, an analysis is carried out from motor design perspective to find out which test procedure is relevant to assess each insulation system performance both at atmospheric and reduced pressures. The study helps to realize the benefits of using multiple test sample and procedure to assess insulation system performance level through the design process of the motor. It is shown that a good agreement observed between stator and representative samples.This paper will also review the ability of the non-intrusive test method to detect partial discharge with a full scope of voltage signal from AC to impulse voltage and under different pressures. The paper concludes with an analysis of results and thoughts about future work regarding motor design taking into account partial discharge risk and evolution of proposed procedure.