Lear 31 flight crew experiences altitude deviation while dealing with pressurization emergency.

Attributes
ACN	773560
Time
Date	200802
Place
Locale Reference	atc facility : zbw.artcc
State Reference	NH
Altitude	msl single value : 22000
Environment
Flight Conditions	IMC
Weather Elements	Rain Thunderstorm Ice Windshear Turbulence Fog
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zbw.artcc
Operator	common carrier : air taxi
Make Model Name	Learjet 31
Operating Under FAR Part	Part 91
Flight Phase	climbout : vacating altitude
Flight Plan	IFR
Person 1
Affiliation	company : air taxi
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 300 flight time total : 19000 flight time type : 80
ASRS Report	773560
Person 2
Affiliation	company : air taxi
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 120 flight time total : 4500
ASRS Report	773776
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

During climb to FL220 as assigned by ATC (center); we experienced aural sign of pressurization fail mode. Attempted to control cabin pressurization in automatic; manual; and emergency mode without results. As copilot is dealing with the emergency and emergency checklist; including oxygen masks; climbing through FL180; we failed to adjust the altimeter setting to 29.92 and; therefore; we had an altitude deviation by the time the altimeter was reset to 29.92. This aircraft had just been released from scheduled routine maintenance. The maintenance included phase inspections along with dual engine major periodic inspections; left windshield change and numerous discrepancies. My observations from the cabin is that the cabin would not pressurize at 17000 ft; the aural warning and annunciator illuminated. The PIC followed the emergency checklist to alleviate the issue; with the crew oxygen mask donned the pressurization system would not operate in any command mode; normal; manual or emergency. Supplemental information from acn 773776: during climb as assigned by ATC (center); we experienced problems with the pressurization system. As copilot; I was dealing with the emergency and the emergency items on the emergency checklist. While dealing with the emergency at hand; I did not put the 29.92 as standard altimeter setting in and; therefore; we had an altitude deviation.

Original NASA ASRS Text

Title: LEAR 31 FLT CREW EXPERIENCES ALTITUDE DEVIATION WHILE DEALING WITH PRESSURIZATION EMERGENCY.

Narrative: DURING CLB TO FL220 AS ASSIGNED BY ATC (CTR); WE EXPERIENCED AURAL SIGN OF PRESSURIZATION FAIL MODE. ATTEMPTED TO CTL CABIN PRESSURIZATION IN AUTOMATIC; MANUAL; AND EMER MODE WITHOUT RESULTS. AS COPLT IS DEALING WITH THE EMER AND EMER CHKLIST; INCLUDING OXYGEN MASKS; CLBING THROUGH FL180; WE FAILED TO ADJUST THE ALTIMETER SETTING TO 29.92 AND; THEREFORE; WE HAD AN ALTDEV BY THE TIME THE ALTIMETER WAS RESET TO 29.92. THIS ACFT HAD JUST BEEN RELEASED FROM SCHEDULED ROUTINE MAINT. THE MAINT INCLUDED PHASE INSPECTIONS ALONG WITH DUAL ENG MAJOR PERIODIC INSPECTIONS; L WINDSHIELD CHANGE AND NUMEROUS DISCREPANCIES. MY OBSERVATIONS FROM THE CABIN IS THAT THE CABIN WOULD NOT PRESSURIZE AT 17000 FT; THE AURAL WARNING AND ANNUNCIATOR ILLUMINATED. THE PIC FOLLOWED THE EMER CHKLIST TO ALLEVIATE THE ISSUE; WITH THE CREW OXYGEN MASK DONNED THE PRESSURIZATION SYS WOULD NOT OPERATE IN ANY COMMAND MODE; NORMAL; MANUAL OR EMER. SUPPLEMENTAL INFO FROM ACN 773776: DURING CLB AS ASSIGNED BY ATC (CTR); WE EXPERIENCED PROBS WITH THE PRESSURIZATION SYS. AS COPLT; I WAS DEALING WITH THE EMER AND THE EMER ITEMS ON THE EMER CHKLIST. WHILE DEALING WITH THE EMER AT HAND; I DID NOT PUT THE 29.92 AS STANDARD ALTIMETER SETTING IN AND; THEREFORE; WE HAD AN ALTDEV.

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.