By Marina Malenic

Delivery of new F-35A Joint Strike Fighter aircraft to the Air Force under a revised Pentagon testing and acquisition schedule will come just in time as the service plans to divest itself of aging F-16s, the Air Force’s senior military officer said yesterday.

“It means that we will have less margin with respect to our aging force structure,” Air Force Chief of Staff Gen. Norton Schwartz said during the IFPA-Fletcher national security conference in Washington, D.C., this week. “As opposed to having some overlap between bringing F-35 on in large numbers and when we begin to age out the service life of our existing F-16 fleet, it’s pretty much nose to tail, is how I would describe it.”

Under a risk-reduction effort instituted by top Pentagon weapons buyer Ashton Carter, the F-35 development program will reduce “concurrency” by increasing flight testing and slowing the production timeline, according to Schwartz. The department plans to unveil the details of the plan after the president’s fiscal year 2011 budget proposal is released next month.

“We came to the conclusion that the path we were on was too aggressive,” Schwartz said.

Lockheed Martin [LMT] is developing three F-35 models to replace 13 types of aircraft for the United States Air Force, Marine Corps and Navy, as well as allies including Australia, Canada, Denmark, Italy, the Netherlands, Norway, Turkey and the United Kingdom.

The F-35A model, the conventional take-off and landing (CTOL) variant of the aircraft, is still expected to be ready for initial operational capability with the Air Force in 2013, Schwartz said.

Late last year, the Pentagon acknowledged that its special assessment team once again found that the program faces significant cost increases. The Joint Estimating Team’s latest cost projection for the program has indicated that the $300 billion program may end up costing the government some $16.6 billion more than budgeted. And the latest annual report from the department’s director of Operational Test and Evaluation says that the program continues to face “substantial risk” over the next two years, according to congressional aides briefed on the report earlier this week.

Despite the program’s problems, however, Schwartz dismissed the notion that the F-35 is unusually troubled.

“My sense is this program is far better off than was the case at a similar time for the F-22,” Schwartz said.

Defense Secretary Robert Gates last year decided to cancel additional F-22 production, instead putting all the department’s money on the F-35.

Last week, a leaked Navy analysis report revealed that the F-35C, or carrier variant, would be far more expensive to operate than the sea service’s legacy fighters. Asked whether that analysis raises concerns for the Air Force, Schwartz said he has not yet studied the report in depth.

“The bottom line is that we’re certainly looking at the study, but I don’t accept its findings at face value,” he said.

“If there are issues related to cost of operations, we’ll find remedies and mitigations,” he added. “We have to.”

Other top Pentagon officials at the conference expressed high confidence in the F-35 program. Deputy Secretary of Defense William Lynn said the cost and schedule difficulties it faces are not unusual for a major DoD weapon acquisition.

“I don’t think there’s even been a major defense program–particularly of the technological sophistication of the Joint Strike Fighter–that doesn’t have challenges,” Lynn told Defense Daily on the sidelines of the conference.

Air Force Secretary Michael Donley, the service’s top civilian leader, said Gates remains strongly committed to the program.

“Whatever adjustments, fluctuations, bumps in the road we face, we will get through them to make this a successful program,” Donley said. “It is that important for the department and for the broader national security community and our international partners.”

Asked whether the program is expected to breach a congressionally mandated cost-growth cap this year, Schwartz said he did not believe so.

“I’m not forecasting that that’s in the cards,” he said.