Hi All,

Today I was up flying and figuring out the pressurization system.  Things like if the annunciator panel / warning horn would sound if the "dump" switch was in the on (don't pressurize position).

As I climbed through 11,000' the horn and annunciator panel lit up.  I could see that the system wasn't pressurized as the gauge indicated the cabin pressure at pretty much the same as our altitude (we were at 11k and the cabin showed 10k).   The dial was set to the 1000' field elevation.    I flicked the dump switch and the cabin immediately began to pressurize (I could feel it in my ears almost immediately after flicking the switch).  I then climbed to 14000' to see how the system would react (Power setting 28" and 2300RPM).   At 14,000' the pressurization horn went off again as the cabin pressure got to 10,000' again.  I realized that I forgot to change the dial to my cruising altitude of 14,000', so I then dialed up 14000', thinking that the pressurization system would then pressurize to that new altitude --- but it didn't.  It just stayed at a cabin pressure of 10k.

I have a couple questions... 

1)  I presume the cabin pressurization should be set to my cruise altitude BEFORE I get there as turning the dial to my cruising altitude after I get there doesn't seem to work... is this right?

2)  People have told me that I should set the pressurization 1000' above my actual cruising altitude and field elevation on landing... is this right?  Whats the logic here?

Thanks,

Dico