What did you do when you discovered the iPad was lost, like Brandon said, time is of essence, with security alertness everywhere, it could be found and detained for destruction, also check other places you visited, it may be lying somewhere else. Let's know how far you have gone.
If you haven't already, I'd try "Find My iPhone". Anything associated with your Apple ID should be trackable as long as it's connected to the internet. So long as there is an Apple ID on the device, there is no way anyone can really sell it or use it without an amount of effort and expertise that would ultimately defeat the purpose. Hope this helps!
You can claim to airline but need to prove it u have it
Lost and found in baggage claim area
Also, there is a lost & found counter at the Airport . Report and file a claim with the flight number etc. Good luck.
Your only shot is to contact the airline if you already left the gate area honestly. Try going to the ticket counter, speed is of the essence as you want to try and catch them before the crew changes or new passengers get on board.
Thanks! Your answer is awaiting moderation.