The airline sector is trading significantly lower following a stark warning from American Airlines' CEO about the impact of surging jet fuel prices on profitability. This adds to the negative sentiment created by major operational disruptions, as the FAA has been forced to halt flights at 13 major U.S. airports due to more than 4,000 flight cancellations over two days. These combined pressures of rising costs and significant operational interruptions are the primary drivers for the negative performance of airline stocks.