Dark Eagles: A History of the Top Secret U.S. Aircraft Read online

  The assistant secretaries of the air force and navy for research and development also attended some of the six meetings.[112]

  The navy, Convair, and Lockheed were made aware of the general requirements and submitted designs. (As yet, no money or contracts had been issued.) The navy submitted a design for a ramjet-powered aircraft with rubber inflatable wings. It would be carried to high altitude by a huge balloon. The aircraft would then be boosted by a rocket to a speed at which the ramjets could start. The navy proposal proved to be totally impractical. It was determined that the balloon would have to be a mile in diameter and the aircraft's wing area one-seventh of an acre.

  Convair proposed a ramjet-powered Mach 4 aircraft that would be launched from a B-58. This proposal, although far more practical than the navy concept, also had shortcomings. The B-58 could not reach supersonic speed with the aircraft attached. Moreover, it was thought the aircraft's ramjet would suffer "blowouts" during maneuvers. The total flight time for the Marquardt ramjet was less than seven hours, but Convair engineers continued to refine the design.

  Lockheed and Johnson were studying a wide range of concepts for what was initially called the "U-3" project. Many were based on the Sun Tan airframe, but using kerosene fuel. Different size aircraft were looked at, with both two and four engines. Johnson also looked at exotic concepts. These included towing the U-3 to altitude behind a U-2; using a booster stage; carrying the U-3 to altitude under a balloon; aircraft with jet, rocket, and ramjet engines; designs that used coal slurries or boron fuel; vertically launched aircraft; and a design with inflatable wings and tail. In the end, Johnson rejected them all.[113]

  The failure of Sun Tan seems to have had an effect on Johnson's view of the high-speed reconnaissance aircraft. Since the exotic technology of liquid hydrogen had proven impractical, he understood that this new aircraft would have to be based on solid technology.

  Johnson began a series of design studies on April 21, 1958. The first was designated "A-1." The U-2 had been called the Angel by Skunk Works engineers. These new designs would fly far faster and higher, so, accordingly, the A stood for "Archangel."

  In late November 1958, the Land Panel decided that it was possible to build the aircraft. Their report concluded: "The successor reconnaissance aircraft would have to achieve a substantial increase in altitude and speed; be of reduced radar detectability; suffer no loss in range to that of the U-2; and be of minimum size and weight."[114] They further recommended that President Eisenhower approve funding for additional studies and tests. Both Eisenhower and his scientific adviser, Dr. James Killian, had already been briefed on the project. Eisenhower approved the recommendation, and funding was provided to Lockheed and Convair to prepare definitive studies.

  The effort was code-named "Gusto."

  By the spring of 1959, Johnson and his Skunk Works engineers had worked their way up to the A-10, but success seemed elusive. President Eisenhower was intent on a plane with a zero radar cross section. He did not want the Soviets to even know it was there. Kelly Johnson told the CIA that there was no way to accomplish this.

  Work continued on reducing the radar cross section. One idea involved adding wedge-shaped chines made of radar absorbing material to the A-10's cylindrical fuselage. Tests of a small model were successful, and by May 1959 the chines had been incorporated into the A-ll design. This showed a reduction of a full 90 percent in radar cross section. Although not invisible, success was now within reach. In July, a final revised design of the A-ll was prepared. It made full use of the chines, as well as elements from the previous designs, and was the sum of fifteen months of work.

  After a day and a half of work, the final drawing was completed. The long sheet of paper was presented to Johnson. Ben Rich, one of the engineers who worked on it told him, "Kelly, everything is now exactly where it should be — the engines, the inlets, the twin tails. This is probably as close to the best we can come up with." Johnson took the design and made repeated trips to CIA headquarters.[115]

  On July 20, 1959, President Eisenhower was again briefed on Gusto. At the meeting were Allen Dulles and Bissell from the CIA, Defense Secretary Neil McElroy, scientific advisers Dr. Killian and Dr. George Kistiakowsky, Gens. Thomas D. White and C. P. Cabell, and National Security Adviser Gordon Gray. The meeting lasted nearly an hour. Eisenhower gave approval for development to begin.[116]

  The Convair and Lockheed designs were submitted to a joint DOD-USAF-CIA selection board on August 20, 1959. The Convair design, called "Kingfisher," was a large delta-wing aircraft 79.5 feet long, with a wingspan of 56 feet and weighing 101,700 pounds. It was to be powered by two J65 jet engines and two Marquardt RJ59 ramjets. The jets would be used for takeoff and climb. Once up to speed, the ramjets would ignite and accelerate the plane to Mach 3.2. During flight, the Kingfisher would climb from an initial altitude of 85,000 up to 94,000 feet. The Convair aircraft had a range of 4,000 nautical miles.

