Unresponsive iPad Air's screen

Take a look at a few of the suggestions on here: https://support.apple.com/en-gb/HT201406

If they do not resolve the issue, as the guide states, you may have to contact apple support.

You could also try a forced restart and see if the screen responds after the iPad boots up.

• iPad models that don't have a Home button: Press and quickly release the Volume Up button. Press and quickly release the Volume Down button. Then press and hold the Power button until the device restarts.
• iPad with Home button, iPhone 6s or earlier, and iPod touch (6th generation) or earlier: Press and hold both the Home and the Top (or Side) buttons until you see the Apple logo.