We are using the XML2 API and received some feedback from one of our users that AA #2270 from KJFK to KORD did not appear on 1/2/18. After looking into it further, it appears that Delta #4095 is also missing on that route/date. This was confirmed via API call to the XML2 FlightSchedules API as well as by using the FlightAware public page here:
https://flightaware.com/live/findflight?origin=KJFK&destination=KORD
Both of these flights exist and are available on the AA and DL websites as well as Google Flights.
Please advise why these flights are not appearing in the Schedule API. Thanks!