An AC690 captain experienced a cabin altitude warning passing through FL230 during climb. A descent ...

Attributes
ACN	946651
Time
Date	201104
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Turbo Commander 690 Series
Operating Under FAR Part	Part 91
Flight Phase	Climb
Route In Use	Direct
Flight Plan	IFR
Component
Aircraft Component	Pressurization System
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine Flight Crew Flight Engineer
Experience	Flight Crew Last 90 Days 6 Flight Crew Total 32000 Flight Crew Type 55
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

Climbing through FL230 cabin altitude alert illuminated indicating cabin was 14;000 and climbing. Donned oxygen mask and made determination that we couldn't stop the cabin from climbing. Advised center we needed immediate descent to 14;000 ft. We were unable to get immediate clearance below our current altitude and center was talking to another aircraft so I initiated a descent after checking TCAS to ascertain no aircraft in our vicinity. Cabin was climbing rapidly. Shortly after starting down we received the clearance. I 'think' at that time I was passing FL225; not too sure as I was very busy. It appeared our bleed valves were closed although the mode switch was in auto. [We] did our trouble shooting after level at 14;000. Center asked if we were declaring an emergency but by that time we were at 14;000 and it was no longer necessary so we declined. Pressurization was holding at that point; continued flight at 14;000 to destination. No more was said from center.

Original NASA ASRS Text

Title: An AC690 Captain experienced a cabin altitude warning passing through FL230 during climb. A descent was commenced before clearance was received and flight continued to destination at 14;000 FT.

Narrative: Climbing through FL230 cabin altitude alert illuminated indicating cabin was 14;000 and climbing. Donned oxygen mask and made determination that we couldn't stop the cabin from climbing. Advised Center we needed immediate descent to 14;000 FT. We were unable to get immediate clearance below our current altitude and center was talking to another aircraft so I initiated a descent after checking TCAS to ascertain no aircraft in our vicinity. Cabin was climbing rapidly. Shortly after starting down we received the clearance. I 'think' at that time I was passing FL225; not too sure as I was very busy. It appeared our bleed valves were closed although the mode switch was in Auto. [We] did our trouble shooting after level at 14;000. Center asked if we were declaring an emergency but by that time we were at 14;000 and it was no longer necessary so we declined. Pressurization was holding at that point; continued flight at 14;000 to destination. No more was said from Center.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

An AC690 captain experienced a cabin altitude warning passing through FL230 during climb. A descent was commenced before clearance was received and flight continued to destination at 14;000 ft.