The Army plans to release a request for proposals early next year for CH-47F Block 2, which will allow the service to operate the helicopter more affordably as it ages—an investment the service sees as critical, as it will be in the fleet until at least 2060.

The Block 2 changes “will let them buy back some performance, specifically payload,” Col. Rob Barrie, Army program manager for cargo helicopters, said Monday during a briefing at the Association of the U.S. Army annual meeting and symposium. Block 2 is not yet a program of record, but an advanced rotor blade made of composite materials, new drive train and new fuel cells will likely be introduced into the aircraft.

The service also wants to use it as an opportunity to make the conventional Army Chinook more common with the special operations variant, the CH-47G, he said.

Milestone B and a contract award—presumably to original equipment manufacturer Boeing [BA]—is scheduled for fiscal year 2017. After that, a four-year engineering and manufacturing development phase would begin, with low rate initial production set for 2021.

Block 2 preparations currently are funded through a budget line for engineering change proposals, which are relatively consistent year to year, Barrie said. However, budget instability, including sequestration or a longterm continuing resolution, could impact Block 2. “There may be challenges that we can’t see right now,” he said.

“The RFP release, we’re proceeding toward that. It’s in the very near future, and there are no plans to change that now,” he said. “That’s as good as the budget realities we have today. It will have to be reexamined if there are any changes, whether that’s sequestration or a CR.”

Instead of taking care of upgrades piecemeal through traditional engineering change proposals, the Army decided to group them together and do them along with planned recapitalization of older CH-47F models to save money, Barrie said.

Steve Parker, Boeing’s vice president of cargo helicopters, said the company had made “significant investments” in research and development funds to mature potential Block 2 technologies, such as developing a new type of steel, but he declined to specify the amount of the investment.

There have been more than 340 deliveries of CH-47 F model, Barrie said.

The company recently finalized a sale to India—the 16th Chinook customer— for 15 “F” models and is looking for additional international buyers for the aircraft, Parker said. He predicts Boeing could sell more than 150 helicopters to foreign customers between now and 2020. Production of the aircraft could extend “well into the 2030s.”

The current multiyear contract, which wraps up in 2017, contains 30 remaining options for foreign military sales, Barrie said. “I think it’s safe to say that we anticipate we will exhaust those those 30 options in the remaining two years of procurement that we have.”