The US Naval Air Systems Command’s Sikorsky CH-53K Super Stallion heavy-lift helicopter has successfully completed an initial series of tests to verify its structural strength.
The tests, conducted on a full-size non-flying airframe, static test article, are part of a three-year programme aimed to demonstrate structural integrity of the helicopter and its ability to operate safely over its entire flight envelope, from empty-gross weight of 44,000lb up to its maximum-gross weight of 88,000lb.
Sikorsky CH-53K programme vice-president Mike Torok said: "The static test article will enable Sikorsky to replicate the many stresses, strains and aerodynamic forces the CH-53K helicopter will experience during all aspects of flight, whether the aircraft is empty, filled with cargo, or carrying up to 36,000lb of gear suspended beneath the aircraft by an external sling.
"By placing incrementally heavier static loads on various parts of the airframe assembly, including those well beyond the airframe’s analytical design strength, we can measure structural integrity, airworthiness and crash worthiness, and verify safety margins for all expected operational conditions."
Housed in a specially-built test facility at Sikorsky’s manufacturing plant in Stratford, Connecticut, US, the static test article comprises a 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.
For another two years, it will undergo structural integrity trials to validate the effects of aerodynamic forces and weight distribution on different sections of the airframe.
Sikorsky is developing two non-flying CH-53K test articles, as well as five prototypes and four production-representative heavy lift helicopters for the US Navy as part of a $3.8bn system development and demonstration (SDD) contract.
Image: The CH-53K Static Test Article at Sikorsky’s facility. Photo: © 2014 Sikorsky Aircraft Corporation.