Sikorsky Aircraft Corporation has received a $435 million US Navy contract to build four production-representative CH-53K helicopters for the US Marine Corps. Designated as system demonstration test articles (SDTA), the four aircraft will enable the Marines to conduct operational evaluation of the new helicopter system in support of Initial Operational Capability in 2019.

“The four SDTA aircraft are based on the configuration of the fourth and final flight test aircraft currently being assembled on the prototype production line,” said Dr Michael Torok, Sikorsky’s CH-53K Program Vice President.

The Navy has included the SDTA helicopters as an additional line item under the existing $3.5 billion system development and demonstration (SDD) contract initially awarded to Sikorsky in April 2006. The contract schedule requires that Sikorsky deliver the first SDTA aircraft in 39 months, and the fourth by the end of March 2017, when the Marines will begin operational evaluation. The contract’s cost-plus-incentive fee arrangement incentivizes Sikorsky to deliver early. Sikorsky will perform final assembly of the SDTA aircraft at the company’s Florida Assembly and Flight Operations facility in West Palm Beach.

Sikorsky has delivered two of the seven SDD CH-53K aircraft—the ground test vehicle and the static test article – into the test programme, and is finalising assembly of the four flight test aircraft and the fatigue test article. First flight of a CH-53K prototype aircraft is expected in late 2014.

Once the SDTA aircraft enter operational evaluation in 2017, the Marine Corps will verify the CH-53K helicopter’s capability to carry 27,000 pounds over 110 nautical miles under “high hot” ambient conditions, nearly tripling the external load carrying capacity of the current CH-53E Super Stallion helicopter.