Championing Responsible National Security Policy

Is the F-35 Program at a Crossroads?

As official support for the F-35 program wanes, the Pentagon’s largest weapon program is struggling to show it has the promised high-end capabilities for which taxpayers are paying a premium.
(Illustration: Renzo Velez / POGO)

Pentagon leaders had expected 2020 to be a big year for the $1.727 trillion F-35 program. The long-anticipated full-rate production decision that would have allowed the F-35 to move beyond testing and development and into mass production was scheduled to be made by 2020. Coronavirus-related travel restrictions hindered some development fixes in 2020, but any such impacts were minor compared to the many long-standing issues with the program that predate the pandemic. As the F-35 enters its twentieth year, program officials have delayed the important full-rate production milestone indefinitely because the program still can’t complete the initial operational testing phase.

Weapon programs undergo operational testing to see if they are effective in combat and suitable for use in the hands of the troops. This is different from the developmental testing that engineers and developers conduct to determine whether the weapon meets the engineering specifications of the manufacturer’s contract. The difference between the two processes can roughly be compared to field and laboratory experimentation. In the case of the F-35, the developmental testing done to date has already revealed major shortcomings, but the most serious flaws emerged once the F-35 was in the hands of real operators in the field during operational testing.

The latest annual report from the Pentagon’s Director, Operational Test & Evaluation (DOT&E) details how the failure to deliver a critical simulation facility has made it impossible to complete the initial operational tests required to make the full-rate production decision. The report also questions the program office’s amorphous management plan for future deficiency fixes and upgrades needed for the F-35—an aircraft that remains in every official sense nothing more than a massively expensive prototype.

Highlights of the report include:

  • Engineers can’t complete the Joint Simulation Environment facility. Taxpayers are paying a premium for the F-35 to be capable of defeating any adversary’s defense and anti-aircraft systems. The only way, short of war, to see if the F-35 can perform as promised is to simulate a modern threat environment. The contractor never delivered a functional simulation facility despite having had 14 years to do so, and the facility is still incomplete six years after the Navy was given the project.
  • Program officials continue to struggle against a tide of F-35 design flaws. Nearly every time the engineers solve one problem, a new one is discovered. The F-35 still has 871 unresolved deficiencies, only two fewer than last year. Ten of these are the more serious Category I deficiencies that “may cause death, severe injury, or severe occupational illness; may cause loss or major damage to a weapon system; critically restricts the combat readiness capabilities of the using organization.”
  • The F-35 program made some reliability improvements in 2020, but is still failing to live up to its maintenance and sortie requirements, despite the fact that those expectations were set very low. When aircraft are unable to fly often enough for adequate training, it can result in diminished pilot skills, increased peacetime accidents, and degraded combat effectiveness.
  • For years, one of the biggest weaknesses of the F-35 program has been the deeply flawed maintenance and spare parts computer network called the Autonomic Logistics Information System, known as ALIS. Pentagon leaders finally admitted defeat in 2020 and pulled the plug on ALIS. It will be replaced with the cloud-based Operational Data Integrated Network (ODIN), but the report warns that program officials are repeating many of the same mistakes made with ALIS, which would saddle the troops on the maintenance line with another flawed product.

The F-35 program is approaching a crossroads. The U.S. taxpayers are paying a premium for an aircraft that is supposed to be able to do it all. It is being tested to see if it can live up to the lavish promises made to sell the program. But that testing is revealing significant deficiencies. It’s bad enough that at least 563 F-35s have already been produced under the so-called “Low-Rate Production” loophole that authorizes production before operational testing has been completed. What’s worse is that we will continue to pay for more of the aircraft even as the program office is reducing resources for the tests that would reveal the remaining design flaws so they could be corrected. And the program is nine years behind the original 2001 schedule. All of this has forced the services to resume buying legacy aircraft like the F-15EX and the F/A-18E/F while extending the life of legacy A-10s and F-16s. With the prospect of level Defense Department budgets in the coming years, it is not surprising to hear more and more service officials talk of cutting the F-35 buy well below the planned 2,400.

