In each of the three recessions shown, airline unit margins went from positive to negative, and the pandemic collapse ran several times deeper than either earlier downturn.
What this shows: The chart covers 2001 to 2020. It plots Pre-recession margin (¢ per available seat-mile) and Trough margin (¢ per available seat-mile) on a vertical axis of Unit margin (¢ per available seat-mile). Latest values: Pre-recession margin (¢ per available seat-mile) 1.67; Trough margin (¢ per available seat-mile) -7.19. Data run through 2020.