Propeller propulsion unit for an aircraft

A propulsion unit for an aircraft comprising:

• a hollow chassis with an opening in the bottom,
• a propulsion system comprising the following propulsion elements:
• an electric motor with a drive shaft bearing a propeller, a fuel cell providing electrical power to the electric motor, a tank feeding hydrogen gas to the fuel cell, and a cooling system, and
• at least one platform, wherein the at least one platform is fastened to said chassis using fasteners and closes said opening, and
• wherein at least one propulsion element of the propulsion system is fastened to the at least one platform.