Incomplete Testing 20 Years In

The long process of testing the F-35 started in 2018 and officially continued throughout 2020, but software programmers have been far busier than the test pilots lately. The F-35 had few actual test flights to complete in 2020 because the majority that had been funded were completed in September 2019. The program had only eight flight-test events remaining to complete the Initial Operational Test & Evaluation process. The program completed three of the events, those involving the Paveway IV bombs and one of the two events involving the AIM-120 air-to-air missiles; a fourth, which was meant to test the AIM-120 missile, could not be completed because designers had yet to finish a necessary software update. The other four events were designed to test the F-35’s electronic attack systems and their ability to suppress or destroy enemy air defenses used by a sophisticated adversary like Russia or China. Specifically, the tests were meant to see how well bombs and missiles launched by the F-35 would work in areas where the enemy disrupted GPS signals. GPS jammers are widely available around the world (small jammers can even be purchased at Walmart); North Korea and Iraq are known to have used them in the past, and Russia and China have integrated them into their defense networks. These tests had been delayed until recently because program officials were slow to contract for and install the necessary range equipment.

The annual report does not provide any information about the results of the completed events, explaining that those details will be included in the combined operational and live-fire test and evaluation reports that will be written after the completion of the testing process.

Even though all of the expected operational tests weren’t completed, program officials had expected to at least conduct a series of tests in a simulator. That didn’t happen either. The programmers could not work out the glitches in the simulator software, so none of the simulated tests began last year.

Although the programmers’ struggles to deliver an effective simulator were compounded by coronavirus-related travel restrictions in 2020, the real trouble with the simulation facility began more than a decade before the virus.

To adequately test the F-35’s ability to operate in the kind of highly contested airspace a reasonably sophisticated adversary would create, the program needs a specialized simulation facility. The current iteration of the facility is called the Joint Simulation Environment (JSE), located at Maryland’s Naval Air Station Patuxent River.

The F-35’s Initial Operational Test & Evaluation master plan requires 64 test scenarios to be “flown” by pilots in the simulator. Those tests can only be done after the simulation software is programed to accurately replicate the real-world performance of all the F-35’s mission systems, and they are required to be completed in order for the test and evaluation process to be finalized. As the DOT&E report puts it: “The JSE is the only venue available, other than actual combat against near-peer adversaries, to adequately evaluate the F-35 due to inherent limitations associated with open-air testing.” Getting the simulation facility right is important for the future of the program as well. The report says the facility “will be an invaluable resource” for both high-end training and tactics development. Yet Navy managers still haven’t finished it, despite the “clear requirements for an F-35 simulation to complete [Initial Operational Test & Evaluation].”

For the simulated tests to effectively predict how well the F-35 will function, the accuracy of the siumlations need to be validated. Validation involves flying real F-35s over test ranges to gather data about how the various mission systems respond when they are triggered by a radar signal or other threat. Software engineers then program those responses into the simulation software to make the entire facility as realistic as possible. DOT&E does not mince words while describing the importance of these data-gathering flights: “Without the open-air test data to validate the JSE, it may not be an accurate representation of installed F-35 performance and thus could provide misleading results to acquisition decision-makers, the warfighter, and Congress.”

In last year’s testing report, DOT&E said it expected the simulation facility to be ready for the official tests in the summer of 2020, but that obviously did not happen. This year’s report notes that COVID-19 travel restrictions affected the progress of the teams working on the project, but also goes on to say that even after people could start traveling again, “continued problem discoveries showed the JSE was still not maturing fast enough to meet a CY20 [calendar year 2020] test-for-score timeline.” The facility is now three years behind the revised 2015 schedule, and DOT&E does not expect it to be ready until “mid-to-late CY21.”

The last-minute scramble to complete the simulation facility is troubling because one version or another has been in the works for 20 years. The original plan for the F-35 program dates back to 2001, and included a requirement for a facility called the Verification Simulator. Lockheed Martin won the contract that year, yet in the 14 years that followed made very little meaningful progress on the simulation facility. In 2015, the F-35 program office decided to pull the plug on Lockheed Martin and hand the project over to the Navy, which essentially started from scratch on the simulation facility. As we noted above, that facility is significantly behind schedule.

Beyond the immediate role the facility plays in the operational testing process, the simulation facility will play an increasingly crucial role in testing future F-35 upgrades as program officials plan to rely on more modeling and simulation. Yet DOT&E warns that the Pentagon continues to shortchange the simulator project. So far, the program has not funded or created plans for future upgrades to the simulation software to include data gathered from open-air test flights.

