Hi D.O.G.,
Thanks very much for your very comprehensive reply, much appreciated

.
I am actually joining an engine company on their Graduate engineering program later this year, and am looking ultimately at heading toward the Flight Ops Performance or Flight Test professions, and thought it wise to get a heads-up on this.
I've seen a few of the things you've mentioned; others I haven't, so will take a look at those. If you do have a soft copy of the Boeing Performance course notes, I'd really appreciate it if you could send them my way (I'll PM you my e-mail add. if you do have them).
I've had a look at the short course/CPDA avenue, which on my current budget is a bit of a stretch, as I'd be self-funding; once I start with said engine company, I'll try my best to get them to fund it!
Once again, thanks so much for your info which most certainly is helpful, and if you do have the Boeing notes, that would be great.
Cheers ....... fbw380