The U.S. Marine Corps is preparing for the first flight of its next-generation CH-53K heavy lift helicopter, an aircraft acquisition program which is four years behind its original schedule.

The “K” model CH-53 is being engineered to provide more lift, speed, performance and protection compared to prior models.

The CH-53K, now being developed through a $435 million deal with Sikorsky from May of this year awarded by Naval Air Systems Command, is slated to take its first flight in the middle to late part of 2014. The contract calls for the construction of four test vehicles which are currently being developed at a Marine Corps facility in Palm Beach, Fla.

The more recent deal is an additional contract line item under a $3.5 billion System Development and Demonstration contract with Sikorsky in 2006, lining up development of the CH-53K.

The CH-53 K program is planning to enter Low-Rate-Initial-Production in 2016 and reach Initial Operating Capability by 2019, said Col. Robert Pridgen, heavy lift helicopters program manager, NAVAIR.

The program office says they are on track after an April 2011 Government Accountability Office report on the program raised concerns about cost growth and schedule delays with the CH-53K.

The report, titled, “CH-53K Helicopter Program has Addressed Early Difficulties and Adopted Strategies to Address Future Risks,” credits the program for implementing strategies to delay production and increase developmental funding but cites a history of problematic cost growth for the effort.

The report cites $6.8 billion in cost growth due to increasing quantities and efforts to begin development prior to determining how requirements can be achieved. Furthermore, the report says that program challenges wound up delaying the sought after production timeline by as much as three years. Since the time of this report, the IOC for the helicopter has slipped another year to 2019, resulting in an overall delay of up to four years.

At the same time, in order to meet operational demand for the CH-53 mission, the Marine Corps wound up bringing old airframes back from retirement in 2010 at a cost of $2.8 million each. CH-53E airframes were taken from an Airzona desert “boneyard” and refurbished to meet wartime needs, since the production lines for the helos ended in the late 90s.

Meanwhile, CH-53 K program officials told the GAO as recently as this past March that helicopter design was sound and that the program is on track to meet all the requirements.

The idea with the helicopter is to engineer a new aircraft with much greater performance and three-times the lift capacity compared to the existing CH-53 E or “Echo” model aircraft designed in the 80’s, said Pridgen.

“The requirement is to be able to lift 27,000 pounds, take it 110 nautical miles, stay 30 minutes on station and then be able to return to a ship under high hot conditions. If I were to try to do that today, the best the “Echo” could do is 9,000 pounds,” Pridgen said.

Higher temperatures and higher altitudes create a circumstance wherein the decreased air-pressure makes it more difficult for helicopters to fly and carry payloads.

Pridgen explained that the requirement for the “K” model CH-53 emerged out of a Marine Corps study which looked at the combat aviation elements of a Marine Air-Ground Task Force, or MAGTF.

“We recognized that the mission had evolved and that the national security strategy had said that the mission had changed such that more lift was required. And the requirement for heavy lift needed to be affordable in terms of sustaining it. Out of that requirement the ”K” was born; The K requirement not only make it able to lift a lot more and take it a long way — but also to make this thing a lot easier to maintain,” he said.

Engineers with the “K” program are using a handful of new technologies to achieve greater lift, speed and performance with the helicopter, including the integration of a new, more powerful GE 38 turboshaft engine for the aircraft, developers explained.

“Fuel consumption of the engine is 25-percent improved. On a pure technology level it is about a 25-percent improvement in fuel efficiency,” said Dr. Michael Torok, Sikorsky’s CH-53K program vice president.

The helicopter is also being built with lighter-weight composite materials for the airframe and the rotorblades, materials able to equal or exceed the performance of traditional metals at a much lighter weight, said Torok.

“Technology allowed us to design a largely all-composite skinned airframe. There are some primary frames titanium and aluminum. Beam structure and all the skins are all composite. Fourth generation rotorblades are a combination of new airfoils, taper and a modification of the tip deflection of the blade. It is an integrated cuff and the tip geometries are modified to get additional performance,” Torok said.

The helicopter will also be configured with Directional Infrared Countermeasures, or DIRCM, a high-tech laser-jammer designed to throw incoming missiles off course.

Also, the CH-53 K will be using what Torok referred to as a split-torque transmission design that transfers high-power, high-speed engine output to lower-speed, high-torque rotor drive in a weight efficient manner.

The K model will be a “fly by wire” capable helicopter and also use the latest in what’s called conditioned-based maintenance, a method wherein diagnostic sensors are put in place to monitor systems on the aircraft in order to better predict and avert points of mechanical failure, Pridgen explained.

“There’s an opportunity to learn about the aircraft and be much more predictive,” he said.