Individual flight trajectories from start to finish

With flightradar24, I can download a csv file for any flight that occurred in the past without having to know when the aircraft took off or landed. I can look for flights that occurred yesterday and download the respective files. Maybe this feature is already available, but I'm having difficulty finding the right way to duplicate this feature. I'm currently getting states and using the icao24 code to then get the tracks, but I'm having issues filtering and differentiating between completed and ongoing flights.

Thanks for your quick reply and the information you provided. As a PhD researcher, I've developed a post-processing algorythm to augment, correct, and determine flight phases for any (and therefore all) flights from offblock to onblock. Missing data concerning certain phases is augmented in accordance with the ICAO's "sophisticated" method. Using the phases and the applicable fuel consumption tables (provided by Airbus, Boeing, and Lufthansa), I generate how much fuel is consumed per second for any flight. With this info, I follow the standard methods to determine emissions. Getting my hands on individual flight trajectories would be helpful, but I can create a workaround. Thanks again for the information and the support, and have a great weekend. VG, Phillip