I have never traveled by plane with my AeroZ. I suspect it would not hold up under rough treatment as well as a titanium chair; I am quite gentle with mine. Ask SCI_OTR for his recommendation regarding a chair for air travel; he often travels by air. If I traveled often by air, I would want a TR3 with a welded backrest.
My understanding is the initial Series2 folding backrest issues have been resolved for new chairs. (Some older S2 chairs stll have the bad hardware.)
DU00019 is TiLite's
Designs Unlimited code for a fixed backrest. (The DU00019 page says it's for only the ZR, but the DU table of contents says it's for ZR, ZRA, and AeroZ). I will call them later today (when they're open) to confirm that for you.
Chas