KC-135T of the Pennsylvania Air National Guard's 147th Air Refueling Squadron (Pittsburgh) refuels an F-15C of the 71st Fighter Squadron (Langley AFB)
Note: This should be read in conjunction with Aerial Refueling - Key to American Airpower (Part One). As with that part, Part Two will feature graphics from one of my cruise lectures.
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| Flying boom refueling - Probe-and-drogue refueling |
In this part, we will examine the two methods of aerial refueling, the advantages and disadvantages of each, and how they affect military operations.
Fortunately, the U.S. Air Force KC-46A Pegasus is equipped to conduct both flying boom and probe-and-drogue refueling, making it compatible with virtually every U.S. military fixed-wing aircraft requiring aerial refueling.
Flying boom refueling is favored by the Air Force. It's principal advantage is a much higher fuel transfer rate than the probe-and-drogue refueling.
The flying boom can transfer about three to four times the rate of a typical probe-and-drogue system. While this provides little advantage when refueling fighters, whose fuel systems cannot accept fuel at the boom's maximum rate, it is invaluable for large aircraft such as bombers, transports, airborne warning and control systems (AWACS), maritime patrol aircraft, and reconnaissance aircraft, all of which may need to take on tens of thousands of pounds of fuel during a single refueling.
At one point in my career, I was assigned to an RC-135 unit. We routinely flew missions lasting up to 20 hours - and occasionally even longer - requiring rendezvous with two KC-135 tankers about halfway through each sortie. Even using the flying boom, completing the refueling sequence could take 45 minutes or more. Had we relied on probe-and-drogue refueling, those missions would have been far less practical.
In the Air Force, we often joke that flying boom refueling is "full service"- the boom operator puts the gas in your tank. Probe-and-drogue refueling is "self-service" because the receiver pilot has to fly the probe into the basket himself. It's all good-natured interservice humor.
So what are some of the planning factors that must be considered? Neither the U.S. Navy nor the U.S. Marine Corps operate boom-equipped tanker aircraft. During carrier operations, tactical aircraft are normally refueled by other aircraft within the carrier air wing, most commonly F/A-18 Super Hornets equipped with buddy refueling stores.
The Navy is fielding the MQ-25 Stingray unmanned tanker to reduce this limitation. Every Super Hornet assigned to the tanker mission is one fewer aircraft available to carry weapons on strike or air-defense missions.
Fleet support by land-based Navy P-8 Poseidon maritime patrol aircraft and Navy E-6B Mercury airborne command post relies on aerial refueling by the Air Force - the airframes require boom refueling. The bottom photo here is a USAF KC-135 refueling a USN E-6B over my house (red dot) on the south Oregon coast on aerial refueling track AR-8A South.
Here is where it can become more complicated. The United Kingdom, one of closest allies, operates four type of Boeing aircraft. These Royal Air Force (RAF) assets are the E-7 Wedgetail airborne early warning and control aircraft, the RC-135 Airseeker (similar to the USAF RC-135V/W Rivet Joint) signals intelligence reconnaissance platform, the P-8A Poseidon maritime patrol aircraft, and the C-17 Globemaster III heavy transport.
These aircraft all require flying boom refueling. However, the RAF Voyager tanker fleet is equipped eclusively for probe-and-drogue refueling. Currently there are no plans to retrofit any of the tankers to add a boom capability, nor are there plans to acquire such tankers in the future.
As a result, the RAF must rely on allied air forces with boom-equipped tankers for refueling. While some European countries have with this capability, none have anywhere near the capability of the U.S. Air Force.
Let's look at a real world example of how aerial refueling extends the reach of American airpower, even beyond that of the U.S. Navy carriers. At times, there is nothing like five acres of American sovereign territory - and the carrier strike group that sails with it - to project power. At other times, only long-range land-based aviation can reach the target.
This is USAF B-2 Spirit stealth bomber, one of the most advanced aircraft in the world. It is currently the only aircraft in the U.S. inventory that can carry the 30,000-pound GBU-57 Massive Ordnance Penetrator.
That aircraft-and-weapon combination was employed during the June 2025 American strikes against Iranian nuclear facilities. Seven of these bombers flew over 36 hours to and from the targets in Iran.
The operation required refueling support from 32 tanker aircraft operating from multiple locations. Without aerial refueling, a mission of that distance and duration would simply not have been possible.
While the fighters and bombers may get the headlines, much of what they accomplish relies on the tankers. Aerial refueling is not simply a support function, it is what makes American global airpower possible.
