The EC-635 is essentially the same as the EC-135 in terms of combat search and rescue, with the helicopter capable of carrying two stretcher patients and up to three crew members. Different medical equipment is fitted depending on mission requirements. The helicopter is equipped with large side sliding doors and a tail flap hatch. There are also lifting winches, load reflectors and a dual hook system.
The standard EC-635 General Purpose carries one or two pilots and six or seven fully equipped soldiers. The passenger cabin is quick-access and the exit is equipped with a large sliding door. Storage cargo is able to be loaded through a hinged flap door at the rear of the aircraft.
The EC-635 helicopter for surveillance missions can be fitted with a set of underfuselage-mounted surveillance pods with day/night channels, forward-looking infrared instruments, a multi-sensor turret and SX-16 searchlights. It is capable of installing a television and video recording system in the passenger cabin. It is also possible to install cabin doors and observation windows for monitoring operations.