Facing changed circumstances in relations with the Soviet Union and in US satellite development, US policymakers and intelligence officials had to come to grips with how best to use the A-12 as it neared completion. Its intended purpose, replacing the U-2 in overflights of the Soviet Union, had become less and less likely well before the A-12 was operational. Soviet air defenses had advanced to the point that even an aircraft flying faster than a rifle bullet at the edge of space could be tracked. In any event, President Kennedy had stated publicly that the United States would not resume such missions. DCI McCone was determined to find a use for the aircraft—which he later described as “quite invulnerable except under miraculous circumstances” when it met design specifications. But he lost the argument then, as well as later, when making the case for deploying the A-12 to help determine whether the Soviets had constructed an antiballistic missile system around Leningrad. By 1965, moreover, the photoreconnaissance satellite programs had progressed to the point that manned flights over the Soviet Union were unnecessary to collect strategic intelligence.
The Cuban missile crisis of October 1962 drew attention to the OXCART program because of the threat the U-2 faced from Cuban air defenses. U-2s regularly overflew the island after nuclear missiles were discovered there in mid-October, but two weeks after the discovery, a U-2 was shot down by a Cuban surface-to-air missile. Regular high-altitude reconnaissance of Cuba might no longer be possible. The A-12 now had a potential mission, and achieving operational status became a priority. Because of continued difficulties in achieving design requirements with the J58 engine, however, the A‑12 would have to be flown only at up to Mach 2.8 at below 80,000 feet.
This risky program, codenamed SKYLARK, was accelerated during the summer of 1964, after Soviet Premier Nikita Khrushchev declared that after the US elections in November, U-2s flying over Cuba would be shot down. In August, Acting DCI Marshall Carter ordered that SKYLARK be operationally ready by 5 November 1964 in case Khrushchev carried out his threat. A detachment of five pilots and ground crew was organized to validate camera performance and qualify pilots for Mach 2.8 operations. They would have to go into action without the full complement of ECMs, as only one of the several devices planned would be available by the deadline, and Agency technical officers were certain that the Cubans would detect the flights and could shoot down the A-12s.
In the end, Khrushchev’s threat was bluster, and the A-12 never was used against Cuba. US officials were still discussing the possibility nearly two years later, however, and CIA officials regarded Cuban overflights as a potentially productive way to test the A-12’s ECMs in a hostile area where weather was a factor. Agency analysts judged that the Soviets most likely would react to the flights privately and in low key. The 303 Committee—the NSC group that reviewed sensitive intelligence operations—rejected the idea because it “would disturb the existing calm prevailing in that area of our foreign affairs." 
East Asia was the next area US leaders considered using the A-12. The People’s Republic of China (PRC) had successfully tested a nuclear device in October 1964, and US military activity in Vietnam was increasing. Overhead collection would be the most important method for monitoring the Chinese program and the military situation in Vietnam, but satellites did not have a quick reaction capability, and several U-2s and drones had been lost over China. US military and intelligence officials drew up a plan for flying OXCART aircraft out of Kadena Air Base on Okinawa under a program called BLACK SHIELD. The Pentagon made available nearly $4 million to provide support facilities on the island, which were to be ready by early fall 1965.
Meanwhile, North Vietnam was starting to deploy SAMs around Hanoi, and a concerned Secretary of Defense McNamara inquired in June 1965 about substituting A-12s for U-2s for reconnaissance over the North. CIA said that BLACK SHIELD missions could be flown over Vietnam as soon as operational performance requirements were achieved. With an overseas deployment looming, personnel at the A‑12 test site went all out to have the aircraft meet mission requirements by late 1965. Improvements came faster than expected.
In August, DCI Raborn, who replaced McCone in April 1965, notified President Johnson that an A-12 had successfully simulated an operational mission with two refuelings and three cruise legs. On each leg the aircraft reached its design cruising speed of Mach 3.1 at altitudes between 80,000 and 90,000 feet. The flight covered a total distance of 7,480 miles in just under five and a half hours; forty percent of that time was spent at cruising speed. Only three minor malfunctions occurred; significantly, none involved the air inlets and electrical systems or were related to high heat.
