Dick,
The JAA and FAA codes (which are nearly, but not quite the same) are downloadable at...
http://www.jaa.nl/jar/jar.html For JAA Codes
and...
http://www.faa.gov/avr/AFS/FARS/far_idx.htm For FAA codes.
The JAA codes site is a bit more user-friendly, but the FAA site contains all the interpretative information. The JAA site is generally better for the diagrams.
Frankly, for teaching ATPL students, if I were you, I'd stick to part 23 - part 25 is full of additional engineering detail which, apart perhaps from a few elements in the performance section, won't really add anything useful to a pilot's knowledge.
Incidentally I've been thinking deeper thoughts about this. I
think
that the A2 point on the part 25 diagram is just there so that design teams, should they wish, can reduce Va with smaller flight weights. This is in one light valid, since by doing so, you'll ensure that the permitted g-loadings are not exceeded. However, in practice, the g-loadings are determined at MTOW, and reaching a bit more g, at Va, at a lower weight, actually will still impose the same overall loads upon the airframe - so that would really just be a case of extra operating requirements for no particularly good reason.
Then again, much of the JAA seems to be run on that premise, or am I getting cynical in my old age ?
G
N.B. If you're down at Gloucester and want the odd groundschool lecture for your studes, I'm reasonably local and open to offers.
[ 11 December 2001: Message edited by: Genghis the Engineer ]