Narrative:

On the evening of 05/wed/02, I was performing my duties as lead ron mechanic when aircraft arrived in ZZZ. During the landing, the flight crew encountered an engine anomaly. When the captain began to stow the thrust reversers during rollout he heard a single pop emanate with an associated flash from the #2 engine. The flight crew called and requested that aircraft maintenance meet them at gate upon arrival. When I walked into the shop from performing a routine check on an ron aircraft, the lead mechanic on duty for evening shift told me about aircraft coming to the gate with a suspected compressor stall. I told the lead mechanic that if it really did have a compressor stall to call maintenance control, because 'I think it's going to need an engine borescope done.' I resumed my duties and proceeded to set up the work assignments for that evening's maintenance activity. After about 15 mins, the evening shift lead asked me to come out and consult with him and the captain regarding the engine problem. The captain said that even though they heard and had a visual cue of a compressor stall, he saw no indication from either engine that would lead him to believe that a stall had occurred. I agreed with both of them, it was possible they encountered a compressor stall on the #2 engine. It was at this time the evening lead called the controller on duty for that aircraft, and told him that the engine could have experienced a compressor stall. After concluding his conversation with the controller, I asked the evening lead what the maintenance controller wants us to do. The evening lead said the maintenance controller told him to 'call him back in a min -- they're going to swap it out and make it a terminating aircraft.' the engine was run at various power settings and along with making rapid power increases and decreases with no sign of any stall or impending compressor stall. All engine indications were normal and consistent in nature, while all parameters were well within the maintenance manual limits. The high power run was unable to yield any evidence of a compressor stall. I returned to the office and called the controller advising him of our findings. He said that was good, an engine borescope was not required because none of the operational limits were exceeded and the engine operated normally on the engine run. I asked him what was the maintenance manual reference that gave relief for not borescoping the engine. He said 71-00-00-2 and after reviewing the reference, I agreed with him that per section J it seemed like it did not require a borescope. I told him that I would visually check the vfv's and vsv's and verify they were properly rigged. I said since this occurred while coming out of reverse thrust, we would also check the #2 engine reverse thrust reverser system. I told the controller that after XA00 the airport would allow us to make a high speed run on the runway and functional check of the engine again under the parameters in which the anomaly occurred. I called the controller and advised him that we were going out to perform the high speed run on the runway. During the test, we achieved maximum takeoff power and when a proper forward speed was obtained, I retarded the throttle rapidly and went directly into reverse applying a significant amount of reverse thrust. All engine indications were normal and well within operational limits on both of the engines. While accelerating, deploying and stowing the thrust reversers there were no signs of a compressor stall. After returning from the engine run, I advised the controller that everything had checked out on aircraft. Today I learned that aircraft required an engine change on jun/sun/02 at our line station of ZZZ1. After reviewing the boeing maintenance manual, I found the appropriate reference which does call for a borescope inspection per 72-00-00-601. I would like to bring to your attention the lack of a straight forward guide within the boeing maintenance manual. I would hope that there is something that the airline could do to help eliminate this item from being missed again in the near future. I relied on the maintenance controller who I thought had a broader knowledge base than my own. I thought with his access to a broader range of technical pubs he could dictate our path to determining a proper course of action. I feel that if there was better direction, visual cues and guidance within the boeing maintenance manual this mistake would not have been made. My gut instinct told me that the engine required a borescope inspection, but my lack of assertiveness allowed this error to happen. I should have pressed the issue with the controller on duty and researched the boeing maintenance manual deeper. I signed for the aircraft, I take full responsibility for the event.

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Original NASA ASRS Text

Title: A B737 IS RETURNED TO SVC WITHOUT A BORESCOPE BEING PERFORMED AFTER THE #2 ENG HAD SUFFERED A COMPRESSOR STALL DURING THE LNDG ROLLOUT AT ZZZ. ACFT LATER HAD A #2 ENG CHANGE AFTER A FAILURE AT ZZZ2, US.