“The Bird Should Leave Its Nest”
Kelly Johnson’s firm managerial hand had gotten OXCART back on track. Four A-12s were selected for BLACK SHIELD, and final validation flights were conducted during the fall. During them, the A-12s flew faster, higher, and longer than ever before. On 12 November 1965, the CIA’s director of special activities in charge of the program wrote to the Agency’s director of reconnaissance that he was “very pleased to announce that, in my judgment, the A-12 aircraft, its technical intelligence sensors, and its operating detachment are operationally ready…. The detachment is manned, equipped, and highly trained…. The aircraft system is performing up to specifications with satisfying reliability and repeatability.” Because of “some as yet unexplainable phenomena at cruise conditions,” the A-12 could not fly as far as originally intended, but missions could be designed to take that deficiency into account. By 20 November, the validation flights were complete, and all the pilots were Mach 3 qualified. Two days later, Johnson told the Agency that “the time has come when the bird should leave its nest." 
Soon after, CIA’s Board of National Estimates (BNE) issued an assessment of the potential political implications of BLACK SHIELD. The Agency’s most senior analysts judged that the PRC would quickly track overflights of its territory but would not start a diplomatic controversy about them unless it shot down an aircraft. Doing so would occasion a major political and propaganda campaign, but “[w]e do not believe that OXCART missions, whether or not any aircraft came down inside China, would significantly affect Peiping’s broader calculations governing its policy toward the war in Vietnam.” North Vietnam, “already subjected to heavy US air attack and reconnaissance…would attach little extra significance to the OXCART operation.” Lastly, through various sources, the Soviet Union would soon get a fairly complete picture of the scope of BLACK SHIELD but “would probably take no action and make no representations on the matter." 
Analyses such as the BNE’s informed the approval process for proposed OXCART missions. The steps were the same as for U-2 flights: an NSC-level recommendation and a presidential authorization. After the A-12 passed its final tests, in early December the 303 Committee ordered the development and maintenance of a quick-reaction capability by 1 January 1966, with deployment to Okinawa 21 days after the president issued his go order.
Then, nothing happened for more than a year. The 303 Committee approved none of CIA’s five deployment requests, submitted with support in most instances from the Joint Chiefs of Staff and the PFIAB. Community analysts continued to believe the Chinese, North Vietnamese, or Soviets would not react publicly and belligerently to the missions. Siding with top State and Defense officials, however, the committee did not believe the intelligence requirements at the time—including warning of Chinese intervention in the Vietnam war—were so urgent as to justify the political risk of basing the detachment at Okinawa or revealing some of the A‑12’s capabilities to hostile nations.
In addition, some reluctance to use the A-12 was related to the discussion that had already begun about phasing out the CIA program. In mid-August 1966, President Johnson listened to the divergent views and upheld the 303 Committee’s decision not to fly actual missions for the time being.
Biding Time, Sharpening Procedures
During these months OXCART personnel worked on refining mission plans and flight tactics, testing the aircraft and systems, training, and preparing the forward base at Kadena. The delay was beneficial. Even though the A-12 had been declared operationally ready, important components in the propulsion system still needed correction. More efficient procedures reduced the time required to go from mission notification to deployment from 21 to 15 days. Six operationally configured aircraft were constantly training and engaging in operational flight simulations.
In October 1966, one week after its first flight, Article 127 flew for seven hours and 40 minutes, the longest time in air so far. Two months later, Lockheed test pilot Bill Parks completed an impressive demonstration of the A-12’s capabilities by flying 10,198 miles in six hours at an average speed of 1,659 mph (including slowdowns for refueling)—setting a speed and distance record unattainable by any other aircraft. By mid-February 1967, 2,299 test and training flights had been flown over 3,628 hours, with more than 332 of those at Mach 3 or higher.
The first fatality of the OXCART program occurred on 5 January 1967, when Article 125 crashed, killing CIA pilot Walter Ray. Because of a faulty fuel gauge and related electrical equipment problems, the aircraft ran out of fuel while on its descent to the test site. Ray ejected at between 30,000 and 35,000 feet but did not separate from the seat. That kept the parachutes from deploying, and he fell to earth, dying on impact. To protect the security of the A-12 program, the Air Force informed the media that an SR-71 was missing and presumed down, and identified the pilot as a civilian. Like the three crashes that preceded it, Ray’s involved a problem inherent in any new aircraft—a malfunction of a part specifically designed and built for it. None of the four incidents occurred while the A-12 was being subjected to the unprecedented rigors of design speeds and altitudes.
