Fuel: How much is enough?

#1 of My Series: Behind the Cockpit Door

“You never can have too much fuel, unless you are on fire.”  That’s what pilots jokingly tell each other until they realize that there’s a point at which having more fuel goes from being a good thing to being a big problem.  

Returning to my Boeing 757-300 in Las Vegas one day after checking our flight plan for the return trip to Houston, I was approached by a terrified fueler who confessed to me that he had confused my airplane with the one parked at the gate next door which was headed for Newark, NY.  Horrified at having put almost 3 extra hours of fuel in my plane, he explained that the flight to Newark always parked at this gate and it was his mistake in not reading carefully the ship number painted on the nose gear door before he started to fuel the airplane to be sure he had the correct airplane.  

Now it would be a critical issue as to whether we could make the flight without having to defuel the airplane since we had both a maximum takeoff weight (which was no problem on this relatively short flight), but more importantly, a maximum landing weight concern.

You might think that fueling an airliner for an upcoming flight is akin to refueling your car but precise fuel planning and then verifying that the airplane has the fuel on board (FOB) which you requested is another crucial concern and is definitely at the top of every pilot’s critical preflight list. 

When considering fuel for a flight, pilots thoughts range from do I have enough fuel, to will I have to fight with the dispatcher (sitting in his comfy office many miles away) for extra fuel, to am I Iegal to begin or continue the flight, to do they have enough time to get me all the fuel I will need, to will the airplane actually be heavier than planned and burn more than the forecast fuel or possibly need to land overweight (which will require a time-consuming inspection at the destination)? All these issues influence how much fuel is actually boarded for any particular flight. In this case, the key word was one small digit. The fueler had put the fuel load for ship 868 on ship 861 and created a real problem.

Landing overweight has many ramifications, not the least of which are required inspections, decreased tire and landing gear life as well as expensive schedule delays for all involved.  We did fly that flight with the fuel load as wrongly boarded, spending the full flight time carefully calculating how to burn up as much fuel as possible in order not to land overweight. We had to decline any short cuts or expeditious vectors that ATC kindly offered us, explaining that we may have been in the fuel-saving mode yesterday, but today it was a case of needing to burn the excess before reaching Houston to prevent a possible overweight landing.

Having had a career filled mostly with the opposite problem (not enough fuel on board, rather than too much), it was eye-opening to see how the reverse problem could also consume much of one’s focus on what should have been a routine flight.