The testing in the simulation facility is the last hurdle the program must overcome before the Pentagon’s head of acquisition can authorize full-rate production. If DOT&E’s prediction that the facility will not be ready until mid- to late 2021 proves accurate, it is unlikely that a production decision will be made until 2022, by which time the F-35 program will be able to legally purchase its first beer.

The real-world impacts of the F-35’s delays and ever mounting burden on the budget are significant. The delays force the Pentagon to keep older planes in service longer, and paying the ever-increasing costs of the F-35 fleet while still trying to start other new weapon programs the services want leads them to raid the funds set aside to pay for adequate flying hours to keep up the skills of the pilots, and spare parts and maintenance for the legacy aircraft. That has led to an increase in aviation accidents over the past decade, due both to deteriorating maintenance and atrophying pilot skills.

The National Commission on Military Aviation Safety released a report in December 2020 that detailed over 6,000 noncombat accidents between 2013 and 2018 that claimed the lives of 198 servicemembers and destroyed 157 aircraft at a cost of $9.4 billion. The commission’s report specifically cites the F-35 as one of the biggest reasons. The services made major decisions about shutting down legacy aircraft programs based on the early, rosy schedule predictions of the F-35. Spare parts contracts were not renewed, depot maintenance was cancelled, supply and maintenance facilities were shut down, personnel transferred, and parts became scarce for the legacy fleets. Readiness rates plummeted and lives were destroyed because of unending F-35 schedule slippages and burgeoning sustainment costs.

Struggling Against the Tide of Design Flaws

DOT&E reports that as of October 2, 2020, the F-35 program had 871 unresolved design flaws. Ten were classified as Category I, the most serious type of flaw. The total number of Category I problems shrank by only three since last year’s report.

The 2020 report did not provide any details about what the outstanding problems were, but previous reports showed that the gun in the Air Force’s F-35A variant was inaccurate and damaged the structure of the aircraft when it was fired. That problem has yet to be fixed and, as Air Force leaders have hinted, may not be a priority. Engineers have worked to correct many of the F-35’s problems, but they are struggling against the tide of newly discovered flaws. This is particularly true of the aircraft’s software, and all variants of the aircraft have suffered from software instability. As has been the case in the past, the latest report again found that when engineers fix one software problem they “often introduced stability problems and/or adversely affected other functionality.”

Another significant shortcoming of the F-35 program is its vulnerability to hacking. For many years, Pentagon leaders have known the F-35 is an inviting target for enemy cyber-warriors. The jet is still often—and unironically— described as a “flying computer,” but with the alleged capability benefits that come from its highly networked mission and support systems also come many potential vectors in the aircraft’s software and ground-based information systems that a malign actor can exploit to disrupt or disable the entire F-35 fleet.

For the last five years, DOT&E has reported the same basic theme regarding F-35 cybersecurity, repeatedly concluding that while some progress has been made, weaknesses remain. Once again, in 2020, the program “continued to demonstrate that some vulnerabilities identified during earlier testing periods have not yet been remedied.” DOT&E reported almost the same thing in the 2016 report. The problem will likely only get worse from this point forward as the frequent software updates that are part of the upgrade process mean the cyber testing teams will struggle to keep up. As DOT&E reports, “An increased frequency of new software deployments may stress the capacity of cybersecurity test teams to thoroughly evaluate each update.”

Until engineers can begin to correct design flaws faster than new ones are discovered, F-35 pilots in all services will continue to fly deeply compromised aircraft.

Most of the cyber testing done so far has been inadequate to reveal all of the potential weaknesses in the F-35 program. Until 2020, cyber testing for the F-35 had been done in laboratories like the Fort Worth, Texas-based Mission Systems Integration Lab, where individual F-35 mission system components are set up to mimic a real aircraft. Laboratory testing like this does not reveal all potential vulnerabilities because in a lab it is impossible to recreate all of the potential attack surfaces on the aircraft or in the ground-based support networks. DOT&E has previously called for the cybersecurity tests to be conducted on an actual aircraft so they can more effectively test the entire network. Program officials did arrange in 2020 for an actual F-35 to be set up for cyber testing at Pax River in Maryland, but the results of any testing done to this point have yet to be reported.