Narrative: ON THE EVENING OF 05/WED/02, I WAS PERFORMING MY DUTIES AS LEAD RON MECH WHEN ACFT ARRIVED IN ZZZ. DURING THE LNDG, THE FLC ENCOUNTERED AN ENG ANOMALY. WHEN THE CAPT BEGAN TO STOW THE THRUST REVERSERS DURING ROLLOUT HE HEARD A SINGLE POP EMANATE WITH AN ASSOCIATED FLASH FROM THE #2 ENG. THE FLC CALLED AND REQUESTED THAT ACFT MAINT MEET THEM AT GATE UPON ARR. WHEN I WALKED INTO THE SHOP FROM PERFORMING A ROUTINE CHK ON AN RON ACFT, THE LEAD MECH ON DUTY FOR EVENING SHIFT TOLD ME ABOUT ACFT COMING TO THE GATE WITH A SUSPECTED COMPRESSOR STALL. I TOLD THE LEAD MECH THAT IF IT REALLY DID HAVE A COMPRESSOR STALL TO CALL MAINT CTL, BECAUSE 'I THINK IT'S GOING TO NEED AN ENG BORESCOPE DONE.' I RESUMED MY DUTIES AND PROCEEDED TO SET UP THE WORK ASSIGNMENTS FOR THAT EVENING'S MAINT ACTIVITY. AFTER ABOUT 15 MINS, THE EVENING SHIFT LEAD ASKED ME TO COME OUT AND CONSULT WITH HIM AND THE CAPT REGARDING THE ENG PROB. THE CAPT SAID THAT EVEN THOUGH THEY HEARD AND HAD A VISUAL CUE OF A COMPRESSOR STALL, HE SAW NO INDICATION FROM EITHER ENG THAT WOULD LEAD HIM TO BELIEVE THAT A STALL HAD OCCURRED. I AGREED WITH BOTH OF THEM, IT WAS POSSIBLE THEY ENCOUNTERED A COMPRESSOR STALL ON THE #2 ENG. IT WAS AT THIS TIME THE EVENING LEAD CALLED THE CTLR ON DUTY FOR THAT ACFT, AND TOLD HIM THAT THE ENG COULD HAVE EXPERIENCED A COMPRESSOR STALL. AFTER CONCLUDING HIS CONVERSATION WITH THE CTLR, I ASKED THE EVENING LEAD WHAT THE MAINT CTLR WANTS US TO DO. THE EVENING LEAD SAID THE MAINT CTLR TOLD HIM TO 'CALL HIM BACK IN A MIN -- THEY'RE GOING TO SWAP IT OUT AND MAKE IT A TERMINATING ACFT.' THE ENG WAS RUN AT VARIOUS PWR SETTINGS AND ALONG WITH MAKING RAPID PWR INCREASES AND DECREASES WITH NO SIGN OF ANY STALL OR IMPENDING COMPRESSOR STALL. ALL ENG INDICATIONS WERE NORMAL AND CONSISTENT IN NATURE, WHILE ALL PARAMETERS WERE WELL WITHIN THE MAINT MANUAL LIMITS. THE HIGH PWR RUN WAS UNABLE TO YIELD ANY EVIDENCE OF A COMPRESSOR STALL. I RETURNED TO THE OFFICE AND CALLED THE CTLR ADVISING HIM OF OUR FINDINGS. HE SAID THAT WAS GOOD, AN ENG BORESCOPE WAS NOT REQUIRED BECAUSE NONE OF THE OPERATIONAL LIMITS WERE EXCEEDED AND THE ENG OPERATED NORMALLY ON THE ENG RUN. I ASKED HIM WHAT WAS THE MAINT MANUAL REF THAT GAVE RELIEF FOR NOT BORESCOPING THE ENG. HE SAID 71-00-00-2 AND AFTER REVIEWING THE REF, I AGREED WITH HIM THAT PER SECTION J IT SEEMED LIKE IT DID NOT REQUIRE A BORESCOPE. I TOLD HIM THAT I WOULD VISUALLY CHK THE VFV'S AND VSV'S AND VERIFY THEY WERE PROPERLY RIGGED. I SAID SINCE THIS OCCURRED WHILE COMING OUT OF REVERSE THRUST, WE WOULD ALSO CHK THE #2 ENG REVERSE THRUST REVERSER SYS. I TOLD THE CTLR THAT AFTER XA00 THE ARPT WOULD ALLOW US TO MAKE A HIGH SPD RUN ON THE RWY AND FUNCTIONAL CHK OF THE ENG AGAIN UNDER THE PARAMETERS IN WHICH THE ANOMALY OCCURRED. I CALLED THE CTLR AND ADVISED HIM THAT WE WERE GOING OUT TO PERFORM THE HIGH SPD RUN ON THE RWY. DURING THE TEST, WE ACHIEVED MAX TKOF PWR AND WHEN A PROPER FORWARD SPD WAS OBTAINED, I RETARDED THE THROTTLE RAPIDLY AND WENT DIRECTLY INTO REVERSE APPLYING A SIGNIFICANT AMOUNT OF REVERSE THRUST. ALL ENG INDICATIONS WERE NORMAL AND WELL WITHIN OPERATIONAL LIMITS ON BOTH OF THE ENGS. WHILE ACCELERATING, DEPLOYING AND STOWING THE THRUST REVERSERS THERE WERE NO SIGNS OF A COMPRESSOR STALL. AFTER RETURNING FROM THE ENG RUN, I ADVISED THE CTLR THAT EVERYTHING HAD CHKED OUT ON ACFT. TODAY I LEARNED THAT ACFT REQUIRED AN ENG CHANGE ON JUN/SUN/02 AT OUR LINE STATION OF ZZZ1. AFTER REVIEWING THE BOEING MAINT MANUAL, I FOUND THE APPROPRIATE REF WHICH DOES CALL FOR A BORESCOPE INSPECTION PER 72-00-00-601. I WOULD LIKE TO BRING TO YOUR ATTN THE LACK OF A STRAIGHT FORWARD GUIDE WITHIN THE BOEING MAINT MANUAL. I WOULD HOPE THAT THERE IS SOMETHING THAT THE AIRLINE COULD DO TO HELP ELIMINATE THIS ITEM FROM BEING MISSED AGAIN IN THE NEAR FUTURE. I RELIED ON THE MAINT CTLR WHO I THOUGHT HAD A BROADER KNOWLEDGE BASE THAN MY OWN. I THOUGHT WITH HIS ACCESS TO A BROADER RANGE OF TECHNICAL PUBS HE COULD DICTATE OUR PATH TO DETERMINING A PROPER COURSE OF ACTION. I FEEL THAT IF THERE WAS BETTER DIRECTION, VISUAL CUES AND GUIDANCE WITHIN THE BOEING MAINT MANUAL THIS MISTAKE WOULD NOT HAVE BEEN MADE. MY GUT INSTINCT TOLD ME THAT THE ENG REQUIRED A BORESCOPE INSPECTION, BUT MY LACK OF ASSERTIVENESS ALLOWED THIS ERROR TO HAPPEN. I SHOULD HAVE PRESSED THE ISSUE WITH THE CTLR ON DUTY AND RESEARCHED THE BOEING MAINT MANUAL DEEPER. I SIGNED FOR THE ACFT, I TAKE FULL RESPONSIBILITY FOR THE EVENT.

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.