If a single chime or any other abnormal situation arises: reengage automation immediately. You can enjoy and practice another day.
There is two ways of interpreting the above:
number 1:
Doesn't that say it all? Wasn't it one of the recent 737 crashes where the captain was heard screaming on the CVR "engage the autopilot - engage the autopilot" as he was in a steep spiral dive in IMC and killed everyone aboard
number 2:
If you are practicing a No FD take off, and then you have a single chime with a "
AIR ENG BLEED ABNORNM
PR" or "
FLT CTL SLATS FAULT" caution, or if there is significant engine vibration, or if there is a mess with the communications, wrong frequencies, or something with a possibility of loss of separation, or many other possible situations where it is better to make full use of automation while relieving PF's (and PM's) brain so that the team's situational awareness is optimal and becomes more efficient for managing the situation...
In this cases, reengage the bloody AP/FD and A/THR.
I meant number 2, it goes without saying