PDA

View Full Version : A320 Pressurisation Profile


Boeingdriver999
5th May 2023, 13:05
Hi all,

Looking at FCOM DSC 21-20-30; it quotes a ROC/ROD and a differential of +0.1 PSI in both climb and descent.

My question regarding descent: the aircraft begins a descent and descends the cabin at a ROD. If you are descended very early and fly level for a period does this mean it then stops the cabin descent and maintains the differential at +0.1 PSI? In other words; cabin altitude correlates with aircraft altitude?

Thanks

AerocatS2A
5th May 2023, 16:29
You are misreading the diagram. The rate of climb/descent to 0.1 psi is on the ground and is part of its prepressurisation/ depressurisation profile. Airborne the cabin is always pressurised as you can see on the level segments shown.

Boeingdriver999
5th May 2023, 20:35
Ah gotcha, I see it now. Any clue as to the question?

AerocatS2A
5th May 2023, 20:41
Ah gotcha, I see it now. Any clue as to the question?
It looks like it keeps descending until it gets to max differential or the destination field elevation +0.1.