in addition,airlines lose a lot of

in addition,airlines lose a lot of money when expensive equipment, such as an aircraft, is idle.
Flight and crew scheduling, however, is a complex process. For example, Air New Zealand is a group of five airlines with a combined fleet of 105 aircraft, with another 21 more on order. The average utilization is 8.28 hours per day. It has undergone an $800 million upgrade to its long-haul service, refitting its boeing 747 fleet and adding eight new boeing 777-200 aircraft for flights to North America. It directly server 50 port-26 domestic and 24 international within 15 countries. It carries 13.4 million passengers annually, and its network incorporates flight times ranging from 15 minuter to 13 hours