Gorilla, Mighty Gem,
Not only are there certification differences based on where the aircraft is registered, there are also differences based on different airlines desired SCN's. For example, under the FAA system an airline may have a 10 kt tailwind limit, or they may decided to PURCHASE the option to increase this to 15 kts.
This can also apply to takeoff thrust, 5 minutes is the norm, but for an additional fee you can get 10 minutes.
===========
I dont know if this applies to Spanair or the MD80, but before anyone decides to blame the pilot for busting limits, i think that you better have a look at his AFM.
Mutt.