PC12 captain reported diverting to a nearby alternate after a loss of cabin pressure.

Attributes
ACN	1321228
Time
Date	201512
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	PC-12
Operating Under FAR Part	Part 135
Flight Phase	Climb
Route In Use	Direct
Flight Plan	IFR
Component
Aircraft Component	Pressurization System
Person 1
Function	Pilot Flying Captain Check Pilot
Qualification	Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Instructor
Experience	Flight Crew Last 90 Days 100 Flight Crew Total 5000 Flight Crew Type 650
Events
Anomaly	Aircraft Equipment Problem Less Severe

Narrative:

Climbing through FL210 we received a caution for part of our pressurization system. We completed the checklist which momentarily cleared the malfunction. Seconds later it returned with a decompression with the cabin rate climbing about 1;700-2;000 FPM. My first officer; our passengers and I put on our oxygen masks and I completed an emergency descent. [I advised ATC] and I elected to divert to the closest airport. No further issues occurred; no limitations aside from differential pressure were exceeded.

Original NASA ASRS Text

Title: PC12 Captain reported diverting to a nearby alternate after a loss of cabin pressure.

Narrative: Climbing through FL210 we received a caution for part of our pressurization system. We completed the checklist which momentarily cleared the malfunction. Seconds later it returned with a decompression with the cabin rate climbing about 1;700-2;000 FPM. My first officer; our passengers and I put on our oxygen masks and I completed an emergency descent. [I advised ATC] and I elected to divert to the closest airport. No further issues occurred; no limitations aside from differential pressure were exceeded.

Data retrieved from NASA's ASRS site 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.