So….. let's take GDFO as an example….went for a big maintenance job in Dublin not too long ago, had problems since it came back into service and now still sat doing nothing in the hangar.Depends on what you mean as just missing a lifejacket renders an aircraft tech along with many other minor things.
These big services (as I call them) are just like old cars….engines are fine, brake pads are fine but look deeper into older compressors, pipes and the amount other things on an aircraft which as so complex. Doubt they are short of lifejackets