Altitude Adjustment: Smart Strategies for How Airlines Can Reduce Fuel Costs: A Complete Guide In the fast-paced realm of commercial aviation, profit margins can often feel like they're measured in mere pennies per mile. For airlines that operate on a global scale, the biggest variable expense isn't labor, maintenance, or landing fees—it's fuel. When oil prices take a turn, they can quickly transform a profitable quarter into a hefty loss. So, the question of "how can airline