How do airlines get billed for jet fuel?

If an airliner is at the gate, greedily sucking up $100,000’ worth of jet fuel for a cross-Pacific flight, does the airport keep tabs on the fuel and send the airline a bill?

Is the airport the actual fuel seller here?

Airlines buy their own fuel, often hedging their bets against rising prices - http://www.latimes.com/business/la-fi-airlines-fuel-hedging-20150128-story.html. Delta even bought a refinery.

The airport may be responsible for gasoline services, but the airlines have their own arrangements.

Not usually, in my limited experience. IME the fuel company is a separate entity from the airport. These smaller companies usually have some sort of lease/contract with the airport, as well as a partnership with a large oil company, who provides them with jet fuel or avgas in bulk.

After the plane gets filled, the fuelling company will then bill the operator of the plane for the fuel, at least if you’re a large airline. If you’re not, you will probably need to give them a credit card before you get filled up.

This is what I’ve seen while working at small airports in Canada. It’s probably different at larger airports or with larger airlines.

About 40 years ago I flew with a friend from Miami to a small island in the Bahamas, refueling in Nassau. I paid for gas with a credit card, out the window, just like in Airplane.

:stuck_out_tongue: Huh. I was just gong to cite that scene as a joke.

Paying for the fuel is a simple issue. The taxes are the complicated part. Years ago a friend of my father’s told me his job (for a major airline) was to calculate the fuel taxes to be paid to each state - based on the miles flown above the state.

Not sure if that is true today.

A commercial pilot named Patrick Smith used to write a column for Salon about life as a commercial pilot (called Ask the Pilot). I distinctly remember him mentioning that he was issued a corporate credit card for fuel purchases. That may be necessary in foreign airports, where no prearrangement has been made for fuel to be supplied to the company’s airliners.

QFT. My experience was about fifteen years ago, and I doubt it has changed much.

Also, corporate credit cards for pilots was/is industry standard. I dealt with about a hundred of them per month. Mostly they were used for fuel, but hotels were also common. The owner of the airline made out like a bandit on the reward points.

For a Cessna type plane, sure, but how does an Airbus A380 operater do it?

You should remember that for major airports serving jet airliners the airlines themselves own their terminal. I’m sure it’s some complicated arrangement of own/lease/rent etc. but it is essentially their territory. All the maintenance & ground crew that service the actual planes (including fueling) work for that airline, not the airport. I would assume that the interior maintenance people (janitorial etc.) and concessions (restaurants, bars, shops etc.) within the terminals are managed by the airline as well.

Not really. The airlines don’t own most of that stuff.

Years ago everybody who touched an airliner was an employee of the airline. That began to go away immediately after de-regulation. As of now pretty much nobody uses their own employees to fuel or clean airplanes. Baggage / cargo handling is contracted out at non-hubs but is usually airline employees at hubs. Maintenance is also contracted out at most out-stations. Hubs & some large out-stations will have maintenance employees on duty. Many out-stations have more in-house maintenance people on duty overnight to run inspections on sleeping jets than they do during the day to cover for the increasingly rare malfunctions.

The days of company mechanics crawling over airplanes before each departure checking & adjusting stuff went away back in the 1970s.
In the terminal …

Big airports are typically government owned in the US. There are only a couple exceptions. Privately managed airports are more common in Europe. The airlines have zero day-to-day control over the terminal concessions, food outlets, janitors, etc. Those are all separate businesses, airport employees, or employees of contractors to the airport itself.

The airlines try to lobby the airport managers (usually government) to provide a nice experience at a low rent to the airline. Both sides are monopolists at heart and it can get pretty heated in private.

Most big airports have one fuel contractor. That contractor sells fuel to everybody. They own the trucks and employ the fueling techs.

Airline HQ figures out the desired total fuel load for each flight then sends a message to the local fueling company dispatch office telling them the what, here, when. We specify the fuel load in pounds or kilos, not gallons or liters. They send out a fuel tech & a truck to do the work.

Sometimes the trucks are tankers. More commonly there is fuel piped under all the aircraft parking spots and the truck just carries a pump to lift the fuel out of a hydrant under a manhole cover and up to the wing. In yet other installations there’s a pump cart sitting at each gate already connected to the underground fuel hydrant. The fuel tech comes out in a pickup truck, hooks the other end of the cart’s hose to the airplane & operates the cart’s pump to upload the fuel.

Once the tech hooks up to the airplane he (99% he, 1% she) operates controls on the airplane fueling panel to set the desired fuel load and distribution. Then he pumps until the airplane decides it’s satisfied & closes off the valves leading to the various tanks. Sometimes he’s involved in transferring fuel between aircraft tanks as well. So the amount that gets uploaded is the difference in pounds / kilos between whatever fuel was already on board and the quantity HQ specified we need for departure. It typically takes 10ish minutes of pumping to load one of my flights. The guys doing uber-long haul in the really big airplanes may see 30+ minutes of pumping to load it all. The hoses are about the size of the ones used from a fire hydrant to a fire pumper truck.

Once the tech’s done he records the *gallons * (or liters) pumped. And does some math to ensure the weight and volume figures line up for today’s measured fuel density. This is supposed to help detect fueling foul-ups. Which it occasionally does.

