Fuel Offload: Giving Gas at Altitude

Fuel offload is the aviation fuel a tanker passes to a receiver aircraft in flight. The two aircraft stay connected while the transfer runs, and the tanker keeps flying on what remains in its own tanks. The figure printed on a fact sheet is almost never the figure a receiver actually takes aboard. This article separates the two, using the numbers the fact sheets publish and stating plainly where those pages stop.

Fuel offload is fuel given to receivers, not fuel thrown away

Aerial refueling transfers aviation fuel from one aircraft to another during flight. It extends flight duration and range, and it can let an aircraft take off with a lighter initial fuel load and top up later. Fuel offload names the useful half of that exchange: the quantity that ends up in the receiver's tanks.

It is not the same operation as jettisoning fuel overboard. Jettison reduces aircraft weight and gives fuel to no one. Offload moves fuel from one aircraft to another through a connected line. Any text that mixes the two is describing a different subject.

How much fuel can a tanker actually give away?

KC-46A Pegasus: the published figures

The Air Mobility Command fact sheet for the KC-46A Pegasus, current as of April 2025, lists a fuel capacity of 212,299 pounds (96,297 kilograms). The same page states that the aircraft transfers fuel by boom, by centerline drogue, and through optional wing aerial refueling pods, that it supports simultaneous multiple-point refueling with the pods installed, and that the boom operator controls these systems.

KC-10 Extender: a retired benchmark

The US Air Force fact sheet for the KC-10 Extender records six tanks carrying over 356,000 pounds of fuel. It also records the type's retirement on 26 September 2024, so its figures are read historically. The page still carries an inventory entry written before the retirement, which should not be quoted as a present-day count.

Both figures answer how large the tanks are. They do not answer how much fuel a receiver gets on a given mission, and neither page claims to.

Capacity is not the same as useful offload

Fuel remaining onboard the tanker also supports its own flight. Every pound is committed either to the tanker's own flight or to a receiver, and a pound cannot be committed twice. Capacity sets a ceiling on offload, never a delivery promise.

How much a crew holds back for the tanker's own needs is a planning matter the public pages do not encode. The Air Mobility Command fact sheet publishes no mission-specific offload guarantee and no reserve formula, and this article does not invent substitutes for either. A single fixed number offered as the offload of a tanker, with no mission attached, is a number the fact sheets do not stand behind.

Does a maximum transfer rate tell you how much fuel you get?

No. Rate and quantity answer different questions. The KC-10 fact sheet publishes maximum transfer rates of 1,100 gallons per minute through the boom and 470 gallons per minute through hose-and-drogue. Two cautions attach: they are maximum rates, not typical sustained flow, and they describe fuel moved to a receiver through a connection, not fuel poured out overboard.

Turning a rate into a quantity takes time on contact. Multiply gallons per minute by minutes connected and you get a volume; without the minutes, the rate only says how fast the total could grow. The comparison runs one way: the KC-10 rates exist on the fact sheet; the KC-46A page publishes no numerical boom flow rate.

The table collects only what the two fact sheets publish. Entries marked not published are limits of those pages, not zeros.

The receiver asks, the tanker answers

Offload is usually counted from the receiver's side. A receiver arrives with a requirement, contact is made, fuel moves while the two aircraft stay connected. No page cited here spells out the request phrasing or the fuel accounting between crews, and this article does not reconstruct it. The logical frame still holds: any offload is bounded by what the tanker carries, what the receiver can accept, and how long the connection lasts. The smallest bound governs.

Connection compatibility decides whether the offload happens at all

Boom and probe-and-drogue are different connection methods, and fuel only moves through a compatible pairing. The reference article on aerial refueling keeps the two families distinct, and the tanker pages confirm the split: the KC-46A works through its boom, its centerline drogue, and its optional wing aerial refueling pods, and with the pods installed it can refuel at multiple points simultaneously. The boom operator controls the refueling systems.

A tanker can also be a receiver. Receiver-capable KC-10s could themselves take on fuel to extend delivery range, chaining offloads: the tanker takes gas, then gives gas farther along the route. That is now a historical note for the KC-10, retired since 26 September 2024.

What the fact sheets publish, and what they leave out

• The Air Mobility Command KC-46A page, current as of April 2025, publishes capacity (212,299 pounds, 96,297 kilograms), simultaneous multiple-point refueling with pods installed, and the boom operator's role. It publishes no mission offload guarantee, no reserve formula, and no boom flow rate.
• The US Air Force KC-10 page publishes capacity over six tanks, both maximum transfer rates, the retirement date of 26 September 2024, and the receiver-capable feature. It retains an inventory entry that predates retirement and must not be read as current.
• The Wikipedia article on aerial refueling supplies the definitions used throughout: fuel transferred between aircraft in flight, extended duration and range, lighter takeoff loads made possible, connection maintained during transfer, remaining tanker fuel supporting the tanker's own flight, and the distinction from jettison.

The pattern is consistent. The pages describe aircraft: tank sizes, transfer methods, maximum rates where given. They do not describe sorties: no per-mission offload figure, no reserve arithmetic, no distance-and-return chart. A fact sheet answers what the machine is; a mission plan answers what it does on one flight.

Reading offload numbers without being fooled

• Check the unit. Pounds of capacity, gallons per minute of rate, and gallons delivered answer three different questions.
• Check the verb. Carries describes tank size; transfers at up to describes a ceiling on speed; neither states a delivered quantity.
• Check the direction. Fuel accepted by a receiver is offload; fuel jettisoned overboard is weight relief, and no equation from one applies to the other.
• Check the date. KC-10 figures describe an aircraft retired on 26 September 2024; the KC-46A page is current as of April 2025.
• Check the gaps. Where a fact sheet publishes no figure, the honest statement is that the figure is not published, not zero.

Questions or corrections reach the Offload editorial team at contact@air-refueling.com.