737ng Cargo Door
 

HELLO ALL,
on the 737 qrh about cargo door (aft or fwd), there are two options. if tere is no pressurization problem than continue normal flt, if there is pressurization problem, acft should be decended and the crew have to decrease the diff press. to zero.
the question is what is the reason for zero diff press.?

Edit.
Post removed due technical error.

On The 737 The Cargo
 

The Cargo Doors Opens Inside The Cargo Compartment.

Hi 1Big,

Thanks - I'd forgotten 737 cargo doors open inwards. In that case - I don't know why it asks for zero diff pressure.

Picture of the CL's outward opening door.
The Boeing 737 Technical Site Convertible

Edit: Found a C-40 http://www.b737.org.uk/images/c-40ascd.jpg

Just thinking aloud here,

maybe the NNCL assumes that if pressurisation is not normal then there is a potential structural problem with the door and therefore reducing the diff will reduce stress on the door and fuselage etc?

As its a plug door, if there was no structural problem then pressurisation should be normal?

As I said, just thinking aloud.

Dave.

In our OM part B it says the zero diff press is to protect the cabin floor. When the door would completely fail with the aircraft still pressurized this would cause such a rush of air that it might let the cabin floor collapse.

This situation has happened before on a DC 10 of Turkish airlines:
Turkish Airlines Flight 981 - Wikipedia, the free encyclopedia

737ng Cargo Doors
 

HI,
thank you for the response.
does your OM is for the 737 ng?

yup B737 classic & NG