A320 APU
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A320 APU
Why this change in N% (Honeywell 131-9)
The ECB always sets the APU speed to 100 % except for air conditioning demand, if the ambient temperature is between -18 °C and 35 °C. In this case, the ECB sets the APU speed to 99 %. For all other ambient temperatures (less than -18 °C or more than 35 °C), the ECB sets the APU speed to 100 %.
On the APS3200
In the case of an automatic, non-emergency shutdown, the air inlet flap closes 15 min after the APU speed is lower than 7%. If an automatic, non-emergency shutdown happens on ground, the 15 min countdown starts after liftoff.
Why the delay ?
The ECB always sets the APU speed to 100 % except for air conditioning demand, if the ambient temperature is between -18 °C and 35 °C. In this case, the ECB sets the APU speed to 99 %. For all other ambient temperatures (less than -18 °C or more than 35 °C), the ECB sets the APU speed to 100 %.
On the APS3200
In the case of an automatic, non-emergency shutdown, the air inlet flap closes 15 min after the APU speed is lower than 7%. If an automatic, non-emergency shutdown happens on ground, the 15 min countdown starts after liftoff.
Why the delay ?
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737NG Pilot, never seen that delay on ground on A320. There is max 2 min cooldown cycle before APU shuts down (depends on bleed usage). Inlet flap closes immediately after APU rpm is less that 7%. Where did you find information about 15 minutes delay and could you please insert a quote from a document here? Could you also tell what do you mean under automatic shutdown? There is no automatic shutdowns on APU - it is either normal, protective or emergency.
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737NG Pilot, never seen that delay on ground on A320. There is max 2 min cooldown cycle before APU shuts down (depends on bleed usage). Inlet flap closes immediately after APU rpm is less that 7%. Where did you find information about 15 minutes delay and could you please insert a quote from a document here? Could you also tell what do you mean under automatic shutdown? There is no automatic shutdowns on APU - it is either normal, protective or emergency.
Last edited by aeo; 5th Apr 2022 at 08:36.
