777 did the same, as does the A330.
APU slows to about 82% during the cooldown, switch it back on and up it goes back to 100%.
During the 85 second cooldown you have the opportunity to switch it back on.
Note: if you weren’t using the bleed air there isn’t a cooldown, it shuts down after 15 seconds ( A330 )
Last edited by ACMS; 18th February 2018 at 06:09.