The multi-mission AH-64D Apache helicopter is one of Army aviation’s high demand assets to meet current operations, and a top Army official expects that to continue even as a new model prepares for a production decision.

“We see these requirements continue to grow” in the future, Lt. Gen. James Thurman, deputy Chief of Staff, G-3/5/7, said recently at the Association of the United States Army ILW Army Aviation Symposium and Exhibition in Arlington, Va.

Boeing [BA] has delivered 312 of 382 Apache Block II aircraft, and 54 of those are new builds or war replacements, Thurman said.

Apache Block III, the most advanced version of the helicopter, is expected to have its production review this spring. With a green light and a contract to the company, the first Block III Apache is to roll of the line in October 2011, with the first unit equipped in November 2012, Thurman said.

To meet the rotorcraft demands–and Boeing has a $12 billion backlog–production is ramping up, Mike Burke, director of Business Development for Army Rotorcraft at Boeing, said at a briefing Tuesday ahead of the conference.

For example, in Mesa, Ariz., where Boeing produces Apache helicopters, “we’re starting off pretty quickly with the Block III Apache, which will be a second production line,” he said.

U.S. Apache Program Manager for Boeing Tommy Filler said international Apache Block II customers are now coming in to order more aircraft, which will work out because the company, importantly, has the parts.

Several years ago, Boeing worked hard on the obsolescence issue and the company made a big investment in piece parts, Filler said. “You either make the investment to support your long-range business plan or you’re going to come up short,” he said. “The Block II production line will be open until 2013 and that’s an internal decision for us…Right now, we have firm work out to ’13.”

Col. Shane Openshaw, Army Apache project manager, said everything the service is doing is to sustain Apache aircraft, keep it relevant and mission effective over its lifetime, now expected to reach out “at least” to 2030-2040.

“We’ve got over 600,000 combat hours on Apache to date,” Openshaw said. “That number continues to grow.”

The operational tempo per aircraft in Afghanistan is 70 to 90 hours per airframe in Afghanistan, while it’s coming down in Iraq, as the momentum shifts to Afghanistan.

“The readiness rates are exceptional,” he said.

The Block III Apache completed a Limited User Test (LUT) in November, and while the final report is not complete, the emerging results are positive, Openshaw said. “We exceeded our expectations on what we were looking for in that Limited User Test.”

The final report will inform the milestone production decision review for Apache Block III. The review is expected in April.

Filler said that Block III is the third time the aircraft has been through the facility, once when it’s built as an A model, a second time to convert it to Block I or Block II, and soon back for the Block III configuration.

“I will tell you the international interest in Block III is also strong,” he said. Block III production will likely follow the pattern of Block I and Block II, where international partners go down the line at the same time as U.S. Army production.

“We already have the first international customer lined up to be going down the line with the U.S. Army,” Filler said. While withholding the name of that international Block III customer, it is a substantial buy of some 30 aircraft.