>> caller: well airlines change their schedules all the time essentially trying to adjust to passenger demand. so they'll revise their schedules, typically. at least twice a year and often for individual routes in between those times. when you do revise the schedule you need to apply for various permissions. and compliance with the air traffic, the services rules as to how many flights you're authorized to operate and which days of the week and so on and so forth. and then there are other things you have to apply for the slots for takeoff and landing at particular airplanes and a route for a particular day, you have to fly for permission to fly the route and get air traffic control clearance. so there is a lot of paperwork behind regular operations on a regular daily basis. so what was or wasn't done on this case they'll have to go through the paper trail and