After outfitting the interior and exterior outfitting of the aircraft, the US-2 looks almost complete. Next, check whether the installed rotor blades and gears are working properly.

The US-2 is based on the design of its predecessor, the US-1A, and has been modified to incorporate the latest theory and technology at the time of its development. For example, in the previous model's control system, the control system and control surfaces such as aileron, rudder, and elevator were directly connected through hydraulic pipes, but in the US-2, movements made by the pilot to the control system were first transmitted through electrical signals. It is controlled by converting the signal into 100% and sending it through electric wires to the actuators that move each control surface. This is called fly by wire. In addition, the engine control is the same, and it is equipped with FADEC (Full Authority Digital Engine Control), which is similar to modern passenger aircraft, greatly reducing the pilot's workload compared to flying boats up to the US-1A.

Once the US-2 has been outfitted, it will be checked at the factory to see if it operates normally before flight tests. The engine cannot be started in the factory, so devices that supply power and hydraulic pressure are connected to the aircraft to actually move the control surfaces and gears (landing gear). He is very serious as he watches the movements of the rudder and gears, making sure not to overlook even the slightest discomfort.

Engine checks are performed in a dedicated area with soundproof walls after rollout (when the aircraft is completed and removed from the factory building).

*Outfitting: The process of installing the engine and equipment inside and outside the aircraft, or the equipment itself.