Missions Begin: Spying on the Enemy
This image of Hanoi area was taken during the fourth mission, on 30 June 1967.
OXCART’s first mission over Southeast Asia, 31 May 1967. With pilot Vojvodich in the cockpit, Article 131 refueled three times during its 3 hour 39 minute flight.
By early 1967, the Johnson administration was growing anxious that the North Vietnamese could deploy surface-to-surface missiles (SSM) targeted at the South without being detected. When the president asked for a collection proposal, CIA suggested that the A-12 be used, noting that its camera was better than those on drones or the U-2, and that it was much less vulnerable than those platforms and more versatile than the CORONA satellites. DCI Helms brought up the idea at a luncheon with the president on 16 May and got his approval. The Agency put the BLACK SHIELD deployment plan into effect later that day.
On 17 May, the airlift of personnel and equipment to Kadena began, and Articles 131, 127, and 129, flown by Vojvodich, Layton, and Weeks, arrived between 22 and 27 May. The first two flew non-stop from Nevada to Kadena; the third diverted at Wake Island to correct an equipment malfunction and finished the trip the next day. The unit, which at its inception had been designated for security purposes as the 1129th US Air Force Special Activities Squadron (SAS), Detachment 1, comprised three A-12s, six pilots (three deployed at a time; later two), and over 250 support personnel. Its commander was Col. Hugh “Slip” Slater, who had worked with CIA on the U-2 program and at the OXCART test site. The 1129th SAS was ready for operations by the 29th. The call came the next day to fly the first mission on the 31stover North Vietnam.
Piloted by Vojvodich (Layton was the secondary, and Weeks was the backup), Article 131 took off just before 1100 local time in a torrential downpour. The A-12 had never operated in heavy rain before, but the weather over the target area was forecast to be satisfactory, so the flight went ahead. It lasted three hours and 39 minutes and was flown at Mach 3.1 at 80,000 feet. Vojvodich crossed the coast of North Vietnam at 1014 local time (Vietnam is two hours ahead of Okinawa), flew the planned single-pass route in less than nine minutes, refueled over Thailand, exited near the Demilitarized Zone (DMZ) at 1122, and touched down at Kadena in the rain at 1233 local time.
OXCART’s first mission over Southeast Asia, 31 May 1967. With pilot Vojvodich in the cockpit, Article 131 refueled three times during its 3 hour 39 minute flight.
The mission was a success, photographing 70 of the 190 known SAM sites and nine other priority targets, including an airfield, a military training area, an army barracks, and the port at Haiphong. No SSM facilities were located. Contrary to some published accounts, neither Chinese nor North Vietnamese radar tracked the aircraft nor did North Vietnam fire any missiles at it. Those hostile reactions did not occur until the third and 16th missions, respectively.
Through 6 May 1968—the date of what would become the last flight—the A-12 pilots at Kadena flew 29 missions out of 58 they were put on alert to perform: 24 over North Vietnam; two over Cambodia, Laos, and the DMZ; and three over North Korea. The flights were distributed among the pilots: Collins and Layton had six, Vojvodich and Weeks got five, Murray did four, and Sullivan was on three. The aircraft were flown at between Mach 3.1 and 3.2 and a bit above 80,000 feet. At that height, above the jet stream, air turbulence was minimal, and the curvature of the earth showed beneath the black, star-flecked sky.
The A-12s’ aeronautical components and photographic systems proved very reliable. Twenty-seven of the sorties were judged successful, based on the quality of photography returned; two were deemed partially successful or unsuccessful due to cloud cover or a camera malfunction. One mission had to be cut short after one pass because of an engine problem. None of the 29 cancelled alerts were the result of mechanical concerns; bad weather caused all but three, which were due to operational decisions. The A-12s were so fast that they typically spent only about 12.5 minutes over North Vietnam on a single-pass mission and 21.5 on a double-pass route.
Project headquarters in the Washington DC area planned and directed all the A-12 missions. Their preparation followed this procedure: Each day at 1600 local time a mission alert briefing took place. If the weather forecast—the key variable in deciding whether to go ahead or cancel the sorties—seemed favorable, Kadena was alerted and given a flight profile about 28 to 30 hours before takeoff. The primary and back-up aircraft and pilots were selected. The A-12s—painted black and bearing no markings other than red tail numbers that were changed every mission—got thorough inspections and servicing, all systems were checked, and the cameras were loaded into the bays. On the evening before the day of the flight, the pilots received a detailed briefing of the route. Twelve hours before takeoff (H minus 12), headquarters again reviewed the weather over the target. If it was still favorable, preflight procedures continued.
