Narrative:

Night VMC on an IFR flight plan; with 8 passenger on board. We were at 13000 ft MSL on the arrival into ZZZ when the cabin pressurization failed in the automatic mode and allowed the cabin pressure to drop; activating the emergency pressurization. We complied with the appropriate checklist and requested a lower altitude. We notified approach that we would be unable to comply with the arrival altitudes and needed a reroute to avoid mountainous terrain. Approach was unable to reroute us; thus we exercised command authority/authorized and declared an emergency; and asked for direct to ZZZ airport. At that time the airport was in sight; and we were cleared down to 10000 ft. The cabin pressure stabilized at the lower altitude and a landing was made visually without further incident. The inability to receive an immediate reroute from ZZZ controllers prompted the declaration of an emergency in order to deviate from the STAR restrs for altitude clearance over mountainous terrain at night. (As information; this arrival routing is over mountainous terrain; where our current direct routing at that time was direct to the airport and not over mountainous terrain.)

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Original NASA ASRS Text

Title: LEAR 35 PRESSURIZATION CONTROL FAILED. FLT CREW DECLARED EMER; APCH AND LNDG COMPLETED UNEVENTFULLY.

Narrative: NIGHT VMC ON AN IFR FLT PLAN; WITH 8 PAX ON BOARD. WE WERE AT 13000 FT MSL ON THE ARR INTO ZZZ WHEN THE CABIN PRESSURIZATION FAILED IN THE AUTO MODE AND ALLOWED THE CABIN PRESSURE TO DROP; ACTIVATING THE EMER PRESSURIZATION. WE COMPLIED WITH THE APPROPRIATE CHKLIST AND REQUESTED A LOWER ALT. WE NOTIFIED APCH THAT WE WOULD BE UNABLE TO COMPLY WITH THE ARR ALTS AND NEEDED A REROUTE TO AVOID MOUNTAINOUS TERRAIN. APCH WAS UNABLE TO REROUTE US; THUS WE EXERCISED COMMAND AUTH AND DECLARED AN EMER; AND ASKED FOR DIRECT TO ZZZ ARPT. AT THAT TIME THE ARPT WAS IN SIGHT; AND WE WERE CLRED DOWN TO 10000 FT. THE CABIN PRESSURE STABILIZED AT THE LOWER ALT AND A LNDG WAS MADE VISUALLY WITHOUT FURTHER INCIDENT. THE INABILITY TO RECEIVE AN IMMEDIATE REROUTE FROM ZZZ CTLRS PROMPTED THE DECLARATION OF AN EMER IN ORDER TO DEVIATE FROM THE STAR RESTRS FOR ALT CLRNC OVER MOUNTAINOUS TERRAIN AT NIGHT. (AS INFO; THIS ARR ROUTING IS OVER MOUNTAINOUS TERRAIN; WHERE OUR CURRENT DIRECT ROUTING AT THAT TIME WAS DIRECT TO THE ARPT AND NOT OVER MOUNTAINOUS TERRAIN.)

Data retrieved from NASA's ASRS site as of May 2009 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.