737 NG pressure controller question.

[j3cubcapt]

Hey out there. I had a student ask me when the controllers of the digital 737NG pressurization switch. I know its on each landing, but is it a PSEU function or at engine shutdown or actually the touch down?

Any info will be helpful.

Thanks

J3:confused:

[Phoenix_X]

I'm not sure, but I think it's on engine shutdown....

[Denti]

I'm flying only the classic version (DCPCS though) but the pressure controller might work similar to the one used in the NG. According to our manual "while taxiing in, the pressure controller drives the outflow valve slowly to full open position depressurizing the cabin when N1 is less than 50%. Having the main outflow valve full open also prevents the equipment cooling fan from depressurizing the airplane to a negative pressure."

[DoctorA300]

Hi,
The DCPC's switch 60 seconds after "Depress" mode is completed , A/C on ground and no thrust lever above 30 degrees.
Hopes this helps
Brgds
Doc

[j3cubcapt]

Thanks for the great info response guys! I have looked in the Maint Manual and could not find a ref.

Thanks again and if you get any more info please post!

J3:D