Narrative:

On the evening of jun/mon-tue/05; I was tasked; along with mr X; to perform a maintenance check. Since there was only the 2 of us doing this check instead of a full check crew; we decided to do the check outside at the gate where it came in to save the time that towing would take from us towing it to the hangar and then back in the morning. We split the task cards between us; with mr X having all the interior cards; and myself having the exterior cards. After completing all of the task cards; the only write-up I had was the 'inboard side of #2 nose cowl exterior has 15 loose and pulled through rivets.' I reported the discrepancy to the lead; mr Y. He then ordered the nose cowl from stores. I pulled up the maintenance manual reference and went back to the aircraft and started to strip the cowling from the engine. At approximately XA00 I was down to just the inboard upper cowl; and the nose cowl. Mr X had finished the interior and together we finished stripping these 2 cowls from the engine; leaving the nose cowl attached with 1 bolt on each side. While we were doing this; stores pulled up and delivered the crated nose cowl. We then looked at the inventory tag on the crate which stated that it contained 'air carrier #123; tt#X; serial number X nomenclature cowl r-hand nose.' after uncrating the cowl; we found that it had an anti-FOD boom installed on it. Aircraft X is not equipped for that system; so we removed the boom and installed the blanking plate. We then used the lid from the crate to set the old nose cowl on when we removed it from the engine. I removed the tracking tag from the new cowl; taking the sticker off and attaching the tag to the old cowl with the tape that was on it. At this point it was approximately XA15; the WX was heavy clouds but no rain; lighting was dim. While doing this; I did not notice that the last digit was a 'B' instead of an 'a' as the crate tag had indicated. We then installed the nose cowl onto the engine. Normally; with just 2 of us doing this it would have typically taken a bit of man handling to get a bolt started; however; on this occasion the cowl lined up perfectly and I was able to start a bolt and loosely tighten it to secure the outboard side. I then moved around to the side that mr X was holding up and started a bolt there on the inboard side and lightly tightened it. We then installed the rest of the bolts and connected the anti-ice ducts loosely. About this time; mr X came out to help. All bolts and the ducts were torqued to specification and then we installed the engine body cowls. The time was now approximately XB20 and we went inside to eat lunch. After lunch; I completed the paperwork and entered it all onto computer. Mr X had gone out and crated up the old cowl while I was doing this. Once the lead completed the package and logbook; I delivered the logbook to the aircraft. Supplemental information from acn 662785: after arrival in ZZZ1; I was advised by a maintenance specialist that the wrong engine cowling nose section (the cowling lip; not the bullet nose) had been installed on the right engine of aircraft X on jun/tue/05. Apparently; a left engine forward cowl had somehow been installed on the right engine. The aircraft flew normally; and was in-rig with the aileron and rudder trims near zero. Engine operation was normal and the engines/throttles seemed in-rig as well. The error as reportedly detected by a review of maintenance records.

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Original NASA ASRS Text

Title: A B737-200 WAS DISPATCHED WITH A L INLET NOSE COWL INSTALLED ON THE R ENG. CAUSED BY SVCABLE PARTS TAG ERROR. ACFT PERFORMANCE.

