@hunderwear. What you are suggesting is IMPOSSIBLE. Too many checks and balances, too many people involved here for this to happen. There isn't even a remote chance of this happening.
A. The pilots are very particular about this
B. there is an engineer whose job is mainly to dispatch an aircraft with fuel.
C. There is a ground staff assigned tO ensure that refuelling is comPlete in good time.
D. Load controller who does the weight and balance provides weights based on actual fuel on aircraft.
E. the airplane has its own warning systems which tell u even before u start engines that there is something wrong ie not enough fuel to destination.
U have to understand that the policy is to take enough fuel to destination + alternate plus other fuel legally required(plus KQ policy fuel which is higher than legal reqmts). So unlike a car, we don't JAZA as that extra fuel is just dead weight ie ur burning fuel to carry this extra fuel. So we just take minimum fuel reqd for the journey. However, if a turnback is done for whatever reason, like was on the case on that MBA, you have burnt the some fuel, depending on the aircraft between 16-35 kgs per minute on ground and since u have taken minimum fuel required and u have burnt close to 100-200kgs during start,taxi out and then back in, u need a top up.
@VVS. THE NBO-ACC route, the unscheduled stop in DLA can again happen for various reasons.
A. That route is mainly flown over the equator/over the DRC which is known area for severe thunderstorms even at high altitude. Note that the weather forecasts don't accurately predict severe weather and deviations u have to make off track which chews up your fuel enroute. Sometimes u are off track avoiding lightening and thunderstorms by over 80nm(almost 148kms) north or south of your planned fuel efficient track. Also weather forecasts in these areas are not the most accurate.
B. going to the West, winds forecasted might have been headwinds but in flight, several times I have noticed that the actual winds are completely opposite and in some cases, you just have to make a tech stop as the winds are actually unfavourably extreme.
C. Air traffic - you make be planned on the flight plan to fly 38000 feet. However, due to traffic on that level, turbulence etc you are told by ATC to maintain 34000. The lower you are to ur optimum altitude, the more fuel u burn. this scenario is very possible in Kinshasa airspace.