I knew this at one point, and in fact it is embarassing that I have forgotten it. I am wondering what filtartion of the total space of a fibration we use to get the Serre SS. I feel very comfortable with the Serre SS, I am just essentially looking for a one line answer. I checked have Hatcher, Mosher and Tangora and Stricklands note on Spectral Sequences.
I think it has something to do with looking at cells where the bundle is trivializable..