I was basing my comment on the photo, which shows the lineup for the first album. Only three remain from the photo: Jorma, Jack and Marty.
Of the classic lineup, four remain, the above three and Grace. That is probably what Jorma meant.
If you go by the first band that never recorded, there are still four. I believe Bob Harvey and Jerry Peloquin are still around, definitely the latter since I spoke to him on Facebook.
I can't imagine the Airplane without Jack. No recordings of the original band have ever surfaced, right?
Bertrand.