Until engineers can begin to correct design flaws faster than new ones are discovered, F-35 pilots in all services will continue to fly deeply compromised aircraft, a circumstance that will impact their training and potentially limit their ability to perform in combat if called to do so.

Fewer Breakdowns but Slower Fixes

One of the F-35’s most persistent problem areas is the reliability of the fleet. The F-35 is a notoriously maintenance-intensive aircraft. The difficulties involved in keeping the aircraft out of the maintenance hangar and ready for combat mean that the F-35 fleet cannot perform missions as often as it should. No matter what supposedly game-changing combat capabilities the aircraft has, none of it matters if the F-35 can’t perform when it is truly needed.

The key combat-relevant readiness metrics, in declining order of importance, are sortie rate, fully mission capable rate, mission capable rate, and availability rate. Fully mission capable rate is the percent of time the airplanes the units have in their possession are ready to execute all of their designated combat missions; mission capable rate is the percent of time that the planes the units have in their possession are ready to accomplish at least any one of its combat missions. Availability rate is the percent of time that all aircraft—including all the non-assigned planes undergoing major repair, modifications, or overhauls—are ready to fly at least one assigned mission. Thus, availability rate is always lower than the mission capable rate.

The most-often cited readiness rate for the program is the mission capable rate. The 2020 DOT&E report avoids mentioning specific figures, but says that while there were modest improvements, the F-35 fleet as a whole failed to meet the 70% mission capable goal. Previous DOT&E reports provided charts showing specific availability rate data. Future reports should do so as well so Congress has a complete picture on the program’s performance.

The better measure of the fleet’s true readiness for combat is the fully mission capable rate. Taxpayers are paying a premium for the F-35 to be able to perform multiple roles, and the fully mission capable rate measures whether they’re getting what they’ve paid for. And it is in those fully mission capable rates that the true shortcomings of the F-35 as a program come into sharp relief.

This year’s DOT&E report is short on specific figures, but it is clear the F-35 fleet is not meeting the modest fully mission capable expectations set for it. Program officials set mission capable and fully mission capable goals for the whole fleet of 70% and 40%, respectively, which should have been reached by September 2020. The Air Force’s F-35A improved a bit in this regard during 2020, but the Marine Corps F-35B fleet saw its fully mission capable rate drop. The Navy’s F-35C fleet’s fully mission capable rate remained stagnant. On the surface, that might seem like a good thing, but the Navy’s F-35 fleet had nowhere to go but up. DOT&E reports that the F-35C’s fully mission capable rate “showed a stagnant trend at a very low rate between 2019 and 2020.”

For a refreshing change in 2020, there were actually some readiness improvements. The program partially solved the supply issues that prevented F-35 squadrons from receiving needed replacement parts, which accounts for most of the improvement in the overall fleet availability rates. In years past, nearly a third of the F-35 fleet was unable to fly at any given time because maintenance crews could not get the parts they needed for critical repairs. DOT&E reports that the investments made to improve the flow of replacement parts through the supply chain had improved the supply issue to the point that by September 2020, the program had finally met the goal of no more than 10% of the fleet grounded for a lack of spare parts.

Even given the years of experience maintenance crews have with the aircraft, DOT&E reports it took them longer to make repairs on the F-35 than it should have—sometimes more than twice as long.

The long-harrowed F-35 maintainers also appeared to have received a bit of a respite in 2020. Individual aircraft did not suffer as many mechanical breakdowns as in previous years, which is a significant improvement. DOT&E reported that some of the metrics rose to “a historically unprecedented degree for the program.” In fact, the program saw improvement in all four of the maintenance reliability reporting categories.

