There are two basic models of the BSA airborne bicycle. I have arbitraily
called them "early" and "late".
In the UK some collectors have noted other differences, but there is not
enough information to create full catagories.
It may be that there is the "very early" variation, and possibly
even a "very late" version.
Much more research needs to be done.
So far there is no indication of "Marks" terminology being applied
to these bikes.
Then there are the post-war derivatives.
For more information, click on bars to your left.