The tech sends the purchase record back to his dispatch office (either via paper or tablet app or voice radio or …) and goes on to the next airplane. All day long.
The fuel vendor bills the airline somehow who pays the bill somehow. I think it’s pretty much like any other vendor and customer: Vendors send itemized bills monthly to a central accounts payable office with some offered incentive for them to pay promptly. Accounts payable checks that they’re only being billed for what they expect to be billed for, then pays it. There’s lots of e-billing & e-paying nowadays although I don’t have exact details on this stuff.
Naturally there’s all sorts of gamesmanship with tax gifts from well-oiled legislators, and airlines pressuring vendors and vendors pressuring airlines. The business side is cut-throat. The physical logistics are pretty simple.
Airlines are acutely aware of the price paid at each city each day. Typically we only carry the fuel needed for a single flight, plus necessary reserves. But if we’re in a low cost city going to a high cost city we will often load a bunch of extra fuel & carry it to the high cost city. That way we buy less (or none) at the high cost city for the next flight to wherever. It costs a little extra to carry the extra fuel. Some of it will be consumed in the ferry over to support the extra weight. So the planning system includes that factor too. They’re constantly trying to squeeze an extra 10th of a penny per gallon out of the average price paid.
Delta bought that refinery as a different kind of cost hedge. The idea isn’t necessarily that their airplanes burn the fuel their refinery makes. The idea is they can sell their fuel to a distributor and buy fuel from a different distributor at the other end of the pipeline. The financial effect is as if they burned their own fuel at the price they spent making it plus the delta between what they sold & bought the fuel for at the two ends of the pipeline.
In a normal workday I’ll use about $15,000 of fuel. With the recent low fuel prices that’s more like $10K, and it has been as high as $40K. That’s one guy on one workday. We have thousands of guys working 365 days a year. Some fly smaller airplanes; some fly larger. Some put in more or less hours per day. Overall it adds up to a pretty big number.

You have made my head hurt. :rolleyes:

All that math sounds like a good way to become the next Gimli Glider, even though it’s meant to cross-check and prevent running out of gas when you’re 29,000 feet above the nearest gas station. Hopefully, most of the fuel guys are using an app that lets them just plug in requested weight and delivered volume and not have to worry about using the wrong conversion factors.

But at this point, why do we still have to screw around with metric vs imperial units?

It’s not really a question of metric vs imperial but more of weight vs volume. The fuel vendor dispenses gallons (or liters) of fuel; he measures volume and wants to bill based on volume. The airplane is more concerned about the weight of fuel, since that directly affects flight performance. The pilot therefore wants to measure everything in pounds (or kilograms), and that’s in fact what he specifies.

Now available directly from him at http://www.askthepilot.com/

Why does the density of the fuel differ/must be checked for each time?

And how do they spot-measure it? Coriolis meter and temp check?

Density changes with temperature. To ensure you have the fuel load you think you have you need to check it by multiple means, e.g, compare the gauge readings against fuel remaining from the previous flight plus fuel added. To do this accurately you need an accurate conversion for the volume of fuel to weight. Our company procedure is to use a standard density conversion that is suitable for Australian conditions. If the fuel check didn’t work we would get an accurate density from the refueler. If we were flying bigger planes to more varied climates we would have to do as LSLGuy says.

I once had the pleasure of flying a fleet of aircraft that had fuel gauges calibrated in pounds, except one that was calibrated in kilograms. The fuel figures on our paperwork was completed in pounds so this one aircraft was fueled in liters, the gauges displayed kilograms and the paperwork was pounds. They eventually modded it before somebody did a Gimli.

Sometimes there isn’t much choice:

This story is probably apocryphal as there is no mention of it in the deatiled story of “Travel with Amal”

**Richard **covered the reasons for dealing separately with weight & density.

Ultimately all engines burn fuel by weight, not volume. The fact people use gallons or liters to fill their cars is simply convenience and ignorance. For darn sure their cars’ engine computers are doing all their math in weight while operating their engines.
As to metric vs imperial …

The US is standardized on US Customary units (which are not imperial; that’s a misnomer). Substantially the rest of the planet is standardized on SI units (which are not metric; that’s also a misnomer). That means whenever & wherever the two sides touch, conversions are required.

When I fly in the US, all the trucks are dispensing gallons and all the airplanes are gauged in pounds. As are all of HQ’s calcs we depend on. Nobody anywhere in the chain is thinking SI at all.

So now let’s take our purely US customary show to Mexico or Canada or Europe or China or Russia or …

Those folks only know liters, period. Since the guy operating the pump truck is the only minimum wage flunky in the chain, best to make his part as simple as possible. So he sets the airplane load to the numbers on his piece of paper and doesn’t care if those are kilos, pounds, or hundredweights of troy ounces. And HQ’s computer prefigures the number of liters that upload ought to represent, plus/minus a reasonable tolerance. If he gets done and his pump meter displays an upload within the tolerance band he’s happy. If not, he calls his boss.
Not ideal in an abstract sense, but I think you know how easy it’ll be to convert the US to metric. As in “never gonna happen”. All the danger would be during the transition, as **RP **said about their odd-man out airplane. That instability is what invites dangerous confusion.

I could be misunderstanding your point, but internal combustion engines in cars have always metered fuel by volume. Fuel injected or carbureted.