Low Differential Pressure

TASK 21-31-00-810-810-A
Low Differential Pressure

1. Possible Causes

A high aircraft rate of descent (higher than 2000 ft/min)
An abnormal aircraft performance due to cabin altitude rate of sustained descent, from cruise altitude to landing, with no/little level off
A change of the selected LFE during descent
If the QFE/QNH is not updated after a large change of the barometric conditions on the landing field

2. Fault Confirmation
Subtask 21-31-00-710-069-A

A. Do a read out of the POST FLIGHT REPORT.

NOTE: The ECAM warning CAB PR LO DIFF PR appears if the differential pressure is approximately zero.

3. Fault Isolation
Subtask 21-31-00-810-070-A

A. If the POST FLIGHT REPORT gives a maintenance message, refer to the Fault Symptoms List for the applicable trouble shooting procedures.

Subtask 21-31-00-810-071-A

B. If the POST FLIGHT REPORT gives no maintenance message:

NOTE: The warning appeared as a result of:

A high aircraft rate of descent (higher than 2000 ft/min),
An abnormal aircraft performance due to cabin altitude rate of sustained descent, from cruise altitude to landing, with no/little level off,
A change of the selected LFE during descent ,
If the QFE/QNH is not updated after a large change of the barometric conditions on the landing field.

4. Close-up
Subtask 21-31-00-860-059-A

A. Put the aircraft back to its initial configuration.

[Rev.8 from Aug 2018] 2026.04.04 04:24:42 UTC