How do I figure out when a designator has been reassigned?

1. Run a Schedule Weekly Dynamic table report in time series mode. 
2. Set the desired airline as the Marketing Airline code
3. Include restricted flights
4. Set the Period to Range of Months
5. Set your date range to inspect
6. Set Flights as the Data metric
7. Set Origin Country as the Columns field
8. Add the Operating Airline as a Column field for a more robust result set
9. Set Month as the row field

In the example above, we see that designator ‘CO’, Continental Airlines, was active until Feb 2012, then ceased operations. Flights began again for designator ‘CO’ in Jul 2016.  This time they belong to Cobalt Air.

You can get this additional information by clicking the ‘CO’ link in the report parameters info located below the results. You will be redirected to the Airline Reference report.