Yield management alerts airlines to abnormal boking patterns, estimated number of passengers,overbookings, number of seats that can be overbooked, and how many customers will cancel. Most airline personnel belong to a union. Most union negociations last a year before a settlement is reached. Fuel costs is the second largest operating cost category representing approximately 10 percent of costs. Some airlines hedge fuel prices by buying and selling futures on the commodity market.
Weather can also affect airline costs and operations.
Wind speed and air temperatures influence how much fuel an aircarft needs. Weather is the second largest cause of airline fatalities. The airline industry must obtain detailed weather forecasts that includes cloud height, horizontal visability, wind speed, and direction. Airline equipment represents 9 percent of total costs. Airlines either buy or lease their fleet of aircraft.