Hi FlightDetent,
This is a glitch. We have the same issue in our NEOs fleet. First flight of day: No cooling required on engine 1 but always cooling required on engine 2. I can email you the document but the reason given by Airbus is:
COOLING time can be displayed on one engine and not on opposite one
while both engines shutdown at same time/slot. This can occur for the first
start of the day, especially when bow effect is low or null, considering
engine thermal status. In that case, it would have been expected to not
have any required engine cooling or MtS.
This is due to MS failsafe value set, caused by engine OFF counter validity
lost.
The clock disagree is the main issue leading to inconsistent MtS, like
failsafe value while not required due to long TAT.
This clock disagree can occur at either A/C power OFF or a A/C
power ON. Identified causes are:
Clock unsynchronized at A/C power OFF (GPS mode vs
internal),
Clock invalidity at one EIU during EIU/EEC initialization (indeed
both EIU may not initialized at same speed); this leads to one
EIU gets ready earlier than the other while clock inputs not yet
valid. Therefore, EIU requires failsafe MtS.
Improvements