Narrative:

During my walk around of aircraft I found FOD on first stage fan blade #14 of number 1 engine. Through a series of events an inadvertent omission of maintenance documentation occurred which resulted in an exceedance of a time limit given for an engine borescope deferral to inspect for further damage. The aircraft arrived at the gate and the discovery of the damage. The turn time was to be within an hour and so there was a lot of activity around the aircraft. I was the only mechanic involved initially until I determined the blade damage to be out of limits requiring repair. At that time I was asked to blend the blade but it was soon discovered that we had no one on shift that was fluorescent dye penetrate qualified. My supervisor; my lead and maintenance engineering were all involved; each offering suggestions etc. On the situation. Right in the middle of all this we were required to tow the aircraft off the gate to the hangar. The decision was made by management to replace the effected blade and the opposite blade as a pair; thus negating the need for the fluorescent dye penetrate inspection. The blades were changed by myself and [another mechanic]; after maintenance we ran the engine to verify if normal vibration levels were achieved. There were no discrepancies so we closed the log page. The problem is that the conditional inspection I performed was not documented and the engine borescope deferral was not entered in the log book as a deferral. The aircraft exceeded the 10 cycles/ 15 flight hours that would have applied had I initiated the deferral. I have learned that the borescope was performed due to a technical request that powerplant engineering initiated. I was happy to hear there were no discrepancies noted.I met aircraft and started my walk around and discovered a nick in first stage fan blade #14 of #1 engine. I immediately accomplished a general visual inspection (gvi) of the air inlet intake; blades; booster; igv's and CSD oil cooler; as well as the blocker doors and exhaust sections. I determined that no other damage was present and that nothing had gone into the booster. I radioed my maintenance lead and relayed the information. I was immediately asked how long to fix the problem. At this point I knew I must measure the damage and consult [maintenance manual] for continued service allowable damage criteria or begin a repair if possible. The stress was starting to build and due to the fact that our shift is generally shorthanded when it comes to anything out of the normal (like aircraft with more in depth discrepancies). I was given one hour to advise the lead of my intentions. I immediately tried to locate the fan blade template to at least get an approximate measure of the damage. Also; the damage was inside of the mid-span shroud which I knew to be fairly restrictive from past events I had been involved with. I looked in the [maintenance manual] hoping to identify the area on the blade; I had difficulty moving forward; so I called engineering and spoke to [another individual]; he was helpful but so far I hadn't thought about writing the damage criteria down. I knew the 'advise time' was coming (I could feel the stress building) I was told by another mechanic that there was a FOD conditional inspection that I should look for because after blending (and due to the area of damage) there would be a borescope needed which may be deferrable. During my search for references it was difficult to easily follow the path to the table which eventually helped; located in [the maintenance manual]; 'bird strike or FOD with normal parameters'. Also confusing was in [the manual] 'bird strike conditional inspection...' there is no mention of FOD; it is in the body of the document with a hyperlink 'bird strike/FOD with normal engine parameters' it is important to note that I talked with the crew about the blade when I first discovered the damage and they related that there was no abnormal engine parameters noted during flight. As the aircraft was in the hangar; we started the process of the blade pair replacement. The job went well; however; I still had not documented the conditional inspection in the logbook; even though I accomplished that inspection. The table [in the maintenance manual] I found to be confusing; so; knowing that my gvi had passed I was satisfied that no further action was required and also [another mechanic] concurred with this. We closed the log page and released the aircraft to service.we realized that [the] aircraft was in [a] hangar on a maintenance hold for some unrelated repairs. I immediately called powerplant engineering and talked about what happened. He initiated an aircraft on ground (aog) technical request to have the borescope accomplished before further flight.first I must say that I was a victim of several of the 'dirty dozen'; the stress level at the time of the incident was already high due to shift change (days to swings) we have several inbound flights at this time; also aircraft towing demands put a strain on our short staffed swing shift; timing constraints for aircraft turn times are constantly on my mind; having tooling at the hangar instead of the line makes it difficult..3 to 5 min. Drive each way; having to orchestrate advise times; interact with maintenance control; operations and ground crew all takes a toll on us. In closing; slowing down and following the steps... Discover then document; stay focused and if interrupted start over if you have to; try to not worry about when the aircraft is scheduled to depart; ask for help including technical services; engineering; co-workers etc. Having a clear path in the various chapters of the manuals... Something easy to follow would be nice. Perhaps a computer based training on negotiating the manuals would help.

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Original NASA ASRS Text

Title: Maintenance Technician reported that after making a repair on a fan blade he neglected to document the inspection performed and the required engine borescope was not entered in the log book.

