High jet fuel prices could force European and US airlines to ground more aircraft than usual this winter. Aviation analyst John Strickland says weaker frequencies and marginal routes are drifting below break-even, and operators may cut capacity rather than chase demand with lower fares that still miss the fuel bill. The seasonal pullback comes after a summer peak that has so far masked supply pressure through hedging and alternative sourcing. IATA is projecting fuel spend to rise almost 40% to 350 billion dollars in 2026, equal to 31.4% of operating expense, sharpening the economics of winter schedule reductions and lifting cancellation risk on thin services.