Thanks very much everyone for your help so far. I should probably clarify a little better what information is needed, and why it's needed.
We build airborne data acquisition systems which are used by civil aviation authorities (like FAA) to test and certify ground-based aircraft radio...
Thanks very much.
I should have clarified though, I'm mostly looking for data for small and mid size business aircraft.
Examples: King Air B200, C90, B1900, Cessna Citation, Lear 35's and so forth.
Does anyone know where I can find a DB-25 breakout box? I've seen a few that let you switch a pin on/off, but what I really need is one with posts where you can clip on a scope probe.