Narrative: During my walk around of aircraft I found FOD on first stage fan blade #14 of number 1 engine. Through a series of events an inadvertent omission of maintenance documentation occurred which resulted in an exceedance of a time limit given for an engine borescope deferral to inspect for further damage. The aircraft arrived at the gate and the discovery of the damage. The turn time was to be within an hour and so there was a lot of activity around the aircraft. I was the only mechanic involved initially until I determined the blade damage to be out of limits requiring repair. At that time I was asked to blend the blade but it was soon discovered that we had no one on shift that was fluorescent dye penetrate qualified. My supervisor; my lead and maintenance engineering were all involved; each offering suggestions etc. on the situation. Right in the middle of all this we were required to tow the aircraft off the gate to the hangar. The decision was made by management to replace the effected blade and the opposite blade as a pair; thus negating the need for the fluorescent dye penetrate inspection. The blades were changed by myself and [another mechanic]; after maintenance we ran the engine to verify if normal vibration levels were achieved. There were no discrepancies so we closed the log page. The problem is that the conditional inspection I performed was not documented and the engine borescope deferral was not entered in the log book as a deferral. The aircraft exceeded the 10 cycles/ 15 flight hours that would have applied had I initiated the deferral. I have learned that the borescope was performed due to a technical request that powerplant engineering initiated. I was happy to hear there were no discrepancies noted.I met aircraft and started my walk around and discovered a nick in first stage fan blade #14 of #1 engine. I immediately accomplished a General Visual Inspection (GVI) of the air inlet intake; blades; booster; IGV's and CSD oil cooler; as well as the blocker doors and exhaust sections. I determined that no other damage was present and that nothing had gone into the booster. I radioed my maintenance Lead and relayed the information. I was immediately asked how long to fix the problem. At this point I knew I must measure the damage and consult [maintenance manual] for continued service allowable damage criteria or begin a repair if possible. The stress was starting to build and due to the fact that our shift is generally shorthanded when it comes to anything out of the normal (like aircraft with more in depth discrepancies). I was given one hour to advise the lead of my intentions. I immediately tried to locate the fan blade template to at least get an approximate measure of the damage. Also; the damage was inside of the mid-span shroud which I knew to be fairly restrictive from past events I had been involved with. I looked in the [Maintenance manual] hoping to identify the area on the blade; I had difficulty moving forward; so I called engineering and spoke to [another individual]; he was helpful but so far I hadn't thought about writing the damage criteria down. I knew the 'advise time' was coming (I could feel the stress building) I was told by another mechanic that there was a FOD conditional inspection that I should look for because after blending (and due to the area of damage) there would be a borescope needed which may be deferrable. During my search for references it was difficult to easily follow the path to the table which eventually helped; located in [the maintenance manual]; 'Bird strike or FOD with normal parameters'. Also confusing was in [the manual] 'Bird Strike conditional inspection...' there is no mention of FOD; it is in the body of the document with a hyperlink 'Bird strike/FOD with normal engine parameters' It is important to note that I talked with the crew about the blade when I first discovered the damage and they related that there was no abnormal engine parameters noted during flight. As the aircraft was in the hangar; we started the process of the blade pair replacement. The job went well; however; I still had not documented the conditional inspection in the logbook; even though I accomplished that inspection. The table [in the maintenance manual] I found to be confusing; so; knowing that my GVI had passed I was satisfied that no further action was required and also [another mechanic] concurred with this. We closed the log page and released the Aircraft to service.We realized that [the] aircraft was in [a] hangar on a maintenance hold for some unrelated repairs. I immediately called Powerplant Engineering and talked about what happened. He initiated an Aircraft on Ground (AOG) technical request to have the borescope accomplished before further flight.First I must say that I was a victim of several of the 'Dirty Dozen'; the stress level at the time of the incident was already high due to shift change (days to swings) we have several inbound flights at this time; also aircraft towing demands put a strain on our short staffed swing shift; timing constraints for aircraft turn times are constantly on my mind; having tooling at the hangar instead of the line makes it difficult..3 to 5 min. drive each way; having to orchestrate advise times; interact with maintenance control; operations and ground crew all takes a toll on us. In closing; slowing down and following the steps... discover then document; stay focused and if interrupted start over if you have to; try to not worry about when the aircraft is scheduled to depart; ask for help including technical services; engineering; co-workers etc. Having a clear path in the various chapters of the manuals... something easy to follow would be nice. Perhaps a computer based training on negotiating the manuals would help.

Data retrieved from NASA's ASRS site 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.