It’s definitely a good thing that the F-35 doesn’t break down as often, because when it does, maintenance crews have a difficult time making repairs. Even given the years of experience maintenance crews have with the aircraft, DOT&E reports it took them longer to make repairs on the F-35 than it should have—sometimes more than twice as long. A key measurement for maintenance actions is the mean time to repair. Pentagon officials had set goals for the average repair times as part of the original F-35 contract. Rather than implementing upgrades to shorten F-35 repairs and thereby meet the original goals, program officials simply moved the goal posts and doubled the threshold. For example, the original contract specified that Lockheed Martin needed to produce an aircraft with a 2.5-hour repair time threshold for the F-35A. Lockheed Martin wasn’t able to deliver on that contract specification, so Pentagon officials changed the contract to reflect the 5 hours it now takes to complete the necessary repairs. DOT&E warns that the longer repair times will make it harder for the fleet to generate the number of sorties it should to meet the needs of the services.

It remains to be seen what, if anything, can be done to turn the F-35 into an aircraft the troops can count on when they need it.

The longer maintenance times contribute to the excessively high F-35 ownership costs, an issue that has caused Pentagon leaders to question the program’s viability. It costs approximately $44,000 per hour to fly the F-35. Extrapolated out over the expected 8,000-hour lifespan of each F-35, the services will spend $352 million to operate a single jet. That means the Air Force alone will spend more than $620 billion, or approximately 36% of the total program cost, to operate its planned fleet of 1,763 F-35s over the lifespan of the program. For comparison’s sake, the A-10s and F-16s the F-35 is supposed to replace each cost less than half that, at approximately $20,000 per hour to operate.

The services expended a great deal of energy to improve F-35 readiness rates in recent years. For example, service leaders added extra maintenance shifts for Air National Guard units to complete repairs faster. But it is clear that, with the exception of increasing the supply of spare parts, the basic metrics used to measure the overall reliability of the F-35 fleet hardly budged over the past several years. It remains to be seen what, if anything, can be done to turn the F-35 into an aircraft the troops can count on when they need it.

Maintenance Network Troubles Endure

Following years of disappointing news about the F-35’s troubled cloud-based maintenance and logistics network, the Autonomic Logistics Information System (ALIS), the Pentagon finally threw in the towel in 2020 and will spend $550 million over the next 5 years to build an entirely new one. The Operational Data Integrated Network (ODIN) is slated to replace ALIS by the end of 2022, but DOT&E warns that the Pentagon’s development and deployment plans are unrealistic. In fact, according to DOT&E, “the ODIN software and hardware deployment schedules are even more aggressive and less-defined than the accelerated quarterly ALIS software releases,” and the report went so far as to call the schedule “high risk.”

ALIS is the network owned and operated by Lockheed Martin that integrates combat mission planning, threat analysis, maintenance diagnosis, and supply chain management. It was meant to make it easier for maintenance crews to do their jobs by gathering data that could predict breakdowns and automatically order replacement parts and guide crews through repairs. What ALIS actually did was increase the workload of the maintainers through an excess of false positive fault reports and erroneous parts deliveries, forcing the maintainers to perform time-consuming workarounds to order and track parts through the supply chain. According to the Government Accountability Office, “one Air Force unit estimated that it spent the equivalent of more than 45,000 hours per year” working around ALIS.

While almost anything might be an improvement over the ALIS disaster, ODIN, which is a joint project built by government and the defense industry, is already stumbling right out of the starting block. As program officials race to field ODIN, they are taking shortcuts during the development and testing process. “The lack of ODIN developmental testing may leave system and design flaws undiscovered until after release to the field, requiring significant rework and patching,” the DOT&E report warns.

As far as that goes, the ODIN managers seem to be repeating the same mistakes the ALIS managers made. ALIS went through four separate versions in 2020 alone, including one urgent fix over the summer meant to correct a problem in an earlier patched version that generated 10 times the normal number of maintenance alarms.

DOT&E reports that the poor development plan and a lack of resources for the project will make it difficult for the program to deliver an effective replacement for ALIS this year, a concern that has been echoed on Capitol Hill. Unmentioned in the report is the real possibility that ODIN, like ALIS, will have significant cyber vulnerabilities simply because it resides in the cloud.

Based on the history of the F-35 program, it is difficult to see whether a workable and secure maintenance and logistics network will ever be delivered. This threatens the success of the entire program because the F-35 can’t operate without an effective ground-based information network.

