Military aviation changed forever in early 1949. Lucky Lady II, a Boeing B-50 Superfortress, took off from Carswell Air Force Base near Fort Worth, Texas, and flew for just over 94 consecutive hours before landing back at Carswell after successfully circumnavigating the globe.
It was the first time any airplane had circled the world without stopping, and it served as a tremendous show of force for the U.S. Air Force. Sen. Millard Tydings, who was present for the B-50’s landing, said the historic trip proved the “increasing importance of air power in national defense.”
Lt. Gen. Curtis E. LeMay, then the commanding general of the Strategic Air Command, was somewhat less political in stating that the United States could now fly from its own soil to “any place in the world that required the atomic bomb.”
The big bomber got all of the headlines, but its flight could never have happened without the support of air tankers. Lucky Lady II was refueled four times on its global flight by Boeing KB-29s, converted B-29 Superfortresses developed for air refueling purposes.
These KB-29s were the first designated air tankers in the United States military, which acquired looped hose refueling technology from Flight Refuelling Ltd, a British company that worked to develop the technology for World War II but finished it after the end of the war.
Founded in 1934 by aviation pioneer Alan Cobham, FRL intended aerial refueling to be used for commercial flight. The tanker airplane would grapple a steel cable that was trailing behind the receiver, and then the tanker would pull in the line to attach a hose to it. The receiving aircraft then pulled the hose back, connected it, waited for the tanker to fly above it, and let gravity do the rest.
Examples of limited, small-scale aerial refueling date back to the 1920s at least, when simple hoses were used to add fuel to an airplane in flight. Cobham himself had been a part of earlier examples of the practice, although the method his company introduced was the first to catch on and become widespread.
The looped hose method worked — it got Lady Luck II around the world, after all — but it was clumsy. Rarely does the first example of a new technology last long before it is updated. Two new methods were soon introduced: the probe-and-drogue system and the flying boom. Both of them are in use today, but not on KB-29s, which were soon replaced by KC-97 Stratofreighters.
While KB-29s were modified B-29s meant for aerial refueling, KC-97s were dedicated to the task from the jump, and featured heated, pressurized tanks to ensure fuel and cargo would arrive in the proper condition.
KC-97s, adapted from C-97 freighters, helped to pull Boeing out of the post-World War II slump that affected nearly every aviation company. They also made it possible for further worldwide flights to be carried out by the U.S. Air Force’s Strategic Air Command.
As tanker technology improved, so did the airplanes it supported. The Boeing B-47 Stratojet first flew in 1947 and began service in 1951. The B-47’s swept wings and engine nacelles revolutionized large jet technology, and the type set speed records and flew extensive, sometimes global missions. Those Stratojets could not have completed their global flights without KC-97s refueling them along the way.
Of course, more than just the bombers benefit from aerial refueling. The Republic F-84 Thunderjet was the first fighter to be refueled in the air, a common occurrence while F-84s were flying missions during the Korean War.
The B-52 Stratofortress was introduced in 1955, and it was quickly apparent that while the KC-97s could refuel the B-52s, the piston-powered tankers were not ideally suited to the task of keeping up with the jet-powered bombers. The jet bombers were simply too much faster, plus KC-97s were forced to carry jet fuel for the B-52s plus avgas for their own engines. The time was right for a jet tanker to be introduced.
Enter the KC-135, the first Boeing design adapted from the Dash 80, which was designed in semi-secret by Boeing as to not tip other aircraft manufacturers off. The prototype for both the 707 passenger jet and the KC-135, the Dash 80 was formerly known as the Model 367-80 (hence Dash 80), and cost Boeing $16 million.
Since there were no buyers for the prototype before it was built, it was Boeing’s own money — basically two-thirds of all profits the company made since World War II — that went into producing it. That’s a gamble, and it’s one that paid off, as the new swept-wing jet airplane design became a hit both on the commercial side and in the military sphere.
The Air Force initially ordered 29 KC-135s. The first one flew in August 1956, and KC-135s remain in service today, some 62 years later. Although a replacement, the KC-46 Pegasus, is in the works now, the KC-135 could stay airborne until 2040.
Some of the new tanker’s first receivers were the B-52 and some fighters: the Republic F-105 Thunderchief and McDonnell Douglas F-4 Phantom II. Since then, KC-135s have refueled just about everything that the American military has flown.
Jordan Jungwirth, an in-flight air refueling specialist with the United States Air Force, has refueled a lot of different types himself. Jordan is a boom operator, meaning he controls the boom the other airplane uses to refuel.
“How that works is, once I go back there and get the jet in sight, I take over on the radios and talk to the receiver pilot of the jet that’s coming in for fuel,” Jordan said. “We get them into position, which is about 50 feet from the rear of the jet. I’m laying down, looking out the back window. We have lights underneath the jet that I operate, and those guide them in. Once they get within 2-3 feet it’s basically just hand-eye coordination manually, you extend the boom, try to get in the receptacle and start passing gas.”
Jordan’s KC-135 is capable of adapting to the probe-and-drogue method of refueling as well, which is required when it’s time to refuel Navy jets. That process leaves the impetus on the other airplane to line up to start the refueling process.
“With the Navy guys we put that basket on, then we just hold the boom steady,” Jordan said. “They get like five feet from the basket, then when they call they’re stable ready they’ll come in contact and basically be aiming for the basket.”
The history of the KC-135 is something Jordan said he thinks about all the time, especially considering the current fleet is made up of the same airplanes that have been flying since the late 1950s and early 1960s.
“I think about how many thousands of boom operators have had their chin in that chin rest before me,” Jordan said. “All of our jets that are operational came from ’57-’65. The boom system is the same, everything is the same back there, nothing has changed on that. The engines, obviously they keep changing those every decade or so, the avionics keeps getting upgraded, but it’s still the same platform it was back in 1956 when they started testing.”
Jordan said he thinks about both the places the airplanes have been and the people who have been inside them over the years before it was his turn.
“These jets have been around the world, they’ve been to Vietnam, you name it they’ve been there,” Jordan said. “It’s just amazing to think how many different jets that thing has touched, and then how many different people have sat in the pilot seats, the boom operator seats up front and then in the back there doing the aerial refueling. I think about the history of that thing all the time, it’s pretty interesting.”
Despite being such a prolific tanker, the KC-135 isn’t alone in refueling American aircraft. The Lockheed Martin KC-130 Hercules, introduced in the early 1960s, primarily refuels United States Marine Corps aircraft. The McDonnell Douglas KC-10 Extender was introduced in the early 1980s to supplement the KC-135, and the 60-plus KC-10s built are themselves expected to serve into 2043. Naval aircraft such as the Douglas A-3 Skywarrior, and, more recently, the F/A-18 Hornet, used to refuel airplanes from aircraft carriers, have been used in aerial refueling roles as well.
Every airplane type gets retired at some point. Someday, even the KC-135 will transition into warbird status. Its eventual successor, the KC-46 Pegasus, is waiting in the wings, so to speak.
Even though the big bombers and fast fighters are often the aircraft that get the most attention, its air tankers that make it possible for those airplanes to get to wherever it is they need to be, all across the world.