Originally Posted by
DWFI
321 does not board from L2 except under rare circumstances (and never on AA). LH tends to do it once in a while.
Correct. Specifically, AA (and most others) have concerns regarding the jet bridge-to-engine distance with 2L. I believe there is a jet bridge modification (used by LH) that can be installed to support jet bridge boarding from 2L on the A321.
-FlyerBeek