Cost index theory

Cost index theory helps airlines decide the most economical cruising speed and altitude for a flight by comparing the costs of fuel consumption and flight time. It balances fuel costs against the expense of longer flight durations, aiming to minimize overall expenses. A higher cost index means prioritizing speed to save time, often increasing fuel burn, while a lower cost index favors conserving fuel by flying slower. Airlines use this theory to optimize operations, ensuring cost efficiency while meeting schedule needs.