Originally Posted by Beer Baron
A considered crew puts on extra gas, accepts the payload penalty, wears the added fuel burn but then cops a delay as another operator jumps the queue as they didn't bother to put the fuel on.
Ryanair have been accused of doing exactly that in the past: See the 2012 Valencia incident:
Ryanair ordered to 'review' fuel policy after making THREE emergency landings because planes almost ran out | Daily Mail Online
Ryanair investigation prompts call for new fuel guidelines
Although the Madrid-based Civil Aviation Accident and Incident Investigation Commission (CIAIAC) confirmed that Ryanair had not breached air safety regulations, it noted that the airline operates flights with minimal fuel to save money, which “leaves none for contingencies”, the industry magazine Travel Weekly reports.
It added that Ryanair’s policy was putting it at an economic advantage, which was encouraging other airlines to follow suit – a situation which might result in airports facing “simultaneous emergency declarations for lack of fuel”.