In the Persian Gulf War, Air Force KC-135 and KC-10 tankers performed more than 51,000 in-flight refuelings. These giant filling stations in the sky transferred some 125 million gallons of fuel to other planes. Moreover, the tanker force missed not a single wartime refueling rendezvous.
For a public mesmerized by the war images that flashed across its TV screens, Tomahawk cruise missiles and smart bombs may have been the stars of the conflict. Many professional war planners, however, give top billing to the tanker fleet.
The dependability of USAF's aerial refueling aircraft was also the key to the success of Operation Restore Hope, the recent US humanitarian effort in Somalia. In nearly three months of operations through February, for example, the Tanker Task Force from Morón AB, Spain, posted a 100 percent effectiveness rate, meaning it never failed to deliver the fuel on time.
The Somalian effort was choreographed. "Everything, including refueling the C-5s and C-141s on their way to Africa, was tightly scheduled," said Col. James Dickensheets, the task force commander. "If we missed a refueling over the Atlantic Ocean or Mediterranean Sea, those planes would have to stop somewhere in Europe, throwing off the entire schedule" for delivering desperately needed supplies.
Air Force leaders have long recognized but are now reemphasizing that a key to projecting worldwide airpower resides in one of the less publicized elements of the force: the more than 3,000 men and women who fly aboard tankers. Each tanker pilot can tell a story of the moment when the dangers-and significance-of the refueling mission were brought home in dramatic fashion. For Capt. David Horton, it came in the Gulf War when an Air Force fighter pilot, flying on fumes, sent out a desperate radio call for help.
Captain Horton was at the controls of a KC-135R on the night of January 17, 1991, according to an official Air Force account of the incident. It was the opening phase of the war with Iraq. The young captain, who was based at Grissom AFB, Ind., was flying a lazy oval near the Iraqi border when his radio crackled to life. "Mayday, Mayday," called an unknown pilot. "I want to declare an in-flight fuel emergency."
Running on Empty
The message came from the pilot of an F-117 Stealth fighter. The plane, returning to base after making an attack on Baghdad, was flying in extremely foul weather and had missed its planned postattack refueling action. The stealth jet's fuel tank was dangerously close to empty.
The F-117 had asked an E-3 Airborne Warning and Control System (AWACS) plane for directions to an alternate landing area. Captain Horton, listening in, realized the fighter's new course came directly past his KC-135. The tanker pilot alerted the E-3 and began flying to a higher altitude, seeking to break out of heavy cloud cover. Finally, at 27,000 feet, he popped into clear air.
When the F-117 showed up, however, its pilot had trouble maintaining the proper altitude for refueling. Holding position was made difficult by the presence in the weapons bay of a heavy, unused smart bomb. As time slipped away, the F-117 pilot warned the refueling boom operator, "We've got one shot at this."
The F-117 rose from the clouds, seeking the KC-135. As he eased in behind it, the fighter pilot throttled back to match the tanker's speed. The boom was lowered into the tanker's wake, and the operator maneuvered it into position as the fighter struggled to hold its place. Finally the connection was made, and the precious fuel began pouring into the F-117.
Because it was carrying the extra weapon, however, the fighter was still struggling to hold a position. Captain Horton executed a so-called "toboggan" maneuver. With the two planes joined by the refueling boom, the tanker pilot dropped the KC-135 into a descent. The F-117 pilot tucked in behind, picking up the speed he needed to hold the fighter in place.
The refueling was completed and the F-117 roared away, but not before its pilot called out a thank-you. "You guys really saved my bacon," said the fighter jock.
The process of conducting in-flight fillups has changed a great deal since 1918, when a Navy Reserve pilot snagged a bag of sand from a barge in an early test of a primitive air refueling concept. The path has been one of steadily increasing skill and sophistication.
Many of the earliest refueling attempts were nothing more than aerial stunts, as in 1921 when wing-walker Wesley May in Long Beach, Calif., hopped from one biplane to another with a five-pound can of gas strapped to his back.
In World War II, the US Army Air Forces did not conduct aerial refueling operations, though it seriously considered doing so, especially in the Pacific theater. One plan developed in 1942 called for launching B-17 bombers from Midway Island to hit targets in Tokyo, refueling the bombers before or after the raids. The role of refueler would have been played by modified B-24 bombers.
