The aim of the research was to determine the possibility of co-combustion of conventional aviation fuel (JET A-1 jet fuel) with hydrogen (H2). The tested miniature turbojet engine was adapted to co-combust of both fuels. The results obtained from the research provide a positive premise for the application and implementation of hydrogen co-combustion (or combustion) technology in aircraft turbojet engines, which has not yet found industrial application. Observations and research show that co-combustion of jet fuel with hydrogen helps reduce the carbon footprint of the use of turbojet aircraft engines and also reduces other harmful substances (e.g. carbon monoxide, nitrogen oxides or solid particles). During the tests, no deterioration of the engine's operating parameters was observed and the set operating parameters were maintained. To summarize, the technology of co-combustion or hydrogen combustion in miniature turbojet engines is an indicated direction in the development of pro-ecological aircraft engines.