So what is the true reason that it will be ensured that the aircraft is never completely full?
Might it just have something to do with S2000 aircraft performance, that PMI is a fair old trek for a S2000, and a less than ideal Oxford runway and the operator have informed the tour operator of a payload restriction which might be compounded further by weather conditions such as a water contaminated Oxford runway, still air conditions, high outside air tempertures and/or unfavourable en-route winds?