  The final Lockheed design, the A-ll, was a single-seat aircraft. It had a long fuselage with a delta wing at the rear. The two J58 engines were midway out on the wings. The A-ll was 102 feet long and had a wingspan of 57 feet — a much larger aircraft than the Kingfisher. Yet its weight was 110,000 pounds, only marginally heavier. Its top speed was also Mach 3.2, and it had a range of 4,120 nautical miles. The A-ll had a better altitude capability — at the start of the cruise it would be at 84,500 feet, and this would increase to 97,600 feet. Both aircraft were to be ready in twenty-two months.[117]

  The Lockheed A-ll was selected on September 3. The Gusto code name was replaced by "Oxcart." Given the plane's extreme speed, the code name seemed to be "inspired perversity," as the official history put it. There was a subtle symbolism, however. Lockheed aircraft had long carried "star" or astronomical names — Orion, Vega, Sirius, Altair, Electra, Constellation, Starfire, Starfighter, and JetStar. In Europe, the constellation of the Big Dipper is often called a wagon — or an oxcart.

  OXCART

  Once Lockheed was selected, the CIA gave approval for a four-month series of aerodynamic and structural tests, engineering design, and construction of a full-scale A-ll mock-up.[118] The mock-up was needed to test the aircraft's radar cross section. Due to the complexity of the problem, it was not possible to use subscale models. It was completed in November 1959, then was packed in a huge box and moved by road from Burbank to Groom Lake. The mock-up was then reassembled and mounted on a pylon. For the next eighteen months the mock-up was scanned by radar, while adjustments and modifications were made. This early work was successful, and the CIA gave approval on January 30, 1960, for production of twelve aircraft.[119]

  Extreme security measures, tighter even than for the U-2, were used to hide the program. Because knowledge of Lockheed's involvement would create speculation, money to subcontractors was paid through "front" companies. Once the parts were completed, they would be shipped to warehouses, also rented to front companies. The parts would then be sent to Burbank. Few, if any, of the subcontractors knew what the parts were for.

  Ironically, some drawings were deliberately not classified; the assumption was that if they were stamped "Secret," people would take an interest.

  Just over three months after the Oxcart program started, Powers's U-2 was shot down. It was clear to Eisenhower that the United States would never again be able to make overflights of the Soviet Union. This also brought into question the future of Oxcart. The president seemed undecided, saying at one point that he was not sure if it would be best to end development, or if so much had been invested that the United States should capitalize on the effort by carrying it through. In the latter case, the program should be continued, although at a low priority, for use by the air force rather than the CIA. He asked CIA director Dulles to meet with Defense Secretary Thomas S. Gates and Maurice Stans, director of the Bureau of the Budget, to make a recommendation.[120]

  A new challenger appeared in the late summer. On August 19, the recovery capsule from the Discoverer 14 reconnaissance
satellite was caught in midair by a C-119 aircraft. This ended eighteen months of launch failures, tumbling satellites, and lost capsules. More important, the capsule carried a twenty-pound roll of film, covering 1 million square miles of the Soviet Union. This one mission provided more coverage than the twenty-four U-2 overflights together had accomplished.[121] More Discoverer satellites were launched and, within a year, they showed there was no missile gap: taken together, Soviet ICBM, submarine-launched missiles, and bomber forces were a fraction of the U.S. total. Satellites could cover the whole of the Soviet Union, without the political risks of aircraft overflights.

