A319
Maintenance Powerplant; Maintenance Airframe
Communication Breakdown; Confusion; Situational Awareness
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action; General Flight Cancelled / Delayed
Human Factors; MEL; Manuals; Procedure; Company Policy; Aircraft; Chart Or Publication
Mechanic Y created a Maintenance write-up item in the logbook [requiring a verification Check for condition prior to flight]; to defer the #2 Engine abradable liner that had damage located from the two to three o'clock position [on the Fan Case inner surface].  After initial review of the deferral; I felt that it lacked detailed information concerning the damage specified. I then called Maintenance and spoke with Mechanic Y concerning the lack of information on the deferral. He informed me that he had been in conversation with Engineer X and then explained to me the extent of the damaged area (crater damage 13.5' x 3.5') inches. I was initially concerned that the damaged area was not within limits; but during our conversation he reiterated the fact that Engineer X informed him the damage fell within the 'Over Serviceable-Limit Extensions' In Accordance With (IAW) the Aircraft Maintenance Manual (AMM) 72-00-00-200 due to the fact that the damaged areas length was [less than] <5 x it's width.  Mechanic Y at that point updated the deferral with a detailed description of the damage and I reviewed the deferral using the 'Over Serviceable-Limit Extension' reference with the understanding that the 'Over Serviceable-Limit Extension' was concerned more with the size of the area (length <5x width) than the overall length and width; due to input received from Engineer X. But within that task was a statement 'If the damage is within the maximum serviceable limit IAW AMM 72-23-00-210 a width greater than 2.5' inches is considered the maximum width allowed and under the remarks area refers back to the 'Over Serviceable-Limit Extension'. It was found that the 'Over Serviceable Limit Extension' IAW AMM 72-00-00-200 was not an appropriate deferral due to the fact that the damaged area was greater than 2.5' inches in width.I was informed by Maintenance Control Management. The AMM limits were misinterpreted due to differing opinions on how the information was evaluated. The aircraft was taken out of service and #2 Engine was removed and replaced. Be more vigilant in reading and interpreting the Aircrafts Maintenance Manuals (AMM) without the influence of others.
The following is an order of events surrounding the finding; researching; and determining course of action of damage found to the Fan Case abradable lining within the Right Engine (#2) on an A319 aircraft. While performing a walk around. Notified; upon discovery; Lead Mechanic X and let him know that I would 'need to tap (his) knowledge' for finding the damage limits for this area. [Note: Lead Mechanic X has a more broad range of knowledge in this regard due to his extended time working in the C-Check Hangar. It was my intent to utilize his knowledge for an accurate assessment of the damage. Returned to aircraft to begin taking measurements and drawing of damaged area. Returned inside to find Lead Mechanic X researching the manuals to assist me in this area. While Lead Mechanic X was researching; I too began to research separately in other manuals. Mechanic Z; assigned to a different aircraft; entered the room. At this point I questioned Mechanic Z if he knew where I could find the damage limits for the abradable lining in the engine inlet. [Note: Mechanic Z also had a broad range of knowledge regarding this due to his extended time working in C-Checks as well]. Mechanic X found the reference I would need to continue with damage assessment. Mechanic Z requested that we go to the area in question and take some pictures to forward to Engineering. Returned inside; informed Lead Mechanic X that I have a reference and that Mechanic Z had taken photos of the damage. Asked Lead Mechanic X who we should contact. It was decided to contact Engineering and forward the pictures to them. Contacted Engineering Department. Spoke with Engineer X [in ZZZ1]. Explained the situation and asked if he would like for me to forward to him the pictures we had. He agreed. With pictures forwarded and received; it was determined that we should follow the Aircraft Maintenance Manual (AMM) reference Chapter 72-23-00-210; Step 4; Paragraph A: 'Crater' parameters. Upon reading this (while on the phone with Engineer X) and seeing that we didn't seem to meet the 'Maximum Serviceable Limits'; I expressed my concern of the factors that kept us from falling within theses guidelines; and twice mentioned [that] the parent [Base] metal that was showing. Engineer X mentioned that if we fall outside of those limits; we can then proceed to the next section which covers 'defect above those limits'; AMM 72-00-00-200. [While] off of the phone and reading; I came to the conclusion that we seem to still fall outside of the limits. I was concerned with the parent [Base] metal showing [in the Fan Case]`and the 'maximum axial width'. I brought my concerns back to Lead Mechanic X. Lead Mechanic