Narrative:

Dispatch called approximately 30 mins prior to aircraft landing and said the crew had sent an ACARS saying they had #1 engine overtemp of 940 degrees C for 4 seconds. After aircraft arrived; we talked about if this was going to be 4 seconds or 24 seconds; because light (red light on egt indicator) comes on after 20 seconds if egt is between 930-940 or it comes on instantly at 940 and above. This is important because the item can be signed off if time between 930-940 was only 4 seconds but if it stayed in that band for 20 seconds then an additional 4 seconds; it would be an area 'a' inspection requirement maintenance action. I gave mr X the amm reference so he could look at it. A few mins later; I talked to this captain so I could fill out the egt exceedance form. We talked about the 20 second delay and I said temperature was 940 degrees. Captain said it was only in overtemp area for 4 seconds. At the end of conversation; captain said 'well; overtemp was actually 947 degrees.' I said ok and told everyone that aircraft would be staying. I figured the troubleshooting had to be accomplished. He said just make a special inspection per temperature indicating system and let aircraft go on. Then; I'm thinking area 'a;' not knowing I could postpone the special inspection. This happened at shift change and I thought the technician would look at amm to verify. In the end; the information changed at the minute and I didn't verify information with amm. I was thinking area 'a' or it was just a signoff per amm. Right after aircraft left; it was discovered that the overtemp was area 'B' not 'a;' therefore; aircraft needed power assurances run and boroscope. Upon arrival in ZZZ1; power assurance was complied with and boroscope was xferred to maintenance note and complied with that night. Complied with boroscope with no defects noted. It is still temperature indicating system overtemp cause. No faults have been found so far. In the end; the problem came down to thinking the whole time that at the most it was an area 'a.' when the pilot told me that it was 'actually 947' I said aircraft would stay in and looked for a swap. Right after that; mechanic said 'you can defer the area 'a' temperature indicating system until tonight. Just write a special inspection.' I was surprised I could do this not thinking I could. I was still thinking it was an area 'a' for what I remembered looking at in the amm. So I wrote the special inspection and had planning set it up. I never thought I had an area 'B' overtemp. All of this happened right at shift change; so I didn't realize the error had happened until I was told later. The mechanic and oncoming maintenance controller realized this after aircraft had left. Supplemental information from acn 805651: I received notice of an aircraft coming in with #1 engine overtemp. Told the captain there would be a delay to correct the problem. I was told there would be a special inspection written. I complied with what the controller said for the corrective action. Back in the shop; I realized the temperature was in area 'B' not 'a.' he and my supervisor took action to repair the mistake.

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Original NASA ASRS Text

Title: A MAINT CONTROLLER AND MECHANIC REPORT ABOUT THE DISPATCH OF A B737-300 WITH A #1 ENG EGT OVERTEMP WRITE-UP; WITHOUT THE REQUIRED POWER ASSURANCE RUN AND BOROSCOPE REQUIREMENTS BEING ACCOMPLISHED.

