Narrative:

The affected aircraft arrived with the WX radar/terrain inoperative and deferred. Dispatch refused to continue its current routing due to WX. Through troubleshooting, I narrowed the problem down to the enhanced GPWS computer. The computer was out of stock at my station and I was instructed by my supervisor to rob one from a plane that was going OTS. I robbed the part without positively matching the part numbers, assuming they were the same. Installing the robbed part did not fix the problem. I attempted to retrieve the original part but the aircraft had already departed for the hangar. I was still unaware of the wrong part. The aircraft was rerted with the WX/terrain still deferred. When the deferred item was worked on during overnight maintenance, they discovered the wrong part number was installed. They installed the proper egpws computer and cleared the deferred item. They then informed me of my error.

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Original NASA ASRS Text

Title: A B737-500 WAS DISPATCHED IN NON COMPLIANCE WITH THE INCORRECT GPWS COMPUTER INSTALLED.

Narrative: THE AFFECTED ACFT ARRIVED WITH THE WX RADAR/TERRAIN INOP AND DEFERRED. DISPATCH REFUSED TO CONTINUE ITS CURRENT ROUTING DUE TO WX. THROUGH TROUBLESHOOTING, I NARROWED THE PROB DOWN TO THE ENHANCED GPWS COMPUTER. THE COMPUTER WAS OUT OF STOCK AT MY STATION AND I WAS INSTRUCTED BY MY SUPVR TO ROB ONE FROM A PLANE THAT WAS GOING OTS. I ROBBED THE PART WITHOUT POSITIVELY MATCHING THE PART NUMBERS, ASSUMING THEY WERE THE SAME. INSTALLING THE ROBBED PART DID NOT FIX THE PROB. I ATTEMPTED TO RETRIEVE THE ORIGINAL PART BUT THE ACFT HAD ALREADY DEPARTED FOR THE HANGAR. I WAS STILL UNAWARE OF THE WRONG PART. THE ACFT WAS RERTED WITH THE WX/TERRAIN STILL DEFERRED. WHEN THE DEFERRED ITEM WAS WORKED ON DURING OVERNIGHT MAINT, THEY DISCOVERED THE WRONG PART NUMBER WAS INSTALLED. THEY INSTALLED THE PROPER EGPWS COMPUTER AND CLRED THE DEFERRED ITEM. THEY THEN INFORMED ME OF MY ERROR.

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.