Despite being on the right path, the F-35’s affordability, or the ability to acquire aircraft in quantity and to sustain them over the life cycle, is of paramount concern, the Government Accountability Office (GAO) said yesterday in a new report.

GAO said in its report, F-35 Joint Strike Fighter: Current Outlook is Improved, but Long-Term Affordability is a Major Concern (GAO-13-309), a new F-35 acquisition baseline that incorporates the Pentagon’s positive restructuring actions taken since 2010 put the aircraft on firmer footing. This new acquisition baseline includes more time and funding for development and deferred procurement of more than 400 jets to future years. GAO also said other restructuring actions, including reduced annual procurements, recognition of concurrency risks and independent cost and software assessments, are steps in the right direction.

But despite the better footing, GAO said the Pentagon and F-35 contractor Lockheed Martin [LMT] need to demonstrate that the F-35 program can “effectively perform” against cost and schedule targets in the new baseline and deliver on promises.

“Until then, it will continue to be difficult for the United States and international partners to confidently plan, prioritize and budget for the future,” GAO said.

GAO said the F-35 program continues to incur financial risk from its plan to procure 289 aircraft for $57.8 billion before completing flight testing.

The F-35 program made “considerable progress” in 2012 on the technical front, GAO said. The program made progress on the helmet mounted display, which encountered significant technical deficiencies and did not meet warfighter requirements. Limited progress was also made in 2012 on development of a smaller, transportable version of the Autonomic Logistics Information System (ALIS), which helps diagnose and predict maintenance and supply issues. The carrier variant F-35C’s arresting hook system was also redesigned in 2012 after the original hook was found to be deficient. GAO said ground testing also made continued progress last year.

GAO warned the critical work to test and verify aircraft design and operational performance for the F-35 is far from complete, with 11.3 percent of the F-35 development contract specifications having been verified so far.