Abstract : The CH-53K helicopter mission is to provide combat assault transport of heavy weapons, equipment, and supplies from sea to support Marine Corps operations ashore. The CH-53K is a new-build design evolution of the existing CH-53E and is expected to maintain the same shipboard footprint, while providing significant lift, reliability, maintainability, and cost-of-ownership improvements. Its major improvements include upgraded engines, redesigned gearboxes, composite rotor blades and rotor system improvements, fly-by-wire flight controls, a fully integrated glass cockpit, improved cargo handling and capacity, and survivability and force protection enhancements. It is expected to be able to transport external loads totaling 27,000 pounds over a range of 110 nautical miles under highhot conditions without refueling and to fulfill land- and sea-based heavylift requirements. Background Sikorsky was awarded a sole-source contract to develop the CH-53K helicopter because, according to the program office, as the developer of the CH-53E, it is the only known qualified source with the ability to design, develop, and produce the required CH-53 variant. The program entered the system development and demonstration phase of the acquisition process in December 2005 and a $3 billion development contract was awarded to Sikorsky in April 2006. Beginning in 2006, the program experienced schedule delays that resulted in cost increases to the development contract. As a result of the schedule delays and cost growth, in 2009 the program office reported a cost and schedule deviation to its original cost and acquisition program baselines to OSD. However, these increases were not significant enough to incur what is commonly referred to as a Nunn- McCurdy breach.