The F-35 is even further behind schedule and more over budget than other watchdog agencies have reported. A new Government Accountability Office (GAO) report finds the troubled program will need an additional $1.7 billion and another year just to finish its already 16-year-long production process.

The GAO echoed much of the information released by the Pentagon’s top weapon testing office earlier this year, but painted an even bleaker picture of the future of the most expensive weapon program in history. The F-35 Joint Program Office recently admitted it would cost $532 million beyond current budget levels to complete the development process. The Pentagon’s Cost Assessment and Program Evaluation (CAPE) office estimated it would cost about twice that amount—$1.125 billion. The GAO now says the task will take $1.7 billion.

The GAO based the new figure on an analysis of the F-35’s flight test data to date. The reported problems thus far have been uncovered during the comparatively easy part of the testing process. The difficult testing is about to begin, and more problems are likely to be uncovered—meaning the program is likely going to cost even more.

The challenge now is the flight tests of the final, and most complicated, version of the F-35’s mission software. This is what controls every input the pilot receives regarding threats, targets, weapons, and the mission profile to be flown. If and when it works, it is, together with stealth, intended to give the F-35 the biggest advantage over all current fighters. The contractor released what is supposed to be the final version of the software in November 2016. The only way to tell whether the software, which has been bedeviled with bugs over the years, is complete, is to test it point by point in the air.

The program office claims it will be able to complete these flight tests by October 2017. The history of the program’s testing calls this claim into question, though: the most recent publicly available testing report showed the program was only able to accomplish 82 percent of the planned mission system test points in 2016, 975 of 1,189 planned, or about 83 per month. According to the GAO, the program would have to complete an average of 384 mission system test points a month to meet the October 2017 completion date, quintuple the current, demonstrated rate. The GAO determined this is something the F-35 program is unlikely to accomplish.

Even these planned test points represent only a portion of the total testing program. During the planned tests, the teams often encounter unanticipated problems that cause them to add additional tests to fix the deficiencies they find. This certainly occurred in 2016: officials were required to add 1,784 development and regression test points.

Based on this information, GAO estimates the F-35 program will not complete developmental testing until May 2018. Because time is money, the program will require extra money in order to fund the process through the delay.

As bad as this news is for the program, there is reason to believe the GAO is being conservative in its estimate. Not addressed in this report is the simple fact that the remaining tests are the most complicated in the entire process. These include the critical Weapons Delivery Accuracy tests, which are important because rather than just testing to make sure an individual component functions properly, they test the entire kill chain, “the complete find-fix-identification (ID)-track-target-engage-assess-kill chain for air-to-air and air-to-ground mission success.” This means the tests will see if a pilot can locate and properly identify a target, hit it with the right weapon, and then tell if the target has been destroyed—just the sort of thing a pilot would have to do to be effective in combat.

Several of these tests involve multiple aircraft flying together. Because the program has been having trouble reliably keeping F-35’s flightworthy, any testing involving more than one aircraft can prove difficult. The test fleet requires an availability rate of 80 percent for an efficient test program; anything less than that risks delaying the completion of testing. The current test fleet based at Edwards Airforce Base in California had an availability rate of only 48 percent during the first 9 months of 2016. For this reason alone, the GAO estimate of an additional year and $1.7 billion to complete development is likely low. By dividing the number of additional months the GAO estimates it will take to complete development—12—by the amount of additional funds the office estimates will be required, it can safely be assumed that taxpayers will have to spend at least $141 million every month this process continues.

In the annual testing report, DOT&E also estimated a May 2018 developmental completion date for the current software version. This, like the GAO estimate was based on the F-35 completion rate up to this point. But DOT&E cautioned that significant new discoveries are likely during the remaining test process of the more complicated systems. This could require the program to release new software versions. Each new version would require the program to reset the testing process to confirm earlier results. This would add yet more months onto the process, each of which is costing taxpayers $141 million. Because there are so many unknowns, determining a truly accurate estimate of future costs is difficult.

Delays in developmental testing threaten the beginning of the crucial realistic combat testing, or operational testing, phase of the program. This is the process where teams test the aircraft not just to see if it performs up to technical specifications in what is essentially laboratory conditions, but to see if the entire system is both effective and suitable for combat in the hands of actual warfighters.

The F-35 Program Office claims it will be able to begin combat testing in February 2018. But the GAO reiterated DOT&E’s estimate that this process is unlikely to begin any earlier than the end of 2018, and states early 2019 is a more realistic estimate.

Pushing back this process can have a cascading effect on future decisions, according to the GAO. First is the impending Initial Operational Capability declaration by the Navy. This is anticipated to occur in February 2019 but this date hinged on the completion of the combat testing process.

Second, but of more immediate concern, are impending decisions to increase F-35 production. The F-35 program office and Lockheed Martin continue in their efforts to secure a “block buy” of 452 additional aircraft. Although they now seem to be attempting to fool the public about their intentions by saying they just want to purchase two years’ worth of aircraft parts and calling it an Economic Order Quantity (EOQ) purchase. The program office is expected to request $650 million in 2018 for an EOQ. They claim this upfront investment will save money in the long term. But GAO cautions that “with cost growth and schedule delays facing the F-35 baseline development program, it is unclear whether DOD can afford to fund this effort at this time.

The GAO report also raises serious concerns about the Pentagon’s plans to push forward with the F-35 Follow-On Modernization program, otherwise known as Block 4. F-35 officials have announced their plans to award a contract for the Block 4 development to add even more capabilities to the F-35. This is expected to cost $600 million in 2018. The problem with this plan is the Pentagon has no idea now what it has to modernize on the F-35 because it hasn’t finished developing the initial design. Without completing that process, the Pentagon does not have enough information to create a list of requirements for the updated design, which makes it impossible for contracting officials to create an executable business plan for the new program with accurate cost and funding estimates. The GAO warns:

“Early Block 4 requirements, which represent new capabilities beyond the original requirements, may not be fully informed before DOD plans to solicit proposals from contractors for how they might meet the government’s requirements—a process known as request for proposal (RFP). According to DOD policy, the Development RFP Release Decision Point is the point at which a solid business case is formed for a new development program.”

This latest report is further proof that the F-35 is a truly troubled program. Unless officials make the tough choices now, the men and women who will have to take the jet into combat will do so in an aircraft that has not been fully developed. At the very least at this point, the Pentagon must complete the development process and put the program through a rigorous combat testing process. Only through such means will anyone be able to make an informed decision about further F-35 purchases. It is the only way the American people will know whether the tens of billions spent already on this program have been invested wisely.

Dan Grazier is the Jack Shanahan Fellow at the Project On Government Oversight, where this first appeared.

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