Thanks to everyone in this thread, there is some very useful information here. A comment and a question...
Before the most recent 13 Nov (or so) update to DCS, I was not getting any of the triggers for the random failures (CDU, AC gen, hydro, etc) -- even waiting for the failure until the instructor said "you failed to do that correctly...". This occurred in both the practice and actual missions. Since the update, all of the triggers seem to be present again, which is great! Whether it was the update or I needed some repair to my installation, I do not know.
Anyways, the other thing that occurred with the update is that I had my first experience with the erratic behaviour (probably because the hydraulics never went out before!). With the help of this thread, I managed to keep everything under control and was able to land well.
I wondered about the scoring, if I may ask? I always get a Q-minus. I can let go of my perfectionism, but I am curious what I must be doing wrong. For navigation and maneuvers, I receive Q-, but everything else is Q. I am not breaking speed, altitude or heading during any part of the flight. However, of course, I have some erratic behaviour once both hydro failures occur. Could this be taken into account in the scoring? If it's not possible to obtain a Q on this, I will move on, but if it is, I usually keep practicing until I get it. It seems to be beneficial.
Many thanks!