Eyewitness: Inflight Refueling

Alongside the Boomer for one of military aviation’s most critical maneuvers.

In the skies above Iraq in 2017, a KC-135 Stratotanker pumps gas into a B-52 Stratofortress. KC-135s and B-52s have hooked up for more than 60 years. (USAF/ Airman Jordan Castelan)
Air & Space Magazine

The Air Force has never learned the friendly skies routine. The interior of the KC-135 was like the inside of a long pipe—gray, poorly lit, utilitarian, lined with the girders and rivets that held it together. A few passenger seats were installed up near the cockpit. You could talk over the engine noise, if you screamed.

We were waiting for our B-52. The boom operator paced, wearing a radio headset and trailing a long cord. When the bomber arrived, the operator would guide its pilot to our tanker to begin the refueling operation. We all wore shoulder bags with masks and small bottles of oxygen in case of decompression.

Beneath us were many, many gallons of jet fuel. The airplane can carry 190,000 pounds of it, a major told me. The thought of all that combustible liquid beneath the floor will definitely concentrate your mind if you have to land with hot brakes. I did it once in Thailand when we had bases there, and the Air Force met us with most of the world’s fire trucks. The KC-135, which, after more than 60 years of service, is gradually being replaced by newer tankers, is not a dangerous aircraft. It is nonetheless a winged gas tank.

I had sat in the cockpit for the takeoff, which proved more interesting than I had expected. The airplane is a heavy brute—maximum gross takeoff weight is about 300,000 pounds, although we were well below that for this practice flight—with four awful, smoky turbojets that are so noisy they are not allowed at civilian airports. (More than 400 KC-135s were retrofitted with quieter CFM56 engines in the 1980s.) Either the runway had slight swells in it or the weight of the tanker makes it indecisive when taking off. Whatever the reason, the airplane lumbered along, runway whipping past faster and faster, until suddenly there was a slight roller coaster sensation…uuuup...doowwwnnn. We sort of surfed into the air.

An hour or so into the flight, the boom operator yelled, “Bomber’s back there.” He and I walked back to the tail and climbed down into what looked like slit trenches. We lay on our stomachs and peered down through four miles of nothing to the desert of west Texas—drab browns gashed as if high winds had carved up the earth millions of years ago. In front of us, just under the window, was the boom-control panel. A handwritten cardboard sign taped to the console gave the call signs of the tanker (“Canis 09”) and the bomber (“Rambo”).

Miles behind us, the bomber hung in space, a black dot against a tower of cloud. It grew slowly.

The boom-control panel has two sticks. One, held in the boomer’s right hand, moves the boom up, down, left, and right. Actually the boom controls move small wings—“ruddervators”—on the end of the boom that fly it in the desired direction. The response was mushy and a bit delayed, but easy to get used to. The other stick extends and retracts the probe. It hisses when it moves. The panel also has knobs that set an automatic disconnect system so that if the receiving craft were to drift too far to one side, the boom would automatically let go. Although refueling is simple, large forces are involved, and the bomber could easily tear the probe from the tanker.

Americans do a lot of air-to-air refueling and are good at it. The Russians do it too, but not to the same degree. For U.S. flying forces, refueling is not an occasional trick or exotic technique but a mainstay of U.S. air power. U.S. Strategic Air Command bombers depended on it, routinely using KC-97 tankers in the 1950s that were derived from the B-29. In 1957, the Air Force introduced the KC-135 Stratotanker, a jet that could keep up with new jet fighters and bombers. Today’s version of SAC, Air Force Global Strike Command, still gases up with the -135, and also calls on the McDonnell Douglas KC-10. So far, the Air Force has approved only domestic use of its brand new 767-derived tanker, the KC-46, as Boeing irons out its kinks. But in regions of the world where U.S. fighters and bombers cannot depend on landing rights, tankers are vital, so the KC-135 soldiers on.

The B-52 crept closer, an evil-looking thing. Some confused instinct deep in my mind urged: Let’s go faster. It’s gaining. But the bomber’s approach was actually slower than usual because this was a training flight. The Air Force doesn’t say so, but good pilots can slap their aircraft on and off the boom much faster.

“Fighters are really fast,” the sergeant told me. “Agile. They stay on the wing in formation and just twitch back onto the boom. It’s pretty. We can get them on and off in three minutes, exclusive of pumping.”

