In the center of the blue header is a box with the text "Airline flight, aircraft tail #, airport, or city" with a "Track" button to its left. You can type callsigns, tail numbers, airport codes, airport names, etc. into that box, and click "Track."
You're not the only one who has missed it - we're working on making it more noticeable.
I'm sorry to hear you're frustrated. Do you have examples of searches that you can't perform in the current configuration that you could under the old?
Thanks for the feedback. Can I ask if you are on Windows or on a Mac? They render fonts differently, and that is possibly contributing to readability issues.
You can enter a flight number (DAL1188, or "Delta 1188") into the search box in the header, and then press enter or click "Track."
If you prefer the old search boxes, they are available from the dropdown to the left of the box.
PiAware is a way you can build and run your own ADS-B ground station, and receive real-time data directly from airplanes on your computer. It feeds data to FlightAware to make our flight tracking more complete. https://flightaware.com/adsb/piaware/build