Narrative:

On aug/xa/01 the air crew on aircraft were performing their preflight inspection. Upon inspecting, the crew found the #2 engine egt digital indicator blank. The crew contacted maintenance via VHF radio which I responded by asking what the problem was. When I was told what the malfunction was, I proceeded to go to our parts shelf and found a digital egt indicator in stock. I took the part out to the aircraft and proceeded to troubleshoot the malfunction. Upon completion of troubleshooting, I found that the #2 engine egt indicator was at fault. I replaced the indicator with the one from stock, which both indicators look identical except for the different range markings. I performed the operations check which was normal then performed the corrective action in the aircraft logbook which in time shortly after that the aircraft departed the gateway on time. The aircraft flew schedule flts with no discrepancies on the #2 engine egt system until on aug/thu/01. Aircraft was inbound to anc when the flight crew noticed the #2 engine egt indicator had different range markings. The #2 engine egt indicator was a B747-100 indicator (JT90-7A) not a B747-200 indicator (JT9D-7Q). The crew notified maintenance and wrote up the #2 engine egt indicator being a -100 indicator in the aircraft logbook. The mechanic working the aircraft replaced the indicator with the proper indicator and cleared the maintenance discrepancy in the aircraft logbook.

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Original NASA ASRS Text

Title: A B747-200 WAS DISPATCHED AND OPERATED FOR 6 DAYS IN NON COMPLIANCE WITH THE INCORRECT #2 ENG EXHAUST GAS TEMP INDICATOR INSTALLED.

Narrative: ON AUG/XA/01 THE AIR CREW ON ACFT WERE PERFORMING THEIR PREFLT INSPECTION. UPON INSPECTING, THE CREW FOUND THE #2 ENG EGT DIGITAL INDICATOR BLANK. THE CREW CONTACTED MAINT VIA VHF RADIO WHICH I RESPONDED BY ASKING WHAT THE PROB WAS. WHEN I WAS TOLD WHAT THE MALFUNCTION WAS, I PROCEEDED TO GO TO OUR PARTS SHELF AND FOUND A DIGITAL EGT INDICATOR IN STOCK. I TOOK THE PART OUT TO THE ACFT AND PROCEEDED TO TROUBLESHOOT THE MALFUNCTION. UPON COMPLETION OF TROUBLESHOOTING, I FOUND THAT THE #2 ENG EGT INDICATOR WAS AT FAULT. I REPLACED THE INDICATOR WITH THE ONE FROM STOCK, WHICH BOTH INDICATORS LOOK IDENTICAL EXCEPT FOR THE DIFFERENT RANGE MARKINGS. I PERFORMED THE OPS CHK WHICH WAS NORMAL THEN PERFORMED THE CORRECTIVE ACTION IN THE ACFT LOGBOOK WHICH IN TIME SHORTLY AFTER THAT THE ACFT DEPARTED THE GATEWAY ON TIME. THE ACFT FLEW SCHEDULE FLTS WITH NO DISCREPANCIES ON THE #2 ENG EGT SYS UNTIL ON AUG/THU/01. ACFT WAS INBOUND TO ANC WHEN THE FLC NOTICED THE #2 ENG EGT INDICATOR HAD DIFFERENT RANGE MARKINGS. THE #2 ENG EGT INDICATOR WAS A B747-100 INDICATOR (JT90-7A) NOT A B747-200 INDICATOR (JT9D-7Q). THE CREW NOTIFIED MAINT AND WROTE UP THE #2 ENG EGT INDICATOR BEING A -100 INDICATOR IN THE ACFT LOGBOOK. THE MECH WORKING THE ACFT REPLACED THE INDICATOR WITH THE PROPER INDICATOR AND CLRED THE MAINT DISCREPANCY IN THE ACFT LOGBOOK.

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.