The countdown to Europe's next aviation crisis is being measured in days of supply, not weeks of summer. According to a Goldman Sachs research analysis, Europe's commercial jet fuel stocks are on course to dip below the International Energy Agency's critical 23-day shortage threshold sometime in June — just as summer travel demand hits its annual peak. In August, demand runs roughly 40% higher than in March.
Before US and Israeli strikes on Iran in late February, the Middle East supplied around 75% of Europe's jet fuel imports. Since the Strait of Hormuz effectively closed, output from those refineries has fallen to near zero. European refineries have responded by increasing jet fuel production — in some cases at the expense of other fuel streams — but they cannot close the gap alone.
IEA Executive Director Fatih Birol put it plainly in April: Europe had "maybe six weeks or so of jet fuel left" at the current pace of replacement. That six-week window has now elapsed. The question is whether the reserves accumulated since then are sufficient to bridge the shortfall through the most intensive flying months of the year.
The response from carriers has been rapid and significant. Across Europe, airlines pulled 13,000 flights and more than two million seats from their May schedules. KLM made the first high-profile move, cutting 160 routes from Amsterdam Schiphol, citing "rising kerosene costs" that made those flights economically unviable. Lufthansa went further: grounding 27 short-haul aircraft and retiring four long-haul A340-600s ahead of schedule. SAS cut roughly 1,000 flights in April. Turkish Airlines suspended 18 international routes across May and June.
On Sunday, KLM escalated its warnings. The Dutch carrier said it may extend cuts beyond the summer season if fuel costs and Dutch aviation taxes do not ease — a signal that the disruption could outlast the immediate crisis phase. Some carriers have turned to surcharges rather than seat reductions. Spanish low-cost airline Volotea began adding a fuel levy to already-purchased tickets — a highly unusual step that shifts the burden directly onto booked passengers.
The critical risk in the coming weeks is the convergence of falling stocks and rising demand. The IEA's 23-day threshold is not a soft advisory — it is the level at which emergency stock releases and demand-rationing protocols typically activate. Goldman Sachs estimates that threshold will be breached in June if current import-replacement rates hold. A disruption that persists through July and August could force more radical interventions, including coordinated emergency releases from EU strategic reserves.
Europe's refineries are working to compensate by shifting to higher jet fuel yields, but refinery output adjustments take weeks — not the days now available before summer bookings peak. The IEA's own Oil Market Report projects that if Europe replaces only half of lost Middle East volumes, stocks will breach the critical threshold by June regardless of domestic production increases.
European passengers should expect further route cuts, higher fares, and — for some — fuel surcharges on tickets already bought. The crisis that began as a geopolitical standoff over the Strait of Hormuz has arrived at the departure gate. Airlines are making financially driven decisions about which routes to sustain, and with stocks approaching the critical threshold in June, those decisions will increasingly become involuntary. The energy shock is no longer just a macro-economic headline — it is now directly determining which Europeans can fly this summer, and at what cost.
