This research investigated the combination of a fuel cell and ultracapacitors to create a hybrid powertrain for a vertical take-off unmanned aerial system (UAS). This replaced the more common battery-only powertrain or the hybrid fuel cell-battery powertrain. A secondary power source, such as a battery or ultracapacitors, is required to assist a fuel cell with immediate load requests because fuel cells are unable to supply instantaneous power. The fuel cell-ultracapacitor was tested using a power profile that was experimentally determined using a battery-powered vertical take-off UAS during take-off, hover, and landing. This tabletop experiment is meant to lead to a more refined solution that can be easily scaled to fit into a smaller future vertical take-off UAS. Two separate ultracapacitor banks were made to be put in parallel with the fuel cell. The first was a series of 14, 650 Farad ultracapacitors and the second was a series of 14, 350 Farad ultracapacitors. Both fuel cell-ultracapacitor powertrains were able to meet the power requirements while also supplying power to the fuel cell itself, without an external power supply. Future work opportunities include scaling for implementation into a UAS platform and coding the power management software to optimally manage the proposed hybrid powertrain.