The airline is in the middle of a plan to reduce costs by culling unprofitable routes and drumming up revenue with higher-priced seats.

JetBlue is executing a cost-cut strategy of cutting unprofitable routes, deferring aircraft deliveries and pricing premium seats. It was also reported by CNBC that the airline has already offered senior pilots voluntary early retirement packages as part of the restructuring.

Unit costs in 2025 will rise as much as 7% excluding fuel, the airline said Tuesday in a statement, outpacing analysts’ estimates on higher spending for compensation and aircraft maintenance. JetBlue shares fell as much as 18% as markets opened in New York, their biggest slump since Aug. 12.

JetBlue’s fourth-quarter results beat expectations, but the outlook for a key revenue metric was below forecasts.