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Fuel Orders in Pounds: A Quick Guide for New Line Techs

Sooner or later every new line tech hears it: “Give us 4,000 pounds.” Your truck counts gallons. The crew is thinking in weight. In between is a conversion, a few questions, and a good habit of saying the number back.

The math is covered in detail in the weight per gallon guide. This post is about getting the order right before the math even starts.

Why Crews Think in Pounds

Turbine aircraft track fuel by weight. The gauges, the performance numbers, and the weight and balance all work in pounds or kilograms. Fuel is bought and metered by the gallon, so somebody has to convert, and industry reporting has long pointed to the conversion, or the wrong amount or unit being passed along, as a source of fueling mistakes.

At least one FBO chain has run trucks that show pounds as well as gallons, using a fixed 6.7 pounds per gallon. That helps with communication, but it's still an estimate, which matters more than it sounds.

Ask Before You Convert

A fuel order can go wrong before any arithmetic happens, through a misunderstanding about what the number means. Before you work out gallons, be sure of four things:

• Total or add? “4,000 pounds” can mean fill to 4,000 total on board, or add 4,000 to what's there. Those can be very different uplifts.
• Pounds or kilograms? Crews who fly internationally may work in kilograms. 4,000 kilograms is about 8,818 pounds, more than twice the fuel.
• Which tanks, and how much in each? Some orders come per side or per tank. Ask how they want it split.
• Which grade? Confirm the grade every time, as the misfueling guide explains.

Why 6.7 Is Only a Starting Point

The Jet A specification allows a range of densities, so the weight of a gallon depends on the batch. Here's what a 4,000-pound order looks like on three different batches, with gallons at 60°F from AvGrav's correction math:

Using 6.7 for all three gives 597.0 gallons. On the light batch, that delivers about 3,929 pounds, 71 short. On the heavy batch, about 4,129 pounds, 129 over. Neither is a disaster on a ramp estimate, but it's not what the crew asked for, and it adds up on bigger orders.

The fix is to use the pounds per gallon from a corrected reading of the fuel you're actually pumping. If your meter isn't temperature compensated, there's one more step, covered in the weight per gallon guide: on an 85°F day, those 595.0 gallons at 60°F are 602.7 gallons on the meter.

Say It Back, Then Write It Down

• Read the order back in the crew's terms before you start: “Adding 4,000 pounds, 2,000 per side, Jet A.” It takes five seconds and catches most misunderstandings.
• Ask about rounding if the gallons come out uneven, rather than guessing which way they'd prefer, and follow your procedures.
• Tell the crew what went in: the gallons, and the weight if they want it, worked out from the gravity of the fuel you pumped. The uplift check post explains why they'll compare it with their gauges.
• Put it on the ticket so the order, the uplift, and the numbers behind them are all in one place.

Where AvGrav Fits

AvGrav shows pounds per gallon with every corrected reading, so the number you divide by is the real one for today's fuel. After fueling, enter the gallons in Fuel Volume and it gives Net Volume @ 60°F and Total Weight in pounds or kilograms, the figure the crew can check against their gauges. It works from gallons to weight, so for a pound order, divide by the pounds per gallon it shows. It's a reference tool, not a replacement for your procedures.

For crews heading somewhere far away, AvClock, from the same developer, shows the local time and UTC at their next stop.

Common Questions

AvGrav and this guide are reference and convenience tools, not certified measurement instruments or a substitute for a calibrated hydrometer, thermometer, or your organization's official procedures. Always follow your organization's quality control program and applicable regulations before accepting, rejecting, or releasing any fuel.