Cpr aircraft has pressurization problem. Gains control.

Attributes
ACN	272436
Time
Date	199405
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : ord
State Reference	IL
Altitude	msl bound lower : 37000 msl bound upper : 39000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zau tower : roa
Operator	general aviation : corporate
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 91
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 50 flight time total : 9000 flight time type : 350
ASRS Report	272436
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : critical altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency flight crew : overcame equipment problem
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Aircraft

Narrative:

Sent our pressurization controller out for repair. Used a loaner for ayr. Received our controller back and had installed. While at 39000 ft, the cabin began to rise and told center we needed lower. Then the cabin rapidly rose and the masks dropped. Started out of altitude. 370 was given by center but we have left altitude before received as the problem got worse. Gained control of the cabin about 10 seconds after the incident actually occurred. As all seemed to work out just fine, and center just asked why we needed lower, which we told them, this may have just been a 300 ft altitude busts, but whatever, we needed lower immediately. Quite amazingly, none of the passenger, of which all are seasoned flyers, put their masks on. A program is now being developed for passenger survival training besides just the video and verbal instruction.

Original NASA ASRS Text

Title: CPR ACFT HAS PRESSURIZATION PROB. GAINS CTL.

Narrative: SENT OUR PRESSURIZATION CTLR OUT FOR REPAIR. USED A LOANER FOR AYR. RECEIVED OUR CTLR BACK AND HAD INSTALLED. WHILE AT 39000 FT, THE CABIN BEGAN TO RISE AND TOLD CTR WE NEEDED LOWER. THEN THE CABIN RAPIDLY ROSE AND THE MASKS DROPPED. STARTED OUT OF ALT. 370 WAS GIVEN BY CTR BUT WE HAVE LEFT ALT BEFORE RECEIVED AS THE PROB GOT WORSE. GAINED CTL OF THE CABIN ABOUT 10 SECONDS AFTER THE INCIDENT ACTUALLY OCCURRED. AS ALL SEEMED TO WORK OUT JUST FINE, AND CTR JUST ASKED WHY WE NEEDED LOWER, WHICH WE TOLD THEM, THIS MAY HAVE JUST BEEN A 300 FT ALT BUSTS, BUT WHATEVER, WE NEEDED LOWER IMMEDIATELY. QUITE AMAZINGLY, NONE OF THE PAX, OF WHICH ALL ARE SEASONED FLYERS, PUT THEIR MASKS ON. A PROGRAM IS NOW BEING DEVELOPED FOR PAX SURVIVAL TRAINING BESIDES JUST THE VIDEO AND VERBAL INSTRUCTION.

Data retrieved from NASA's ASRS site as of July 2007 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.