Some time ago, I worked for a small SE Asian airline (now a whole lot bigger) who operated 10 B707's, two of which they ordered new, and the remaining eight from three different Boeing customers.
Switches/lights here and there, all somewhat different.
However, the AFM/QRH's all came from one source...Boeing.
The instructions from the company were quite clear...please operate in accordance with the therein stated Boeing procedures, thank you very much.
Worked like a charm.
Then, one day I approached the 707 fleet manager and suggested a slight change...a flap 40 landing SCD, under certain circumstances.
Reason, less noise and fuel.
He wanted to know...'Just who operates this way?'
PanAmerican, says I.
After I provided the relevant operating data, a change was made to permit flap 40 landings (ISO flap 50)...all of course SCD.
For this small suggestion, I was awarded one months additional salary, and a nice 'thank you' from management.
At this point I also offered another suggestion.
The company should adopt, as the last item on the before takeoff checklist, a configuration check...
Flaps set correctly.
Speed brake lever checked fully forward.
Trim in the takeoff range.
Compass/RMI heading checked/agreed with the mandated takeoff runway.
This was considered and rejected. Don't know why.
However, shortly thereafter, one of the companies B747's was involved in a wrong runway departure (Melbourne, departure on runway 27 instead of 34), with nearly disastrous results.
Checklist change now accepted.
PanAmerican had several mishaps in the early days of jet transport operations, and learned their lessons well.
However, change came more slowly to other operators.
