Date: 201907
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Aircraft: A320
Operator: Air Carrier
Operating under: Part 121
Mission: Passenger
Flight phase: Parked
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Human factors: Troubleshooting; Training / Qualification
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: Pre-flight
Result: General Maintenance Action
Contributing factors: Human Factors; MEL; Company Policy
Primary problem: Human Factors

Narrative: I sent an ASAP (Aviation Safety Action Program) report that included an issue with a  ZZZ Contract Maintenance mechanic that could not tell an inlet/extract valve open or closed in the Pressurization System Display while working on an MEL. I explained clearly to all of you at the ASAP committee that this mechanic was a serious threat to our operation.  Your response was simply that [Maintenance Control] will be investigating... end of story.  Well... whatever was done or not done; we still have this very serious issue.  First; I do not want to make excuses and I accept responsibility for failing to do my job as the last line of defense in our safety culture and process; yes something fell through the cracks; and I'm very upset that I didn't catch it.  However; I did warn you that having pilots babysit this mechanic's work will one day fail and create problems.  I wonder how many other pilots have had issues with him; how many even knew they had issues; and how many mistakes have been made in total.  This is serious guys.Arrived at report time/on time at the gate in ZZZ for my flight and was told by the gate agents that our airplane was still at the 'A' gates because of the international arrival and that Maintenance was working on the airplane.  So about 40 minutes later; the airplane arrives and the mechanic; who taxied the airplane to our gate; remained in the airplane with the cabin doors closed; this while I; my First Officer and flight attendants waited in the hot jetway.  I could see the mechanic working in the cockpit with buttons and switches while on the telephone; I suspect talking to [Maintenance Control].  The mechanic finally opens the door after 10 minutes or so. We come in; he still has some work to do he says; and that delaying boarding was not necessary.  So he finishes up and leaves; new MEL in place and all signed off.  At first glance it all looks good to me; but of course; I still have to check these MELs dealing with issues with the fuel transfer valves.  The 2 original MELs in the release were XX-XX-30AB-interior trim and XX-XY-01E-ROUTER TANK RH TRNSFR VLV OPEN.  The new MEL was XX-XZ-01D for transfer valve CLOSED (ARTR 1.) So I read through MEL XX-XZ-01D and it stated that the transfer valves should show 'open' and ours were 'closed.'  This mechanic spent all that time working on this MEL leaving us in the WRONG transfer valve configuration! So I immediately called [Maintenance Control] and asked them about the discrepancy. They instructed me to reset a couple of CBs; but that didn't do the trick.  The [Maintenance Control] mechanic kept brainstorming this and figured; 'Looks like this was MEL'd wrong; it should be for while the transfer valves are closed; we'll send a mechanic out.'; this ladies & gentleman was the seed that led to my confusion for the remainder of the process.  They send this same mechanic that brought the airplane in and left us in the wrong transfer valve configuration; and the same one I had issues with on [a few months back].  This mechanic was lost; he could not tell how an opened or closed transfer valve looked like in the system display.  I had to grab my iPad; and show him the diagrams in the MEL book; on how to interpret the display; he was clueless.  He had performed all these MELs with no idea on how transfer valves positions are displayed and set them wrong; very concerning.  So now that I've given him my free 1 minute lesson on transfer valves displays he proceeds to change the MEL.  New ARTR 2; new MEL XX-XA-01H to replace XX-XY-01E.  Somehow; somewhere in my brain (the previously mentioned planted seed) I was under the impression that we were going to be dispatched with the transfer valves closed (that we were changing the MEL in alignment with our current condition; I thought.) I felt glad 'I caught it' and that now this condition is been taken care of.  The mechanic checks his work; sends a picture of the logbook page to [Maintenance Control]; and all is good!Here we go!  Needed to update our release time since it was closing-in to an hour delay; so we received ARTR 3 for that.  We were dispatched with 6;400 over our brake release fuel; so the issue of the external tank fuel total of 3;000 did not flag as a big concern in regards to meeting our fuel requirements since ZZZ was not under any delays.  This extra fuel condition is what I would expect if the valves were to remain closed as they were.  This 'coincidental' extra fuel was really our 'saving grace.'  Through the flight and while in cruise I checked on the MELs placarding and noticed the  placarding were not displaying any 'note;' just the MEL number.  So I changed the placards to conform [to] the MELs. No concerns; since it indicated a condition after the refueling process and not 'Before Flight.'We had a mechanic meet us for these MEL's FRs on our following (return) flight to  ZZZ; and he set us up in just 5 minutes.  Not only were the procedures carried quickly and efficiently; but this mechanic performed the *correct* procedure in stark contrast with the mechanic in  ZZZ that set us up for failure: it was at this point I realized the transfer valves were to remain open for flight.  With this finding; I wanted confirmation and clarification from [Maintenance Control]; so I explained to them that we ended up flying the previous leg with the transfer valves closed and also explained maintenance's confusion with transfer valve MELs in  ZZZ before departure.  I also mentioned that I would be submitting an ASAP.  Although I (shamefully) overlooked the directions on this MELs; I believe these MELs could be written with more clarity.  The condition of 'valves closed' (when they are normally closed at the gate) present a challenging condition first; because it is a 'normal' condition at the gate and second; because there are no ECAMs associated with it.  The 'REMARKS OR EXCEPTIONS' column instructions should be titled 'TRANSFER VALVES NEED TO BE OPEN FOR FLIGHT' for these MELs followed by the current text. For placarding as well; on the 401VU the term 'Before Flight' or 'For Flight' is more effective than 'after fueling.'  'After fueling' implies a procedural step more than a final/dispatch condition.  While talking to [Maintenance Control] after our first leg; the mechanic stated; 'Well; we don't write the MELs; Airbus does!'  So these changes would definitely take time and effort; a lot of red-tape; a big mountain to climb.  Is it worth it? You decide.  For the sake of safety? I think it is.In conclusion; this has been the perfect storm; the poor MEL guidance; the confused and incompetent mechanic; a flawed verification system from [Maintenance Control] (when just pictures of logbook pages are not enough) and a Captain and First Officer that had all of this fall through the cracks after initially finding an issue with an MEL and calling [Maintenance Control]; and [Maintenance Control] sending mechanics to rectify the issue; then the rectification process setting us for failure AGAIN!  If we want a smooth and safe operation we really need to correct these flaws.  Although this issue also falls under my responsibility; poor support is not normal and should not be welcomed/tolerated.  The same with paranoia; it is not normal for flight crews to feel paranoid after every maintenance action; vigilant yes; but paranoid not.




Synopsis: Flight crew reports discrepancies on MEL Deferral paperwork and substandard work performed by Maintenance.