Non-revenue passengers, more popularly referred to as chance passengers, are travelers with flight privileges to fly either for free or at significantly discounted rates. It is worth noting though that some chance passengers are not necessarily non-revenue passengers, like those full-paying travelers requesting for sudden changes in their flight itineraries and trying their luck that their targeted flights are not full. These non-revenue passengers are airline employees or some of their family members and friends. However, free or discounted fares may also