Narrative: DISPATCH CALLED APPROX 30 MINS PRIOR TO ACFT LNDG AND SAID THE CREW HAD SENT AN ACARS SAYING THEY HAD #1 ENG OVERTEMP OF 940 DEGS C FOR 4 SECONDS. AFTER ACFT ARRIVED; WE TALKED ABOUT IF THIS WAS GOING TO BE 4 SECONDS OR 24 SECONDS; BECAUSE LIGHT (RED LIGHT ON EGT INDICATOR) COMES ON AFTER 20 SECONDS IF EGT IS BTWN 930-940 OR IT COMES ON INSTANTLY AT 940 AND ABOVE. THIS IS IMPORTANT BECAUSE THE ITEM CAN BE SIGNED OFF IF TIME BTWN 930-940 WAS ONLY 4 SECONDS BUT IF IT STAYED IN THAT BAND FOR 20 SECONDS THEN AN ADDITIONAL 4 SECONDS; IT WOULD BE AN AREA 'A' INSPECTION REQUIREMENT MAINT ACTION. I GAVE MR X THE AMM REF SO HE COULD LOOK AT IT. A FEW MINS LATER; I TALKED TO THIS CAPT SO I COULD FILL OUT THE EGT EXCEEDANCE FORM. WE TALKED ABOUT THE 20 SECOND DELAY AND I SAID TEMP WAS 940 DEGS. CAPT SAID IT WAS ONLY IN OVERTEMP AREA FOR 4 SECONDS. AT THE END OF CONVERSATION; CAPT SAID 'WELL; OVERTEMP WAS ACTUALLY 947 DEGS.' I SAID OK AND TOLD EVERYONE THAT ACFT WOULD BE STAYING. I FIGURED THE TROUBLESHOOTING HAD TO BE ACCOMPLISHED. HE SAID JUST MAKE A SPECIAL INSPECTION PER TEMP INDICATING SYS AND LET ACFT GO ON. THEN; I'M THINKING AREA 'A;' NOT KNOWING I COULD POSTPONE THE SPECIAL INSPECTION. THIS HAPPENED AT SHIFT CHANGE AND I THOUGHT THE TECHNICIAN WOULD LOOK AT AMM TO VERIFY. IN THE END; THE INFO CHANGED AT THE MINUTE AND I DIDN'T VERIFY INFO WITH AMM. I WAS THINKING AREA 'A' OR IT WAS JUST A SIGNOFF PER AMM. RIGHT AFTER ACFT LEFT; IT WAS DISCOVERED THAT THE OVERTEMP WAS AREA 'B' NOT 'A;' THEREFORE; ACFT NEEDED PWR ASSURANCES RUN AND BOROSCOPE. UPON ARR IN ZZZ1; PWR ASSURANCE WAS COMPLIED WITH AND BOROSCOPE WAS XFERRED TO MAINT NOTE AND COMPLIED WITH THAT NIGHT. COMPLIED WITH BOROSCOPE WITH NO DEFECTS NOTED. IT IS STILL TEMP INDICATING SYS OVERTEMP CAUSE. NO FAULTS HAVE BEEN FOUND SO FAR. IN THE END; THE PROB CAME DOWN TO THINKING THE WHOLE TIME THAT AT THE MOST IT WAS AN AREA 'A.' WHEN THE PLT TOLD ME THAT IT WAS 'ACTUALLY 947' I SAID ACFT WOULD STAY IN AND LOOKED FOR A SWAP. RIGHT AFTER THAT; MECH SAID 'YOU CAN DEFER THE AREA 'A' TEMP INDICATING SYS UNTIL TONIGHT. JUST WRITE A SPECIAL INSPECTION.' I WAS SURPRISED I COULD DO THIS NOT THINKING I COULD. I WAS STILL THINKING IT WAS AN AREA 'A' FOR WHAT I REMEMBERED LOOKING AT IN THE AMM. SO I WROTE THE SPECIAL INSPECTION AND HAD PLANNING SET IT UP. I NEVER THOUGHT I HAD AN AREA 'B' OVERTEMP. ALL OF THIS HAPPENED RIGHT AT SHIFT CHANGE; SO I DIDN'T REALIZE THE ERROR HAD HAPPENED UNTIL I WAS TOLD LATER. THE MECH AND ONCOMING MAINT CTLR REALIZED THIS AFTER ACFT HAD LEFT. SUPPLEMENTAL INFO FROM ACN 805651: I RECEIVED NOTICE OF AN ACFT COMING IN WITH #1 ENG OVERTEMP. TOLD THE CAPT THERE WOULD BE A DELAY TO CORRECT THE PROB. I WAS TOLD THERE WOULD BE A SPECIAL INSPECTION WRITTEN. I COMPLIED WITH WHAT THE CTLR SAID FOR THE CORRECTIVE ACTION. BACK IN THE SHOP; I REALIZED THE TEMP WAS IN AREA 'B' NOT 'A.' HE AND MY SUPVR TOOK ACTION TO REPAIR THE MISTAKE.

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.