Sikorsky Aircraft has completed the initial series of tests required by the U.S. Naval Air Systems Command to verify the structural strength of the heavylift CH-53K. Conducted on a full-size non-flying airframe called the Static Test Article (STA), the tests are part of a three-year program to validate that the largest helicopter ever designed and built by Sikorsky has the structural integrity to operate safely over its entire flight envelope — from its empty gross weight of 44,000 pounds up to its maximum gross weight of 88,000 pounds with external load.
The STA is housed in a specially-built test facility at Sikorsky’s manufacturing plant in Stratford, Conn. Consisting of the cockpit, the cabin, fuel sponsons, a transition section and the tail rotor pylon, the complete airframe assembly is suspended off the ground by the shaft of its main rotor gearbox. Surrounding support beams hold the numerous hydraulic cylinders that apply the flight and inertial loads to parts of the airframe assembly. Also attached to the STA structure are component-representative weights that simulate the presence of the engines and landing gear, among other key subsystems and components.