Weight & Balance
I spent quite a few years doing manual loadsheets in the days before computers came in. Many days our Luton Airport office was stacked high with partly completed loadsheets when Heathrow divertions came in and we were waiting for the actual load details to be advised for their onward trip. I then moved on within aviation but later was back doing manual loadsheets for domestic airlines in Australia. Computers then came in and almost anyone could then do a loadsheet.