Originally Posted by
AerocatS2A
5 minutes warm up is required after 2 hours of not running to prevent thermal shock. There is no requirement to warm up the engines after a short turn-around, however there is a requirement to wait 2 minutes (not 3) after the last engine start to give the centre tank pumps time to complete their self test. MSNs that don’t have centre tank pumps don’t have this requirement so there is no minimum wait time after start in this case. In our fleet this includes late model CEOs and all NEOs.
Refer to FCOM PRO-NOR-SOP-AFTER START.
You can identify aircraft without centre tank pumps by the overhead panel. If the centre tank transfer switches are labelled “PUMP” then they are mechanical pumps, if they are labelled L/R XFR then they are jet pumps and don’t have the self test requirement.
My company is in the proces of getting the FCOM. Currently using AOM+COM. Haven't read the whole FCOM yet, as it just came out last week and won't be controlling till March earliest. Our current and controlling manual has in AOM2-Normal Procedures-Taxi Expanded:
"When Engine 2 reaches idle, continue flow:
Consider starting the CHRONO to monitor
engine warm-up time:
Shutdown for ≥ 2 hrs 5 min before high power.
Shutdown for < 2 hrs 3 min before takeoff."
Now, this might be because we try to fly the NEOs and CEOs the same, but it is in my book, and has nothing to do with the 2 minute center tank thing for the older CEOs.