X read the AMM information then asked if I could show him the damage; which I did. Upon returning back from the aircraft; Lead Mechanic X read the parameters again and contacted Engineering expressing his concern on my behalf. Engineering seemed confident that we would fall into the 'defect above those limits' and said that they would forward this information to us. Lead Mechanic X received the information from Engineering and printed it for me to read. After reading the information; I was still not satisfied that we were within serviceable tolerances and contacted Engineer X again; to have him 'walk-me-through' where he was getting his information from. Engineer X 'walked-me-through' the steps he followed; and upon reaching that point; I concurred and asked if I should initiate a Repetitive Check Deferral? I was instructed to do so for the '50 cycles or 125 hours' [deferral] as prescribed by AMM 72-00-00-200. I shared with him that it seemed as though the application [installation] of the Abradable Liner was not done correctly at the time of installation; in my opinion. [Later]; off of the phone; I asked Lead Mechanic X if I would also need to create a damage history file to go with the Repetitive Deferral?. Neither of us could say decisively; so I contacted Maintenance Control for their opinion/thoughts. Talked with Mr.Y in Maintenance Control and explained the entire situation to this point and asked if I needed to create a damage history file to go with the Repetitive Check Deferral; or apply the deferral [only]? After being placed on hold for about 15-20 seconds; he came back and said that after conferring with another Controller; only the Repetitive Check Deferral would be necessary because; 'it's not a dent or scratch that the flight crew will see. It's in the engine.' Looking for confirmation; I asked; 'So; I only have to create a Repetitive Check Deferral and NOT a damage history file?' His answer was 'Yes'. Using a Maintenance Reporting Form; I created a Repetitive Check Deferral relating to the damage found with the time limits established in the AMM (as stated above) and entered the [information] into the Sceptre Maintenance computer system. I expressed my concern that we would probably hear back from someone telling me to make a damage history file. Approximately 10-minutes later; Mr. X; from Maintenance Control Technical (Tech) support; called and requested more information regarding the damage. Sharing information to be certain to get ALL the wording in that he was looking for; he seemed to think we were out of tolerance based on my references. I shared my concern; but informed him that I had been in discussion with Engineer X. Technical support Mr. X seemed pleased with that discussion and just needed for me to update the item with measurements; which I did immediately upon hanging up. I was notified [again] by Maintenance Controller Tech support desk Mr.X; on my first night back to work this week. Mr.X informed me that he had been made aware of an event surrounding an A319 aircraft by his Supervisor and he; Mr.X; contacted me to inform me as well. I was made aware that the damage to the Abradable lining on Engine #2 was later determined a few days later to be out-of-limits and should have been found to be such at the time of discovery of said damage. It seemed that the initial conversation with Engineering focused on the 'parent metal' showing and the 'length <5'inches x width' rather than the more detrimental measurements themselves; whereby the maximum axial width had been exceeded. Repeated voiced concerns of possibly being out-of-limits; based on measurements at hand; seemed only to return focus by Engineering to the length/width feature. Although Engineering had photos and a detailed sketch; this didn't seem to draw focus to the limits that were; a few days later; deemed to be out-of-limits by that same department. Similar information relayed to Engineering a few days later resulted in a different outcome. Difference in outcome may be due to aircraft having flown numerous cycles and damage conditions may have propagated since original find. A few days later; during a walk-around; during normal operation day; a Pilot noticed the damage to the Engine #2 Abradable lining and notified Maintenance. Maintenance took pictures and measurements and forwarded those to Maintenance Control and Engineering. Soon thereafter; Engineering determined that the damage was beyond those described by the AMM. Aircraft was taken out of service and ferried for an engine change. Suggest [that] possibly communicating this concern to more than just an Engineer...possibly involvement of a Supervisor to assist in discussions with Engineering. Or involvement of the Duty Manager to assist as well. At this station; we also have a team of inspectors on duty during Night shift. Possible involvement of this [Inspection] Department could have helped as well.
A Maintenance Controller and Line Mechanic describe the order of finding; researching and decision making used to defer a damaged abradable liner that was 'out of limits' on the #2 engine fan case inlet on an A319 aircraft.