Departure control is a combination of very simple principles. These include calculating the weight of the passenger, their baggage and the cabin baggage; allocating a seat (if required) to that passenger and thirdly ensuring the aircraft is balanced correctly.
Taking these three elements together is basically departure control. In the early days of avaiation, it was done simply with pen and paper, but today all of this is computerised.
Let’s go back a few generations to pen and paper and we can explain the concept in more detail.Our first assumption is we know the type of aircraft flying our route; i.e. the number of seats and seating plan.
In those by-gone years a passenger arrived at check and the agent usually pulled a paper coupon ticket. She would mention this to load control (I’ll come back this later) that she had one female for the flight with a bag. At this stage the passenger was checked in with a boarding card and the coupon was taken in return.
In load control, the passenger (a female plus bag) would be translated into a weight; normally 68kgs for the woman and 12kgs for the bag. (Mind these days the weights given by computer are a lot more generous). Essentially the whole flight was calculated this way and eventually load control would have the weight calculated for the whole flight.
The next stage was for loadcontrol to ensure the weights of the passengers, cargo, fuel and others items on the aircraft did not exceed the manufactures limitations. This was calculated manually. In addition the load controllers had to ensure the aircraft was balanced correctly (i.e. putting the bags and cargo in the right holds). If this was not done correctly the aircraft could have difficulties taking off or at the very least buring too much fuel.