The sum of the products obtained by multiplying the number of revenue flight stages flown, by the corresponding stage distance.

Breakeven load factor: The weight load factor at which point operating revenues equal operating expenses. It is obtained by multiplying the weight load factor by the ratio of the operating expenses to the operating revenues

Leased aircraft: An aircraft used under a contractual leasing arrangement to increase an air carrier fleet capacity

Maximum certificated take-off mass (MCTOM): The maximum permissible take-off mass of the aircraft according to the certificate of airworthiness, the flight manual, or other official documents.

Operating costs: Air carrier operating costs are generally subdivided into: Direct operating costs (DOC), i.e those costs incurred in operating the aircraft which cover the following main accounts: flight operations, flight equipment maintenance and overhaul, flight equipment depreciation, and user charges. Indirect operating costs (IOC) cover the remaining operating cost items, i.e, station expenses, passenger services, ticketing, sales and promotion and, general and administrative expenses.