The jet-fuel surge is making global flight connections disappear

Airline passengers should brace for more aggravation in the next few months as carriers around the world deepen cancellations and ground planes to cope with stratospheric increases in jet-fuel prices.

Dutch flag carrier KLM is the latest company to cut its schedule, saying Thursday it will scrap 80 return flights at Amsterdam’s Schiphol Airport in the coming month. That puts it in the same league as United Airlines Holdings Inc., Deutsche Lufthansa AG and Cathay Pacific Airways Ltd. which have all pruned itineraries to contain the damage.

Global capacity for May has been reduced by about 3 percentage points, with all but one of the 20 largest airlines slashing flights, according to data compiled by analytics firm Cirium Ltd. It’s revising an initial prediction of 4%-6% growth for the year and says a decline of as much as 3% is possible under certain conditions.

“It appears extremely likely that more reductions are ahead,” wrote Richard Evans, a senior consultant at Cirium, in a report released Thursday.

The disruptions roiling the aviation industry after the war in Iran started were initially limited to Middle Eastern airlines, their airports and airspace. They’ve since become contagious and threaten to upend the lucrative summer travel season globally. And with the U...