An MD83 was dispatched in non compliance with the incorrect cabin pressure selector installed.

Attributes
ACN	600813
Time
Date	200311
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Environment
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	MD-83
Operating Under FAR Part	Part 121
Flight Phase	ground : maintenance
Person 1
Affiliation	company : air carrier
Function	maintenance : technician
Qualification	technician : airframe technician : powerplant
ASRS Report	600813
Person 2
Affiliation	company : air carrier
Function	maintenance : lead technician
Qualification	technician : powerplant technician : airframe
ASRS Report	600812
Events
Anomaly	aircraft equipment problem : critical maintenance problem : improper documentation maintenance problem : improper maintenance non adherence : published procedure non adherence : far
Independent Detector	aircraft equipment other aircraft equipment : cabin pressure indicator
Resolutory Action	none taken : detected after the fact
Consequence	other other
Factors
Maintenance	contributing factor : non availability of parts performance deficiency : installation performance deficiency : non compliance with legal requirements performance deficiency : logbook entry
Supplementary
Problem Areas	Maintenance Human Performance Chart Or Publication Company Aircraft
Primary Problem	Maintenance Human Performance

Narrative:

On a gate call to aircraft X I determined the cabin pressure selector was defective. I was told the proper selector was nis (not in stock). My crew chief called technical services for a placard. I was informed by my crew chief that the part was integrated so was interchangeable with cpn sel XXXX company X part. I, myself did not check the aircraft effectivity, but relied on these 2 individuals as I was on the gate. I installed sel XXXX and the part passed the 'alternate method' operational check per maintenance manual. I signed off the discrepancy in the logbook. After takeoff the aircraft could not automatic-pressurize. Upon further research in the illustrated parts catalog, my crew chief and I found that the wrong part had been installed. The improper part was brought to me by another mechanic under instruction from the crew chief.

Original NASA ASRS Text

Title: AN MD83 WAS DISPATCHED IN NON COMPLIANCE WITH THE INCORRECT CABIN PRESSURE SELECTOR INSTALLED.

Narrative: ON A GATE CALL TO ACFT X I DETERMINED THE CABIN PRESSURE SELECTOR WAS DEFECTIVE. I WAS TOLD THE PROPER SELECTOR WAS NIS (NOT IN STOCK). MY CREW CHIEF CALLED TECHNICAL SVCS FOR A PLACARD. I WAS INFORMED BY MY CREW CHIEF THAT THE PART WAS INTEGRATED SO WAS INTERCHANGEABLE WITH CPN SEL XXXX COMPANY X PART. I, MYSELF DID NOT CHK THE ACFT EFFECTIVITY, BUT RELIED ON THESE 2 INDIVIDUALS AS I WAS ON THE GATE. I INSTALLED SEL XXXX AND THE PART PASSED THE 'ALTERNATE METHOD' OPERATIONAL CHK PER MAINT MANUAL. I SIGNED OFF THE DISCREPANCY IN THE LOGBOOK. AFTER TKOF THE ACFT COULD NOT AUTO-PRESSURIZE. UPON FURTHER RESEARCH IN THE ILLUSTRATED PARTS CATALOG, MY CREW CHIEF AND I FOUND THAT THE WRONG PART HAD BEEN INSTALLED. THE IMPROPER PART WAS BROUGHT TO ME BY ANOTHER MECH UNDER INSTRUCTION FROM THE CREW CHIEF.

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.