US Air Force's Aerial Refueling Fleet Has Missed Readiness Goals Every Year Since 2019
A new report from the Government Accountability Office (GAO) has delivered a stark warning about one of the most critical — yet often overlooked — components of American air power: the aerial refueling tanker fleet. According to the watchdog's findings, the US Air Force's tanker aircraft failed to meet their own readiness and availability standards every single year from fiscal year 2019 through fiscal year 2025. That's six consecutive years of falling short, and experts say the implications for national security could be serious.
What the GAO Report Found
The GAO report zeroed in on two key aircraft: the aging KC-135 Stratotanker, a workhorse that has served the Air Force since the 1950s, and the newer KC-46A Pegasus, which was meant to modernize the fleet for the decades ahead. Neither aircraft met the Air Force's own benchmarks for availability and mission-capable rates throughout the six-year period examined.
Critically, the GAO found that while the Air Force had already identified what it called "sustainment risks" for the tanker fleet, it had not taken meaningful steps to address them. The service "has not comprehensively assessed these risks or developed a plan to mitigate them," the report stated. In other words, leadership was aware of the problems but failed to act with the urgency the situation demanded.
The Root Causes: Parts, People, and Infrastructure
The GAO's report pointed to three major categories of problems dragging down tanker readiness, each compounding the others in ways that make the overall situation difficult to reverse quickly.
Shortages of Critical Repair Parts
One of the primary drivers of poor readiness is a persistent shortage of the spare parts needed to keep aging aircraft flying. The KC-135 in particular has been in service for over six decades, and sourcing components for a platform that old is an ongoing logistical challenge. When aircraft sit grounded waiting for parts that aren't available, mission-capable rates inevitably suffer. Supply chain disruptions and the industrial base's limited capacity to produce certain legacy components have made this problem worse in recent years.
Maintenance Staffing Gaps
Even when parts are available, you need skilled technicians to install them and keep complex aircraft airworthy. The GAO report identified a significant lack of qualified maintenance personnel as a major factor in the readiness shortfall. The Air Force, like many branches of the military, has faced recruitment and retention challenges across technical career fields. Training pipelines for aircraft maintainers take time, meaning staffing gaps can persist for years even after efforts to fix them begin.
Infrastructure Limitations
The third pillar of the problem is infrastructure. Aging hangars, maintenance facilities, and support equipment that haven't kept pace with operational demands place an additional burden on the fleet. Without adequate facilities to conduct inspections, depot-level maintenance, and modifications, aircraft availability suffers. This kind of infrastructure investment requires long-term planning and sustained funding — precisely what the GAO suggests has been lacking.
Why Tanker Readiness Matters So Much
To understand why these findings are so alarming, it's important to appreciate just how central aerial refueling is to virtually every major US military air operation. Tankers are often described as "force multipliers" — aircraft that dramatically extend the range, endurance, and operational flexibility of fighter jets, bombers, surveillance platforms, and transport aircraft alike. Without adequate tanker support, the Air Force's ability to project power globally is significantly constrained.
Military demand for aerial refueling has surged during recent major combat operations. Modern air campaigns rely on continuous tanker availability to sustain around-the-clock sorties, respond to rapidly evolving threats, and operate in contested environments far from friendly bases. A fleet that consistently falls short of its readiness goals is one that may not be able to deliver when it matters most.
The strategic stakes are particularly high given the current security environment. As the United States continues to prepare for potential high-end conflicts against near-peer adversaries — scenarios that would place enormous demands on every segment of the Air Force — gaps in tanker readiness represent a genuine vulnerability.
A Fleet in Transition — and Under Pressure
Part of the challenge stems from the Air Force being caught in an awkward transition between generations of aircraft. The KC-135 fleet is extraordinarily old; some aircraft are older than the pilots and maintainers who operate them. The KC-46A Pegasus was designed to begin replacing it, but the newer aircraft has faced its own well-documented technical problems since entering service, including issues with its Remote Vision System used to guide refueling operations. Neither aircraft has been able to fully pick up the slack for the other, leaving the overall tanker enterprise stretched thin.
Efforts to develop a next-generation tanker — the KC-Z program — are still in early stages, meaning the Air Force will depend heavily on the KC-46A for the foreseeable future. That makes addressing the readiness shortfalls in that aircraft's fleet all the more urgent.
What Needs to Change
The GAO's core recommendation is straightforward even if the execution is complex: the Air Force must conduct a comprehensive assessment of sustainment risks across its tanker fleet and develop concrete mitigation plans. Piecemeal fixes and informal workarounds are no longer sufficient given the scale and duration of the readiness problem.
Addressing the parts shortage will require investment in the defense industrial base, smarter supply chain management, and potentially accelerated procurement timelines. Closing maintenance staffing gaps will demand improvements to recruitment incentives, retention bonuses, and training pipeline throughput. Fixing infrastructure deficiencies means securing long-term funding commitments that survive budget cycles and leadership changes.
Congress, which has oversight responsibility over the Department of Defense, is also likely to scrutinize these findings closely. Lawmakers on the armed services and appropriations committees have repeatedly pressed the Air Force on tanker readiness in recent years, and this latest watchdog report will give them fresh ammunition to demand accountability and action.
The Bottom Line
Six years of missed readiness targets is not a blip or a temporary setback — it is a systemic failure that demands systemic solutions. The GAO's report on the US Air Force's aerial refueling tanker fleet is a clear signal that one of the military's most critical enabling capabilities is under strain. Fixing it will require honest assessment, sustained investment, and the kind of long-term planning that has apparently been absent from the Air Force's approach to tanker sustainment so far. The cost of inaction, measured in reduced operational capability at a time of rising global threats, is simply too high to ignore.