The airline's crews are notorious for not entering the correct flight number in the transponder and aircraft fly around for weeks showing the same flight number on every flight.
Absolute Rubbish. You are confusing the 'squawk' entered into the Transponder and the Flight Number which is entered into the Flight Data Recorder.
1 -The 'Squawk': According to Aer Arann SOP's this is part of a read and respond (ie Captain and First Officer both check) checklist during the Before Take-Off Checklist. As any pilot (from any Airline) will tell you, flying around with the wrong transponder code will instantly be challenged by ATC.
2 - The Flight Number: Again. according to our SOP's this is enterd during the Final Cockpit Preparation Checklist, it is also a read and do checklist.
I have never heard of both pilots missing both checklists all day (up to 6 sectors), and then another pair of pilots missing the same points on the same checklist the next day, "fly around for weeks.........". Nonsense.
With respect, might I suggest you consider the validity of your comments before posting them.