Can someone tell me the difference between the Ba Medical and JAA class one? :)

Differences:

BA's audiometric test is slightly different.
BA take blood samples and test them.
Eyesight is not done by an optometrist at BA, it's just done using a letters board and a nurse.
There is no chest x-ray at BA.
Some areas are more strict at BA as stated in the BA literature.

Hope this helps, e-mail me for more info if you need it.

SB