A B737-700 was dispatched with the incorrect ground proximity warning computer installed.

Attributes
ACN	708254
Time
Date	200606
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	ground : maintenance
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	maintenance : technician
Qualification	technician : powerplant technician : fcc technician : airframe
Experience	maintenance lead technician : 2 maintenance repairman : 10 maintenance technician : 10
ASRS Report	708254
Person 2
Affiliation	company : air carrier
Function	oversight : coordinator
Events
Anomaly	aircraft equipment problem : critical maintenance problem : improper documentation maintenance problem : improper maintenance non adherence : far non adherence : published procedure
Independent Detector	other other : 1
Resolutory Action	none taken : detected after the fact
Consequence	other
Factors
Maintenance	contributing factor : manuals contributing factor : schedule pressure performance deficiency : installation performance deficiency : logbook entry performance deficiency : non compliance with legal requirements
Supplementary
Problem Areas	Aircraft Maintenance Human Performance Chart Or Publication Environmental Factor
Primary Problem	Maintenance Human Performance

Narrative:

30 mins warning of aircraft arriving with ground proximity computer inoperative as troubleshot by previous station. Maintenance control had set up a log with the part number computer requested (we assumed this to be correct part number). Part was ordered but we were unable to determine if the correct software was loaded. Not finding correct software at usual location; a drive to the hangar where all software is available was made to ensure the software was available for installation if required once the computer was changed. On returning from the hangar I was notified that the same aircraft would also have a WX radar write-up. This would be a 'must fix' -- 'aircraft shall not re-part.' after returning to the shop and completing the computer entries for the part changes; I discovered the wrong part number had been installed. I notified maintenance control immediately as the aircraft had left the gate. Correct part number computer was installed at the next station.

Original NASA ASRS Text

Title: A B737-700 WAS DISPATCHED WITH THE INCORRECT GND PROX WARNING COMPUTER INSTALLED.

Narrative: 30 MINS WARNING OF ACFT ARRIVING WITH GND PROX COMPUTER INOP AS TROUBLESHOT BY PREVIOUS STATION. MAINT CTL HAD SET UP A LOG WITH THE PART NUMBER COMPUTER REQUESTED (WE ASSUMED THIS TO BE CORRECT PART NUMBER). PART WAS ORDERED BUT WE WERE UNABLE TO DETERMINE IF THE CORRECT SOFTWARE WAS LOADED. NOT FINDING CORRECT SOFTWARE AT USUAL LOCATION; A DRIVE TO THE HANGAR WHERE ALL SOFTWARE IS AVAILABLE WAS MADE TO ENSURE THE SOFTWARE WAS AVAILABLE FOR INSTALLATION IF REQUIRED ONCE THE COMPUTER WAS CHANGED. ON RETURNING FROM THE HANGAR I WAS NOTIFIED THAT THE SAME ACFT WOULD ALSO HAVE A WX RADAR WRITE-UP. THIS WOULD BE A 'MUST FIX' -- 'ACFT SHALL NOT RE-PART.' AFTER RETURNING TO THE SHOP AND COMPLETING THE COMPUTER ENTRIES FOR THE PART CHANGES; I DISCOVERED THE WRONG PART NUMBER HAD BEEN INSTALLED. I NOTIFIED MAINT CTL IMMEDIATELY AS THE ACFT HAD LEFT THE GATE. CORRECT PART NUMBER COMPUTER WAS INSTALLED AT THE NEXT STATION.

Data retrieved from NASA's ASRS site as of January 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.