The Polytechnic of Turin has started a plan of search for the experimentation of destined cells to combustible hydrogen for the realization of APU (Auxiliary Powr Unit). In particular, the group searches coordinated from the Prof. Paolo Maggiore, delivered up near the Department of Aeronautical Engineering and Spaces them (DIASP), in collaboration with the Energetic Department of (DENER), has placed the objective of the study of new modalities of exploitation of hidrogen, having proposed the analysis of the feasibility of the fuel cells applications to the aerospace field, beginning from the aircrafts for general aviation in order to reach, in a near future, to the case spaces them. DigiSky has been selected like partner in order to carry out the experimentation in flight of the several prototipals units realized with powers that go from a minimum of 100W to a maximum of 5KW. The search, financed from the Piemonte Region, has already allowed to the realization the first prototype, in reduced scale that it has been experimented carrying out the tests with a wide excursion of the flight parameters. The flight campaign has been coordinated from Maurizio Cheli. The first cycle of experimentation in flight, fundamental step of the process of aerospace planning, has been concluded with happening and has allowed to estimate the combined effect of the variation of the environmental conditions them of the atmosphere during the rise in high level and of the maneuvers of the aircraft on the characteristics of operation of the fuel cell.