  Ultimately, Oxcart was seen as needed and was continued under CIA control. Satellites would be restricted to coverage of the Soviet Union for the foreseeable future. It would also be many years before a satellite camera had the resolution of the U-2's B camera. If the USSR was off limits for the U-2, it could still provide coverage of Communist China, Cuba, Vietnam, or the Mideast. In a few years, however, these areas could no longer be overflown with impunity. The Chinese already had SA-2 SAMs, and other countries would have them by the early and mid-1960s. The Oxcart would soon be needed to conduct overflights of even Third-World countries.

  INITIAL DEVELOPMENT

  Once the future of Oxcart was resolved, the initial development work continued. Temperature affected every aspect of the Oxcart's design. Even though the plane would be flying at the edge of space, friction would raise the skin temperature to over 500 degrees F. The coolest part of the engine, the inlet, reached 800 degrees F. The afterburner section would reach 3,200 degrees F.[122] The plane would have to be built of stainless steel or titanium.

  Stainless steel honeycomb was being used in the Mach 3 XB-70, then under development, but Johnson rejected this when he saw the production problems it entailed. The honeycomb had to be produced in a clean room, under sterile conditions. The Skunk Works motto was "KISS" (Keep It Simple, Stupid). Stainless steel was too complicated and was likely to cause problems.

  Johnson decided to use heat-treated B-120 titanium alloy. This was still a major step into the unknown. Although it had been used in aircraft before, nobody had ever tried to build an entire airframe out of the material. Even drilling a hole was a problem, due to titanium's extreme hardness. Drills would be worn out after only seventeen holes. A special West German drill was found that could drill 150 holes before needing resharpening.

  Before beginning production, Johnson decided to build a sample of the wing structure and nose section. When the wing structure was put in the "hot box," to simulate the high temperatures, it literally wrinkled. The solution was to put corrugations in the wing skin. At high temperatures, the corrugations only deepened slightly. Johnson was jokingly accused of building a Mach 3 Ford Trimotor (which also had a corrugated skin). The nose segment was used to study requirements for cooling the pilot, camera, and systems.[123]

  A continuing problem during development was the poor quality of the titanium. A full 80 percent was rejected; the material was so brittle that it would shatter like glass if dropped. This problem continued into 1961, until a group from CIA headquarters went to the Titanium Metals Corporation and briefed company officials about Oxcart. The supply soon became satisfactory.[124] Lockheed also established an extensive quality-control program.

  There were times, Johnson later recalled, "when I thought we were doing nothing but making test samples."[125]

  Sometimes the problems with titanium bordered on the bizarre. During heat tests, bolt heads would simply fall off after one or two runs. It was found that cadmium plating had flaked off the tools used to tighten the bolts. This was enough to "poison" the titanium, causing a spiderweb network of cracks to form. All cadmium-plated tools had to be thrown in a big vat that was boiling "like a witch's brew" to strip off the plating. It was also found that welds of wing panels done during the summer soon failed, while those made during the winter lasted indefinitely. Again, it was a chemical reaction. The parts were washed before welding, and in the summer, Burbank city water had chlorine added to reduce algae. Even an ordinary pencil was dangerous. A shop worker took a pencil and wrote some numbers on a piece of titanium; a week later, it was discovered the graphite had etched the metal.[126]

  Not simply the airframe, but every part would have to withstand temperatures higher than ever before endured by an aircraft. Johnson said later,

  "Everything on the aircraft, from rivets and fluids up through materials and power plants, had to be invented from scratch." All electrical connections were gold-plated, as gold retained its electrical conductivity better at high temperatures than copper or silver. The control cables were made of Elgiloy, a steel, chromium, and nickel alloy normally used in watch springs.[127] A hydraulic fluid was developed to withstand temperatures of 650 degrees F (150 degrees hotter than normal).[128]

  Fuel was a difficult problem. During subsonic cruise, such as during refueling, temperatures would drop to negative-90 degrees F. At Mach 3, the fuel would be heated to 285 degrees F. It would then be pumped through the afterburner exit flaps, acting like hydraulic fluid to control their position.

  This would raise its temperature to 600 degrees. The fuel would then be pumped into the J58 engine. Conventional fuel would boil and explode at such temperatures. The fuel developed was JP-7, also called LF-2A. It had a low vapor pressure; if a match was thrown into a pool of JP-7, the match would go out.[129]

  The internal stress caused by such heat affected the quartz glass window for the camera. The heat had to be even throughout the window, or there would be optical distortion. This one problem took three years and $2 million to solve. The quartz window was fused to its metal frame using high-frequency sound waves.

