An aircraft power plant for a fuel cell including a turbo assembly, a compressor assembly, a turbo assembly, a compressor assembly controller, a first stage turbo assembly and compressor assembly operation configured to generate a first stage compressed fluid generated from ambient air and excess oxygen exhausted from a fuel cell of an aircraft power plant. A second stage turbo assembly and compressor assembly operation configured to receive the first stage compressed fluid, and a controller bleed valve coupled with the first stage turbo assembly and compressor assembly and the second stage turbo assembly and compressor assembly. An oxygen supply system, the oxygen supply system fluidically coupled with the first stage turbo assembly and compressor assembly wherein a first compressed oxygen is generated by the first stage turbo assembly is combined with a second compressed oxygen generated by the second stage turbo assembly to generate a combined oxygen controlled by the controller bleed valve. A third stage turbo assembly and compressor assembly operation configured to receive the combined oxygen, and a hydrogen supply system configured to provide hydrogen fluidically coupled with the third stage turbo assembly and compressor assembly.