There’s lots of nervous talk about the trajectory of the global economy, perhaps with some justification given rising interest rates, banking stress, lingering inflation, ongoing geopolitical tensions, weak freight markets, and cooling labor markets. There’s a more optimistic scenario, however, and airlines are feeling it. Travel demand, for one, remains almost universally strong, with even China now finally joining the party. The average price of U.S. Gulf Coast jet fuel in April was down 39 percent year-over-year. Oil prices have dropped to a level consistent with earlier periods of healthy economic growth — and yes, there’s a correlation. A strong…