A high cost index typically indicates what about flight speed?

A high cost index suggests that the operating costs per mile increase with flight delays or slower speeds. When the cost index is high, it typically indicates that the airline prefers to prioritize speed over fuel efficiency since flying at higher speeds may reduce the overall duration of the flight and thus the time-related costs associated with delays.

On the contrary, a lower cost index might encourage slower flight speeds to optimize fuel savings. Therefore, flying faster when the cost index is high aligns with the operational strategy to minimize overall costs by completing flights more quickly. It reflects a balancing act between fuel efficiency and time, where a higher expenditure on fuel is justified by the benefits of quicker turnarounds and less potential for incurring costs related to delays.