Failed “Modernization” Scheme

When it became apparent to the F-35 program’s leaders that they would not be able to deliver all of the promised capabilities or fix all of the design flaws within the $395.7 billion budget or time frame of the revised 2011 contract, they decided in 2018 to shift much of the remaining work into what they called the modernization phase of the program, thus avoiding the need to admit to major development overruns and further schedule slips. The then-program executive officer, Vice Admiral Mat Winter, termed this upgrade process Continuous Capability Development and Delivery. This process, DOT&E writes, “is not working” and is “causing significant delays to planned schedules and results in poor software quality containing deficiencies.”

Under the Continuous Capability Development and Delivery process, at least in theory, engineers would continually update the F-35 in six month-increments, installing upgrades, adding new weapons and sensors, and uploading improved software without firm schedules or milestones. Many of the so-called upgrades will be fixes for the myriad design flaws engineers and test pilots have discovered during testing so far. The six-month goal proved totally unworkable, however. According to DOT&E, it took between May 2019 and July 2020—13 months—to complete the first Continuous Capability Development and Delivery increment. Engineers planned four software builds for this first increment but ultimately needed 12 to complete a final version that could be installed on the F-35. As is often the case with complex software, when designers added a new patch to the F-35 software to correct problems already discovered, new problems emerged requiring yet more patching. The second increment also originally planned for four software builds, but ended up requiring seven in a development process that at the time of the report’s publication was projected to last a year, from November 2019 to November 2020.

The upgrade plan set out by the Pentagon would have seen the process completed by 2024 at a cost of $6.6 billion. If the subsequent increments follow a similar doubling of the time-to-completion as the first two, the project won’t be finished until 2030, likely with a corresponding increase in costs.


There can be little doubt that, after 20 years, the F-35 is a complete boondoggle. DOT&E warns that many of the F-35s that were delivered early on in the cycle are not combat-ready. It remains to be seen if these aircraft, which happen to be the most expensive ones, will ever serve a purpose beyond being demonstration trainers or spare parts repositories. It is natural for the Pentagon hierarchy to run interference for failures rather than admit its mistakes, but that can only go on for so long before the truth becomes too obvious and defectors begin to emerge. Then-Acting Secretary of Defense Christopher Miller, as a parting shot before he happily left the Pentagon in January, called the F-35 “a piece of…” and then went on to say that the United States had created a monster.

Will Roper, then-head of Air Force acquisition, recently cast doubt on the future of the F-35 program when he suggested that it could be replaced at least in part by the Next-Generation Air Dominance program. “I think [the F-35] is a long way from being an affordable fighter we can buy in bulk” which seemed to imply that the Air Force wouldn’t be able to afford the fleet it currently plans. Roper says that the new program will be designed with sustainability in mind, an unsubtle jab at a key shortcoming of the F-35 program.

Pentagon leaders owe it to the American taxpayers to study what went so drastically wrong with this program and to not repeat their mistakes.

Public comments like this from top Pentagon officials suggest there are plenty of similar private conversations at all levels. It could signal that the F-35 program may about to face the same fate as several other once-marquee 21st century weapon programs like the Zumwalt-class destroyer, the F-22, and the Littoral Combat Ship. In other words, just like those disastrously failed programs, the F-35 may be dramatically reduced in scope due to a combination of technological failures and skyrocketing costs. That would be a fitting, if costly, end for a program that has been troubled from the very beginning. If that does happen, Pentagon leaders owe it to the American taxpayers to study what went so drastically wrong with this program and to not repeat their mistakes. It remains to be seen if the key players in the Pentagon, the defense industry, and Congress can repress their tendencies to design and purchase overly complex weapons that are based on fanciful concepts unrelated to actual combat needs and that are executed with unproven technologies. Unfortunately, both the Air Force’s and Navy’s Next-Generation Air Dominance concept design efforts are already showing signs of heading down the same business-as-usual paths to the same disastrous outcome.

In the meantime, the troops that by now were supposed to be supported with F-35 close support and air cover continue to rely on life-extended A-10s, F-16s, and F-18s. Fortunately, these airplanes are proving every day that they can serve the troops well, certainly much better than combat-unready F-35s. Clearly, one path out of this debacle is to cut our losses on the F-35 in order to work full-speed on replacing the legacy planes with far more combat-effective close-support and air-to-air fighters that we could reliably deploy in adequate numbers without breaking the bank for our taxpayers. Don’t we owe it to our troops to do exactly that?