After the war, the Air Force got serious, but progress was slowed by the technological immaturity of the refueling devices. The receiver aircraft would have to snare a contact line trailing from the tanker and winch in the refueling hose to make the connection. There was nothing automatic about it.
In the Korean War, refueling during combat operations took place for the first time, with promising results. In 1954, the Air Force bought its first KC-135A Stratotankers from the Boeing Co., and, a decade later, the service had taken delivery of 732 KC-135s. Many of these are still flying; some are expected to continue flying well beyond the turn of the century.
The Air Force continued to develop its expertise through the late 1950s and early 1960s. The war in Vietnam sparked a dramatic expansion of the use of in-flight refueling. After the war, the Air Force sought to bolster its capabilities with an advanced tanker aircraft, a concept fulfilled by the KC-10. McDonnell Douglas began work on this aircraft in 1978, and the first plane entered service three years later. The KC-10 was a significant advance in USAF's refueling capabilities. Each KC-135R holds around 200,000 pounds of fuel; the KC-10, which itself is air refuelable, carries up to 350,000 pounds.
In-flight refueling, though all but taken for granted in today's Air Force, can be a risky proposition even in peacetime. When the receiver is a large aircraft like a C-5, the tanker pilot has to worry about the aerodynamics of two large bodies coming so close together in midair. If he or she isn't careful, the flight of the two aircraft can form a powerful vacuum that can suck the two air vehicles together. In addition, the flight of the cargo plane can create a huge "bow wave" of air that can sweep over the tanker's elevators, giving the tanker pilot a nasty in-flight surprise.
When it comes to aerial refueling, fighters are easier to service. "You don't even feel them behind you," said Maj. Rick Antaya, a KC-135 pilot. He noted, however, that the experience level of the pilot flying the receiving aircraft makes a big difference. "Even in the worst of turbulence," said Major Antaya, a veteran pilot can hold position. That is not always the case with a rookie, said the major. "It doesn't take much to scare them off the boom."
The receiver also has a major task on his hands. The rule of thumb, say operators, is that for every time the tanker pilot touches his throttles the receiver has to make three power adjustments.
AWACS Helps Out
There are three principal types of refueling operations. One is the "point-parallel" type, in which two aircraft come toward each other. At the tanker's direction, the receiver aircraft executes a 180° turn, reversing direction and ending up just three miles in front of the tanker. This tactic is most commonly used in refueling large aircraft.
Second is the "en route" approach, which can be used by any type of aircraft. Here, the tanker and his customer are given refueling coordinates and a specific time to rendezvous. "You've got to be there on time," noted Capt. Al Self, a ten-year veteran of tanker operations. "Otherwise, it's a big blue sky."
Finally, in congested airspace, tankers can do their work under an AWACS-directed operation called "fighter turn-on." The giant airborne warning and control aircraft communicates with a tanker and a receiver. It gives the tanker heading and airspeed commands. It vectors the fighter toward the tanker until the combat jet acquires the tanker visually or on radar. Then the receiver moves into position.
There is a common thread to all three techniques: Once the receiver is within a half-mile of the tanker, the boom operator becomes the key figure. He or she is lying on his or her belly in the tanker's rear area, watching the operation unfold.
In the KC-10 tanker, the boom operator's station is pressurized and air-conditioned and includes a rear window and wide-angle periscope system. By blinking commands with the lights on the tanker's underside and speaking with the fighter pilot over a radio, the "air refueling operator" steers the receiver into a rectangle of airspace below and behind the tanker.
Once the receiver is in place, everything depends on the boom operator, who mechanically flies the boom into the receiver aircraft's refueling receptacle, using a digital fly-by-wire system. "That's probably the trickiest part of the operation," said Captain Self.
The Gulf War marked a significant departure for Air Force tanker crews. In peacetime and in small-scale conflicts, tankers had typically remained well away from the danger zone. The war with Iraq, however, found tankers deliberately flying much closer to hostilities. When flying missions north of the border, tanker pilots frequently saw hapless Iraqi antiaircraft batteries firing wildly into the air. "I remember the first time that I copied down the coordinates and plotted the [refueling] track," stated Maj. Diane Byrne. "I didn't think tankers were supposed to go that close to the action."
On her deepest penetration into Iraq, Major Byrne came within 400 miles of Baghdad-not unusual for tanker crews. There was no great philosophical change, according to Maj. Gen. Frank Willis, deputy chief of staff for Requirements for Air Mobility Command (AMC) at Scott AFB, Ill. Rather, it was a function of the geography of the war theater.
