I've recently retired after 46 years as a pilot with 3 airlines. The only thing I miss is seeing my mates for a beer in the evenings. Airlines are run by bean counters, their job is to keep the show on the road no matter what, which brings me to an incident that occurred a few years ago in North America.
On fuelling the aircraft, fuel began spilling from the port surge tank. Engineering at main base told the problem was a fuel valve and laid it on very thick that there was nothing wrong with the aircraft and that I should get going. I suspected that there was more to this problem and finally went back to the hotel, very expensive. Engineering were furious and told me so, there were veiled threats. On reporting for duty the next day I was told by the local engineer that he had found a serious problem with the densitometers in No. 2 main tank and that the flight deck fuel gauge was in error by 5000kgs. This defect had been undetected for months since an overhaul in China. Despite requesting an explanation from those in head office, none was forthcoming.