Cabin pressure
Tekata and others.
I found the following statements in one of my files:
"Report No: 4/2009. Report on the serious incident to Airbus A319-111, registration G-EZAC, near Nantes, France on 15 September 2006
Loss of both airspeed data sources due to loss of the power supplies to ADIRUs 1 and 3.... ADIRU:s 1 and 3 feed data to the cabin pressure controllers. De-energisation of the AC BUS 1 and AC ESS busbars prevents CPC 1 and CPC 2 from operating, because of the loss of power and loss of ADIRU data. Cabin pressurisation would then need to be controlled manually by the crew. The excess cabin altitude warning system would still be operational....
Other significant systems were affected, such as the cabin pressurisation system, where the automatic control function was no longer available. In this incident it did not cause the flight crew any difficulty, however had this failure occurred in other circumstances, the cabin altitude could increase excessively, requiring corrective action. The flight crew would then have to control the cabin pressure manually. Whilst the excessive cabin altitude warning would still operate, it would not be possible to deploy the passenger oxygen masks.
"
Hence, in the cited case it may be possible to have a loss of hull pressure without oxygen mask deployment.