I have Just filed my papers, l am not yet a citizen. Do I need a passport to fly inside the USA?

Please confirm your status, you are an applicant for permanent residence? If so, you should have filed for an EAD, that is evidence of your lawful status in the US. If you are still a NIV, then you should travel domestically with your passport, with visa and I-94.

I trust this is responsive to your inquiry.