Narrative: ON THE EVENING OF JUN/MON-TUE/05; I WAS TASKED; ALONG WITH MR X; TO PERFORM A MAINT CHK. SINCE THERE WAS ONLY THE 2 OF US DOING THIS CHK INSTEAD OF A FULL CHK CREW; WE DECIDED TO DO THE CHK OUTSIDE AT THE GATE WHERE IT CAME IN TO SAVE THE TIME THAT TOWING WOULD TAKE FROM US TOWING IT TO THE HANGAR AND THEN BACK IN THE MORNING. WE SPLIT THE TASK CARDS BTWN US; WITH MR X HAVING ALL THE INTERIOR CARDS; AND MYSELF HAVING THE EXTERIOR CARDS. AFTER COMPLETING ALL OF THE TASK CARDS; THE ONLY WRITE-UP I HAD WAS THE 'INBOARD SIDE OF #2 NOSE COWL EXTERIOR HAS 15 LOOSE AND PULLED THROUGH RIVETS.' I RPTED THE DISCREPANCY TO THE LEAD; MR Y. HE THEN ORDERED THE NOSE COWL FROM STORES. I PULLED UP THE MAINT MANUAL REF AND WENT BACK TO THE ACFT AND STARTED TO STRIP THE COWLING FROM THE ENG. AT APPROX XA00 I WAS DOWN TO JUST THE INBOARD UPPER COWL; AND THE NOSE COWL. MR X HAD FINISHED THE INTERIOR AND TOGETHER WE FINISHED STRIPPING THESE 2 COWLS FROM THE ENG; LEAVING THE NOSE COWL ATTACHED WITH 1 BOLT ON EACH SIDE. WHILE WE WERE DOING THIS; STORES PULLED UP AND DELIVERED THE CRATED NOSE COWL. WE THEN LOOKED AT THE INVENTORY TAG ON THE CRATE WHICH STATED THAT IT CONTAINED 'ACR #123; TT#X; SERIAL NUMBER X NOMENCLATURE COWL R-HAND NOSE.' AFTER UNCRATING THE COWL; WE FOUND THAT IT HAD AN ANTI-FOD BOOM INSTALLED ON IT. ACFT X IS NOT EQUIPPED FOR THAT SYS; SO WE REMOVED THE BOOM AND INSTALLED THE BLANKING PLATE. WE THEN USED THE LID FROM THE CRATE TO SET THE OLD NOSE COWL ON WHEN WE REMOVED IT FROM THE ENG. I REMOVED THE TRACKING TAG FROM THE NEW COWL; TAKING THE STICKER OFF AND ATTACHING THE TAG TO THE OLD COWL WITH THE TAPE THAT WAS ON IT. AT THIS POINT IT WAS APPROX XA15; THE WX WAS HVY CLOUDS BUT NO RAIN; LIGHTING WAS DIM. WHILE DOING THIS; I DID NOT NOTICE THAT THE LAST DIGIT WAS A 'B' INSTEAD OF AN 'A' AS THE CRATE TAG HAD INDICATED. WE THEN INSTALLED THE NOSE COWL ONTO THE ENG. NORMALLY; WITH JUST 2 OF US DOING THIS IT WOULD HAVE TYPICALLY TAKEN A BIT OF MAN HANDLING TO GET A BOLT STARTED; HOWEVER; ON THIS OCCASION THE COWL LINED UP PERFECTLY AND I WAS ABLE TO START A BOLT AND LOOSELY TIGHTEN IT TO SECURE THE OUTBOARD SIDE. I THEN MOVED AROUND TO THE SIDE THAT MR X WAS HOLDING UP AND STARTED A BOLT THERE ON THE INBOARD SIDE AND LIGHTLY TIGHTENED IT. WE THEN INSTALLED THE REST OF THE BOLTS AND CONNECTED THE ANTI-ICE DUCTS LOOSELY. ABOUT THIS TIME; MR X CAME OUT TO HELP. ALL BOLTS AND THE DUCTS WERE TORQUED TO SPEC AND THEN WE INSTALLED THE ENG BODY COWLS. THE TIME WAS NOW APPROX XB20 AND WE WENT INSIDE TO EAT LUNCH. AFTER LUNCH; I COMPLETED THE PAPERWORK AND ENTERED IT ALL ONTO COMPUTER. MR X HAD GONE OUT AND CRATED UP THE OLD COWL WHILE I WAS DOING THIS. ONCE THE LEAD COMPLETED THE PACKAGE AND LOGBOOK; I DELIVERED THE LOGBOOK TO THE ACFT. SUPPLEMENTAL INFO FROM ACN 662785: AFTER ARR IN ZZZ1; I WAS ADVISED BY A MAINT SPECIALIST THAT THE WRONG ENG COWLING NOSE SECTION (THE COWLING LIP; NOT THE BULLET NOSE) HAD BEEN INSTALLED ON THE R ENG OF ACFT X ON JUN/TUE/05. APPARENTLY; A L ENG FORWARD COWL HAD SOMEHOW BEEN INSTALLED ON THE R ENG. THE ACFT FLEW NORMALLY; AND WAS IN-RIG WITH THE AILERON AND RUDDER TRIMS NEAR ZERO. ENG OP WAS NORMAL AND THE ENGS/THROTTLES SEEMED IN-RIG AS WELL. THE ERROR AS REPORTEDLY DETECTED BY A REVIEW OF MAINT RECORDS.

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.