In order to prove the design validity of SST flight control and hydraulics systems prior to flight, the systems will be assembled and operated in testing fixtures under simulated operating loads and expected flight environments. Clearance for first flight will depend upon successful demonstration in the testing complex.
The program is named CODE (from controls DEvelopment), and for the prototype airplane it is divided into two stages. Initially, component problems will be studied in a Preliminary CODE fixture using a triple-channel conceptual servo actuator under mechanical and electrical command. This Preliminary CODE will allow for variation in load inertia, simulated aerodynamic load, and in the compliance used to represent the flexible airframe. Flutter loads will be generated by an external force servomechanism. Data from the Preliminary CODE program will guide design of flight hardware for the prototype airplane.
The second or Prototype CODE stage will utilize flight hardware in a fixture which spatially resembles the prototype airplane. Prototype CODE development studies will emphasize dynamics within the hydraulic, flight control, and automatic flight control systems. Interaction effects among these systems will be studied under all expected conditions of dynamic pressure, flutter, and elevated temperature environment. In both Preliminary and Prototype CODE, analog and hybrid computers will simulate airplane dynamics.