Does anyone know how to trick the computers to prevent the cabin pressure from going the wrong way after takeoff? My runway is at 3,800 MSL. When I go to a lower airport, the cabin starts down because I told the FMS that I was going to that airport. Then, after it gets to max diff, it starts going the right way, but now it needs 600-700 fpm to catch up. With a manual controller, I could just set a 400 fpm climb from the get go and I could maintain that comfortable rate all the way to cruise altitude. I've had auto pressure control in other planes, but always had a knob to set the cruise altitude before takeoff. Is this an issue with anyone else, or do I really have to get out the manual? I just figured out how to put the clocks on the PDFs.

What type aircraft do you have?

It's an M600.

why not initially put a higher airport (or none at all) in as the destination ? what does it do if you take off for a local flight with nothing programmed ?

Shouldn't you be grounded with wing spar issues?

I'm just guessing, but I would think the FMS might perhaps have a setting for cruise altitude somewhere? My guess would be that would be another input that the computer uses to choose cabin altitude.

In the pressurized airplanes I have flown, after takeoff the pressurization looks for the cruise altitude first. Can you set cruise altitude in the FMC?

If you do a turn back to the take off airport, the pressurization system goes back to that airport. If the flight is continued to cruise altitude, the cruise relay is tripped, and the cabin stays at that altitude which has been set in the FMC or a pressurization panel. Do you have a pressurization panel, or is everything taken from the FMC?

Then you start down, at a certain altitude below cruise setting, the pressurization goes to destination airport. Something does not seem correct in your situation. Have flown Boeing products that had a pressurization panel that had windows for takeoff field elevation, cruise alt., and arrival FE. There were other functions also.

EDIT: Looking at the Internet, it knows where it is and the elevation, and from the flight plan destination takes a FE from that. No mention of a cruise altitude setting, and just works from those two inputs. There must be more to it than 2 inputs. Anything in the flight manual about it? Also found a statement that you can go to the Systems Page and enter DEST ELEV.
Tony Randall

Like you sometimes miss the smoothness of the manual system. Seems like the same thing happened in the M2 and the Eclipse as well. I would use caution trying to trick the system though. Wouldn't be hard to imagine a scenario when you forgot about tricking it and landed pressurized. If you wish, you can change the destination elevation manually. That is in the settings, but be careful

Here is the page.

I am surprised the G3000 has no place to input the cruise altitude. Knowing the cruise altitude it would know how much to pressurize the cabin before it starts depressurizing for the destination field elevation.

I'm not sure that I see a problem. The only thing that I question is why the cabin would climb 600-700fpm after reaching max differential. That seems high, but your ROC might have had something to do with that.

I recently had a 25 minute flight from a 4,100 msl airport to a 500 msl airport. My cabin descended all the way to cruise altitude, and then descended more once I began my descent to land.

Yes, it is back at the service center having the SB addressed. In the 500, the controller was by my left knee and looked like every other controller except it had less than desirable lighting and required an additional source of illumination at night to see it. I've checked everywhere on the 600 and the Garmin book, but can't seem to find a way to put the cruise altitude in. It does everything else but make the coffee, but no cruise altitude. Somebody said it was the only single engine plane with the G3000 and I'm wondering if somebody just forgot that it should probably have a way to tell it that we're going to climb to 280 first. As for what will happen if I don't put a destination in, it wants me to accept a bunch of stuff before it will let me move on to other stuff. I was always told to program the FMS and accept initialization before taxi. Not like the G1000 where I would do all that while taxiing, and skip that weights and exceedances page with just a FOB sync. Thanks for all of the suggestions, guys. I'm going to send this one up the chain of command at the service center and see what they can find out.

My M500 had a computer controlled pressurization system. You had a manual controller in your M500? Didn't realize they came with those. My Meridian did have the manual controller though, was quite the ace with 300 fpm climbs and descents. In that bird there was an LED light that shined on the controller, that you could control from the overhead panel, could make it pretty bright if you needed.