A collaborative group comprising of the TU Delft, Deltion College and Dutch Electric Aviation Centre aim to develop a flying test bed for sustainable aviation. The collaborative group has acquired a Cessna 337F Skymaster with the intent to replace one of the engines with a retrofit hydrogen internal combustion engine. An ancillary engine will serve as test unit prior to modifying one of the engines of the Cessna 337F Skymaster. Experiments will be performed in a 20-feet container. Hydrogen may leak from a fuel pipe or through a fuel injector from the engine, consequently hydrogen may accumulate in the enclosed testing environment and a detonation occurs. CFD models of the test cell are simulated in ANSYS fluent. One may conclude that heat and hydrogen can be disposed of well, providing an optimal placement of the ventilation system and test cell elements.