This 100 tonne error is regularly made by aircrew in all sorts of airlines.
Please don't say that. As occasional SLF, I'd like to think that there is some sort of CQI process at work to catch the outlying events and work to eliminate sources of error in the process. Don't get me wrong: I appreciate the piloting skill that manages to get my overweight flight off the runway. I just hope that someone is working to reduce the incidence below what one would define as "regularly".
