WASHINGTON – The Pentagon has long discussed the possibility of a bulk order of F-35 joint strike fighters that would span several years and multiple international partners. But now the Department of Defense's top weapons tester is raising concerns about committing to the so-called "block buy" before testing of the aircraft is complete.

The program office has for the past year examined been examining options for a buy that would combine procurement of several lots of Lockheed Martin’s F-35 fighter jet, with the hope of lowering the price tag for US and international customers. In September, Lt. Gen. Chris Bogdan, director of the F-35 Joint Program Office (JPO), hinted that the service was considering pursuing a block buy starting in fiscal year 2018, but has not confirmed the plan.

Depending on the timing of the block buy, US and foreign partners might be expected to commit to purchasing large numbers of the aircraft before operational testing is complete, Michael Gilmore, director of the Pentagon's office of test and evaluation, warned this week in his annual report.

Operational testing, also called initial operational test and evaluation (IOT&E), is a crucial part of any aircraft's development that often unearths technical problems requiring significant modifications to the fleet. In other words, if a problem is discovered during testing, all of the existing aircraft must be opened up and retrofitted to include the fix.

Given the nature of operational testing, Gilmore warned it might not be a good idea to commit to buying large numbers of F-35s before all aircraft have the necessary modifications and are fully combat capable.

"Is it premature to commit to the 'block buy' given that significant discoveries requiring correction before F-35s are used in combat are occurring, and will continue to occur, throughout the remaining developmental and operational testing?" Gilmore wrote. "Is it prudent to further increase substantially the number of aircraft bought that may need modifications to reach full combat capability and service life?"

Gilmore suggested making the block buy, as well as any additional increases in the production rate, contingent upon successful completion of IOT&E. This could provide the program office and contractor "a strong incentive to fix problems and deliver fully combat-capable aircraft," he wrote.

In the report, Gilmore noted concerns with multiple aspects of the F-35's development, from software to cybersecurity to the Autonomic Logistics Information System, the aircraft's integrated maintenance and management system.

Congress is already concerned some aircraft could be delivered without full combat capability. In this year's defense authorization act, lawmakers limited procurement funds for the plane until Air Force Secretary Deborah Lee James certifies that the F-35s delivered in FY-18 will have full combat capability, including the final Block 3F hardware, software and weapons configuration.

If the aircraft are not fully combat capable for the FY18 deliveries, it may be too early to begin ramping up production due to future potential retrofit costs, according to multiple sources. Analysts have also suggested the Air Force will begin leveling off the planned surge in production as soon as FY17 for a different reason: to pay for the service's other modernization priorities, such as the Long Range Strike-Bomber and the KC-46 tanker.

However, the JPO pointed out the F-35 is still in its developmental phase, a time where problems are expected to crop up. The point of testing is to weed out the issues and implement solutions early in order to deliver the best product possible to the war fighter, according to the JPO.

"This is the time when issues are expected to be discovered and solutions are implemented to maximize the F-35's capability for the warfighter," Bogdan wrote in a Feb. 2 statement emailed to Defense News.

"While the development program is 80 percent complete, we recognize there are known deficiencies that must be corrected and there remains the potential for future findings. Our commitment to overcoming challenges is unwavering. The Joint Program Office will continue to work with the F-35 enterprise to make corrections and improvements as quickly as possible. "

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