not tracking UAL946

Today the 19th, Flight aware is not tracking UAL946 from LAX to IAD. Why when it has been airborne for at least 30 minutes?

Here ya go… … /KLAX/KIAD

Same situation for UAL914 SFO-IAD. How do I know that I have to put a T in after flight number?

I just looked under the departures and used the “find” feature to find the two flights you mentioned. Here is the second one, only has an “L” and not a “T”. … /KSFO/KIAD