With the war barely one week old, Major Byrne was assigned to pilot a KC-10 over Iraqi territory. Once there, she was told to drop to 12,000 feet from the safety of her 25,000-foot cruising altitude to find a C-130 in need of fuel. The danger from Iraqi antiaircraft fire forced the Air Force to carry out refueling operations in virtual radio silence.
Bumps in the Night
When Major Byrne arrived at 12,000 feet, she found bad weather and no C-130. She began descending by increments of 1,000 feet, searching for the fuel-hungry cargo plane. Eventually, she brought up a single emitter to check for her target. Successful at last, Major Byrne began pumping 30,000 pounds of fuel into the C-130. "My biggest concern was hitting another airplane," she said. "You just hope you don't hit anything."
Often, several different tankers could be scattered along different points-though at different altitudes-on the same oval. For safety reasons, the Air Force rarely refuels below 10,000 feet, but Major Byrne said that she and her AWACS controllers were prepared to drop as low as 3,500 feet to make the connection.
Bad weather was a constant hazard. There were sandstorms, dense sea fog, and scorching heat. All posed major challenges to tanker aircrews. One day in late January 1991, a sea fog blew in off the water. With visibility at zero/zero, Major Byrne's KC-10 was led into position on the runway, where it sat, waiting for the required 1,000 feet of visibility. After a long wait, the fog lifted far enough for the runway supervisor to give the go-ahead, but as the KC-10 sped down the runway, the fog suddenly closed in again. Major Byrne pressed ahead, however, and, after a few anxious moments, the tanker broke into the clear.
For Air Force leaders, the Gulf War highlighted the vulnerability of the tankers. KC-10s and KC-135s are basically defenseless, little more than flying fuel tanks. Tanker pilots rely on the accuracy of preflight intelligence assessments, orbiting fighter escorts, and nearby AWACS to alert them to any threats. During a mission, tanker commanders wouldn't know unless told that they were being "painted" by an enemy acquisition radar.
"For a good number of years, there's been concern about our exposure to any possible threat," said General Willis. He added that, until they went into action in Desert Storm, tankers tended to operate at high altitude and well behind the forward edge of battle area.
The now-defunct Strategic Air Command, located at Offutt AFB, Neb., developed a "tanker defensive concept of operations." It called for tankers to guard against infrared and radar-guided weapons by using a combination of passive detection, threat avoidance, and situational awareness. Now, as a result of the war's lessons, AMC (for tankers, the successor to SAC) is eyeing refinements to that stance.
The Air Force Electronic Combat Office at Wright-Patterson AFB, Ohio, began a tanker defense survivability analysis late last year. The office has already reached some conclusions.
What's the Threat?
General Willis said initial results suggested that it would be too expensive to outfit tankers with self-defense capability. The emphasis, he said, will remain on giving the pilot the tools to know what's happening. "The aircrew is interested in knowing the threat out there," said General Willis.
Ideas on the table include satellite data links as well as possible tie-ins to the Joint Tactical Information Distribution System (JTIDS), a data terminal that would help numerous friendly aircraft in an area share various types of information to provide all aircraft pilots a more complete picture of the air battle scene. The Air Force conducted a feasibility demonstration of JTIDS on a KC-135 during a recent Red Flag exercise.
A key requirement for tanker jockeys is flexibility. For Captain Self, that premium on flexibility was illustrated by a dicey situation that came up during Desert Storm. One night, early in the war, he was commanding the middle KC-10 in a three-tanker operation. Trailing behind in formation were eighteen Marine Corps AV-8B Harrier jump-jets.
Suddenly, a fireball lit the sky. A Harrier had ripped the drogue receptacle off the lead KC-10. Sparks shot about as the basket-like drogue and twenty feet of hose slapped against the jet's side. "It scared us half to death," said Captain Self, who was now the lead tanker and had to make a quick decision: Should he continue, hoping to pick up enough fuel somewhere for all of the warplanes in his wake? Or divert to a nearby island base?
Gambling that another tanker would materialize to top him off, Captain Self pressed on. With the need to fuel ten Harriers rather than his original six, the KC-10 boss needed more gas-and fast. He got it. He quickly arranged a short-notice linkup with another tanker, which dumped tons of fuel into his aircraft. Topped off, Captain Self passed the fuel to the Harriers, which proceeded about their business as if nothing unusual had occurred.
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