Hi All

I have to be missing something but I'm just not certain what it is. I've got an initial cruise altitude of FL430. I dial in the baro, put in my FL + 1,000ft so in this case it's set to FL440 on the turn knob for the pressurization, I verify on the center console on the first officer side that it's locked into auto, but as soon as I go above FL400 (typically around there), my cabin alarm starts going off because the auto feature is no longer keeping cabin altitude. I manually have to change the rate knob to make the cabin decrease to stay around the 7,500ft cabin altitude range. 

The simple question... what am I doing wrong? I've watched some youtube videos to which I never see what people actually dial into the pressurization knob so I can't see what maybe I'm missing there.

On the normal procedures check list, i see page 6 > center > cabin pressure > rate knob = white dot, baro setting 29.92, cabin 0ft. Then on page 14 it just has cabin pressure controller = set. Page 18 again is just cabin pressure = checked. 

 

Let me know what other questions may arise. Thank in advance.

 

Mark Carter

You're not doing anything wrong. This is consistent with all Carenado aircraft that fly above 40,000 feet. They haven't been able to get the pressurization right on pretty much every AC they've made that has non-automatic settings.

On 2/15/2019 at 5:07 PM, endeavor384 said:

Hi All

I have to be missing something but I'm just not certain what it is. I've got an initial cruise altitude of FL430. I dial in the baro, put in my FL + 1,000ft so in this case it's set to FL440 on the turn knob for the pressurization, I verify on the center console on the first officer side that it's locked into auto, but as soon as I go above FL400 (typically around there), my cabin alarm starts going off because the auto feature is no longer keeping cabin altitude. I manually have to change the rate knob to make the cabin decrease to stay around the 7,500ft cabin altitude range. 

The simple question... what am I doing wrong? I've watched some youtube videos to which I never see what people actually dial into the pressurization knob so I can't see what maybe I'm missing there.

On the normal procedures check list, i see page 6 > center > cabin pressure > rate knob = white dot, baro setting 29.92, cabin 0ft. Then on page 14 it just has cabin pressure controller = set. Page 18 again is just cabin pressure = checked. 

 

Let me know what other questions may arise. Thank in advance.

 

Mark Carter

Long story short, you have to keep on eye on where your cabin altitude is and then stop it once it reaches your desired altitude.  If your altitude goes above normal it should let you decrese the rate down to normal levels.  I have found that sometimes I have zero control over the pressurization so I just hit the mute button to shut the cabin alert message off and pretend like my passengers aren't unconscious or dead 🙂