Cost classifications 1) Listed below are costs of providing an airline service. Classify each cost as either variable or fixed AND either direct or indirect. Consider the cost object to be a flight. Flight attendants and pilots are paid based on hours of flight time. Variable or Fixed Direct or Indirect Cost Advertising Beverages served on planes Regional vice president salary Depreciation (straight-line) on ground equipment Fuel used in planes Flight attendant wages Pilot wages Aircraft maintenance manager salary