Technicians and Maintenance Controller reported applying an incorrect MEL to a B737 MAX with an Engine Anti Ice problem. The aircraft departed before the error was discovered.
Synopsis
Technicians and Maintenance Controller reported applying an incorrect MEL to a B737 MAX with an Engine Anti Ice problem. The aircraft departed before the error was discovered.
Narrative
I was assigned to man the gates for late night aircraft turns for the evening. Aircraft X arrived approximately XB45 and was scheduled to depart to ZZZ at XC45. Aircraft X arrived with 2 inbound write ups. Logbook Referral Sheet # XXXXXXX for intermittent Right Engine Anti Ice Light during climbout; and Logbook Referral Sheet # XXXXXXY for MAINT Light related to Engine Anti Ice issue. Maintenance Control was called for deferral of Engine Cowl Anti Ice. MEL 30-XX-X was applied in conjunction with MEL 36-XX-Y (MEL 30-XX-X states to apply MEL 36-XX-Y). Maintenance Control was in concurrence and agreement with me; and Dispatch was also in agreement for application of MEL 30-XX-X. We then proceeded to start MELs by locking out valves and performing Aircraft Maintenance Manual (AMM) procedures and ran into an issue with MEL 30-XX-X; with the disconnection of all 3 pressure switches. Only 2 existed. Engineering Department reviewed our MELs being applied to Aircraft X; and presumably agreed concurrence with MEL and issue found; then proceeded to create Engineering Authorization for acknowledgement of our issue of 2 pressure switches vs what MEL states for 3 pressure switches. All final checks were accomplished; logbook was signed and approved for deferral; then Aircraft X left the gate after a 2 hour and 30-minute delay heading to ZZZ1. The next day; I was notified by Maintenance Control Technician Person A who worked with me the night before; stating that we applied the wrong MEL to Aircraft X; and the Aircraft should have been grounded due to the issue it had.The event occurred due to inadequate training and knowledge of the new 737 MAX changes to its systems. I; the Maintenance Control Department including Crew that night; Dispatch Department; and possibly the Engineering Department had no idea that the wrong MEL was applied; while ALL of us were in agreement about correct MEL placement to Aircraft X. The MAX has 2 new lights above the ENG ANTI-ICE selector switches that are named ENGINE ANTI-ICE. I have personally performed Anti-Ice MELs before; but I did not know that those 2 new lights were added as a change to the MAX. The right-hand ENGINE ANTI-ICE light was the discrepant issue; not the COWL ANTI-ICE which was the deferral used. Reasons that the event occurred are due to the fact of inadequate knowledge of the 737 MAX. All Technicians qualified in ZZZ received a very brief; X-hour classroom training. The training we received in its entirety was not sufficient enough to possibly save an issue from happening like this again. The issue was found by 1 Technician working that night later in the evening and was the only Technician familiar with this issue due to a problem he has dealing with an ENGINE ANTI-ICE light before. Pressure was applied to me with another broken Aircraft; Aircraft X on a turn; a Period service check I still had to perform that left at XI00; after finishing turns at XE00 and also constant phone calls about the status of the aircraft; pressure from Management to hurry; and Crew time-out being almost used to cancel flight.TRAINING. Training on the MAX is crunched down into a X-hour classroom; which is not efficient enough to learn an entire new airframe and new power plant. All qualified technicians on the MAX now bear the responsibility to know all systems; though our other aircraft training was a Y-week course. This shortening of course time will only lead to lack of knowledge and complacency. This tactic is very dangerous. Insufficient training to either Flight or Maintenance personnel is a human factor we can all avoid if we were taught with more specifics on aircraft. I cannot recall learning about this specific change to the ANTI-ICE system on a 737 MAX in our X-hour course. It makes you wonder what else the company missed to put in their official MAX Maintenance training program. The company needs to withhold the responsibility for inadequate training and must not hold the people performing the work be held accountable for actions they simply just don't know.
Second reporter narrative
Received a call from ZZZ about Aircraft X. The aircraft had a write up for INTERMITTENT RIGHT ENGINE ANTI-ICE LIGHT DURING CLIMB OUT. This is a common issue on the 737 NG and points to Cowl Anti Ice. When discussing MEL with Maintenance; our thoughts went straight to a Cowl Anti Ice problem. After issues with applying MEL 30-XX-X needed Engineering Authorization and 35-XX-Y; we deferred the items and closed the aircraft out. I was approached shortly after by a coworker that alerted me that we may not have applied the MEL properly. We mistakenly missed that the MAX has an extra valve for Engine Anti Ice (Core Booster). I contacted the Dispatcher; and he advised me that the aircraft had just taken off a minute before. He said he would contact his Chief Dispatcher to discuss options.Complacency with a similar issue. Training and awareness.The software program is where we confirmed there was an issue. I will try to be more aware when evaluating issues with the MAX. Training and awareness. Talking to a few fellow technicians and mechanics; training was anywhere from a few hours to X days for the Differences class.
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Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.