Honeywell APU 131-9 AUTO & EMER. Shutdown difference?
 

Hi everyone,

I'm confusing about the difference regarding the difference btw 2 types of APU Protective Shutdown, these are as much as I know for now:
- AUTO S/D: No cool down cycle, ECB removes power from solenoids and torque motor, then roll down, Inlet Flap closes after 15 mins.
- EMER. S/D: pretty much the same as AUTO S/D, except the status of the Inlet Flap is unknown (not described in the AMM, or I haven't found it yet).

Is anyone know the operational difference btw these 2 mode? Is Emergency shutdown sequence faster than Auto shutdown?

Thank you.