  The effect of these many problems was to delay the program and raise its cost.

  THE J58 PROPULSION SYSTEM

  Development of the J58 engines and their nacelles proved the most difficult problem. The J58 program was begun in late 1956 to power a navy attack plane with a dash speed of Mach 3. This speed would be maintained for only a few seconds. By late 1959, however, navy interest was fading, and it was decided to cancel the engine. The CIA requested the work be continued and the engine be modified for a continuous speed of Mach 3.2.

  A contract was issued for three ground test and three flight test engines.[130]

  With the many design changes needed to accommodate the extreme heat, virtually nothing remained of the original navy J58 engine when development was finished. To give one example, a standard ground test stand could not simulate the heat and altitude conditions required. Pratt and Whitney built a new test stand in which a J75 engine's exhaust was run through and around the J58. Speeds over Mach 3.6 and altitudes of 100,000 feet could be simulated.[131]

  For all its power, the J58 engine alone was not enough to drive the A-ll to Mach 3 by brute force. The nacelles were the key that opened the way to those speeds. They were not simply a place to put the engines, but an integral part of the propulsion system. Up to 1,600 mph, air would come in through the intake and a ring of centerbody bleed vents to feed the engine.

  As the A-ll approached Mach 3, the flow cycle would change. Air was now vented out the centerbody bleed vents. The effects were amazing — at Mach 3, a full 56 percent of the total thrust came from the intake. Another 27 percent came from the afterburner, while only 17 percent came from the J58 engine itself. In effect, the J58 was a flow inducer and the nacelles pushed the airplane.[132]

  It was a remarkable achievement, but years of development and flight testing would be needed before the system was reliable.

  AREA 51

  Once development began in earnest, the question became where to test the A-ll. Despite the success of the U-2 flight tests and the A-ll mock-up radar tests, Groom Lake was not initially considered. It was a "Wild West" outpost, with primitive facilities for only 150 people. The A-ll test program would require more than ten times that number. Groom Lake's five-thousand-foot asphalt runway was both too short and unable
to support the weight of the Oxcart. The fuel supply, hangar space, and shop space were all inadequate.

  Instead, ten air force bases scheduled for closure were examined. (This indicates the scale of operations envisioned.) The site had to be away from any cities and military or civilian airways to prevent sightings. It also had to have good weather, the necessary housing and fuel supplies, and an eighty-five-hundred-foot runway. None of the air force bases met the security requirements, although, for a time, Edwards Air Force Base was considered.

  In the end, Groom Lake was the only possibility. Plans were drawn up for the necessary facilities. As cover, the site was described as a radar test range. The remote location was explained as necessary to reduce interference from outside sources. Construction began in September 1960, several months after the CIA U-2 operation closed down. The first construction workers were housed in surplus trailers. A new water well was drilled, but the site still lacked anything but the basics.

  The first major construction work was the 8,500-foot runway. This was built between September 7 and November 15, 1960, and required some 25,000 yards of concrete. This was followed by construction of the fuel storage tanks. A-ll test operations would need 500,000 gallons of JP-7 per month. By early 1962, a tank farm with a storage capability of 1,320,000 gallons was completed. Three surplus navy hangars were obtained, moved to Groom Lake, then reassembled at the north end of the facility. The navy also provided over 100 surplus housing buildings. Additional warehouse and shop space was added. Repairs to the existing buildings from the U-2 days were also made. To provide access, 18 miles of highway leading into the site were resurfaced. This work was done on a two-shift basis and continued into mid-1964.

  The CIA ran into a legal problem with the construction work. Nevada law required that the names of all contractor personnel who stayed in the state for more than forty-eight hours be reported to state authorities. Listing the personnel and the companies working on the project would reveal the existence of Oxcart. The CIA general counsel discovered a loop-hole — government employees were exempt. Accordingly, all contractor personnel at Groom Lake received appointments as "government consultants." If any questions were raised, it could truthfully be said that only government employees worked at the site.