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During the Vietnam War, KC-135s, according to Boeing, refueled combat aircraft 813,000 times. Since then, the -135s, like the B-52s they service, have gotten new engines, new electronics, and new aluminum alloy skins on their wings. (USAF / Sgt. Douglas Nicodemus)

Like many things the military does, refueling is dangerous. The Air Force flies hundreds of thousands of refueling operations every year, there being only two ways to do dangerous things safely—don’t do them at all or do them all the time to stay in practice.

One hundred yards back, the big green monster oozed closer, flying precisely now. The boom operator became more attentive. Below us Texas disappeared in piles of cloud. The intercom chatter assumed the highly focused casualness of military men who do not want to make a mistake. Refueling accidents are rare but serious.

Should anything go wrong, the boom operator would call, “Canis Nine, breakoff, breakoff, breakoff,” whereupon the KC would climb at full throttle and the bomber would dive 1,000 feet. This works best if the bomber has not already rammed the tanker.

The bomber was 40 feet away and creeping. I could see odd little ripples in the metal skin of its wings. B-52s have wrinkles. The flight was a geriatric assignation, really. The B-52 first flew in 1954, and the last one came off production lines in 1962.

At 20 feet, the bomber loomed. I could see a hand through its canopy. A kid with a peashooter could have aimed at individual rivets. The cockpit windows were dark and sinister, like the eyes of a great evil wasp. The precision of this curious ballet was startling: Flying at several hundred knots, the bomber was creeping up on us at less than a walking pace, and as accurately. The boom operator talked quietly into his microphone, guiding the beast in.

He can do it at night in radio silence, as was done in the 1986 Libyan raid, but the crews have to be very good. Tankers have small signal lights under the fuselage, worked by a toggle switch on the boom operator’s panel to signal the pilot to creep forward or backward. Night refueling can get complicated: When the receiving aircraft are camouflaged, the boom operator’s depth perception often fails.

On the Libyan operation, 28 KC-10s and -135s refueled the strike force—18 F-111 fighter-bombers and four EF-111 jammers. During the 6,000-mile roundtrip night mission, there were multiple silent refuelings. Many of the tanker and fighter crews were veterans of air combat in Vietnam.

The bomber was so close I could see a wedding ring on the copilot’s hand. The boomer flew the boom over the receptacle behind the cockpit and extended it. The long shiny pipe slid into the opening—ssssss!—and the locking mechanism took hold. If this were for real, the pilots in the KC’s cockpit would have started the four pumps and monitored the flow. Instead we just flew smoothly for several minutes. It looked easy. Shortly we would see that it wasn’t. The copilot of the B-52 was going to try his hand at connecting.

‘’You gotta watch copilots carefully,” said the boomer. “They’ve got less experience. They have to learn somehow, but you gotta watch ’em.” Like student brain surgeons.

Sure enough, the bomber edged forward awkwardly. First it came too fast and then cut back too much—not wild, but definitely ragged. Finally we got the boom into him, but he kept swinging off to the right, close to the disconnect limits. He wasn’t flying badly, but the guy was obviously still learning. At one point he surged up toward us and I found myself grabbing for a girder and bracing for the shock. It wasn’t really that close, but someone said over the intercom, “Keep your heads up on this one.”

Time and again the bomber fell back and came forward for the boom. Periodically, the boomer sent a few gallons through the boom to keep the mechanism lubricated. The fuel sprayed from the overflow tubes into the airstream. A couple of times the bomber went too far to the right and the boom disconnected. The fellow was getting better, although he never equaled the syrupy smoothness of the first pilot. He would have to learn more another day. It was almost time to go home.

We left the harsh, jagged desert and flew over a vast expanse of crenellated clouds, huge puffy towers rising almost to our altitude. Great cloud cliffs tumbled sharply, billow after billow, ledge after vast complicated ledge, down to cloud valleys. The slanted afternoon light left the deeper canyons dark and shadowy, the eastern scarps dirty yellow blending to luminous snow. Wisps of mist, unattached to the looming walls, glowed over the depths. Against the gleaming backdrop the bomber looked weird, alien.

“Pretty, isn’t it?” said the boom operator. The bomber dropped away after a final approach and headed back to its base. Box lunches and coffee waited up front, but we lay for a few minutes watching the clouds. There are reasons for flying other than the pay.

Former Vietnam War correspondent Fred Reed writes from his home in Mexico.

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