On the morning of the flight, the pilots got a final briefing. The aircraft’s condition was reported, weather forecasts were reviewed, and changes in the mission profile and relevant intelligence was communicated. At H minus 2, headquarters issued a “go/no-go” decision. At this point the weather forecast also had to be good for the refueling areas. If the mission was still on, the primary pilot received a medical examination, suited up, and squeezed himself into the aircraft. If any malfunctions developed, the back-up would be ready to fly one hour later. This proved necessary only once. On the second mission on 10 June 1967, the primary A‑12 lost a fillet panel during refueling and returned to base, and the back-up completed the mission. On most BLACK SHIELD flights, the A-12s were airborne about four hours. The shortest complete mission in Southeast Asia lasted just over 3.5 hours; the longest took nearly 5.5 hours. The aircraft took on fuel two or three times, depending on the planned route, on each operational flight: once, soon after takeoff south of Okinawa, and once over Thailand for each pass it would make over the target area before it returned to Kadena.
After the A-12s landed, the camera film was removed from the aircraft, boxed, and sent by courier plane to a processing facility. At first the film was developed at the Eastman Kodak plant in Rochester, New York. That trip took too long for US military commanders who wanted the intelligence more quickly. By late summer, processing was shifted to an Air Force center in Japan, and the photography could be available to the US military in Vietnam within 24 hours after a mission was completed.
Less than two months into BLACK SHIELD, analysts had enough evidence to conclude that North Vietnam had never deployed SSMs. By the end of 1967, the A-12 had collected clear, interpretable photography of all of North Vietnam except for a small area along the border with the PRC. The BLACK SHIELD missions provided valuable imagery of SAM sites, airfields and naval bases, ports, roads, and railroads, industrial facilities, power plants, and supply depots. Military planners and photo interpreters used the information to develop air and air defense order of battle estimates, assess bomb damage, and develop flight routes and target sets for bombing runs, enabling US pilots to accomplish their missions more effectively and in greater safety. Analysis of photography of the DMZ gave insights into North Vietnamese infiltration and supply routes and North Vietnamese and Viet Cong troop deployments.
President Johnson’s national security adviser, Walt Rostow, recounted that the A-12 missions (along with those of the SR-71) “were invaluable to the president.” Without them, he “would never have allowed any tactical air operations in the North because he was extremely sensitive…to the possibilities of a bomb accidentally hitting a Chinese or Russian ship while it was unloading in the harbor, and he also was determined to keep civilian damage and casualties to a minimum.” Johnson “usually chose the targets personally and insisted on approving each and every raid into the North…. Before signing off on a mission he calculated in his own mind whether the anticipated losses were worth the anticipated gains.” The A-12 and SR-71 photographs “were the decisive factors in helping him to make up his mind."
Under Fire over Vietnam
North Vietnam fired SAMs at BLACK SHIELD A-12s three times but caused damage only once. The first attempted shootdown occurred on the 16th mission on 28 October 1967. Flown by Dennis Sullivan, the aircraft was on its second pass, approaching Hanoi from the west, when an SA-2 was launched at it. Photographs taken during the mission show missile smoke above the SAM site and the missile and its contrail, heading down and away from the aircraft. The A-12’s ECMs worked well, and the SAM, which was fired too late, was never a threat.
The second incident, two days later, on the 18th mission, was the closest an OXCART aircraft ever came to being shot down. Sullivan again was the pilot. On the first pass between Hanoi and Haiphong, radar tracking detected two SAM sites preparing to launch, but neither did. On the second pass toward Hanoi and Haiphong from the west, at least six missiles were fired from sites around the capital. The A-12 was flying at Mach 3.1 at 84,000 feet. Looking out the rear-view periscope, Sullivan reported seeing six vapor trails go up to about 90,000 feet behind the aircraft, arc over, and begin converging on it. He saw four missiles—one as close as 100 to 200 yards away—and three detonations behind the A-12. Six missile contrails appeared on mission photography.
A post-flight inspection at Kadena found that a piece of metal, probably debris from an exploded missile, had penetrated the lower right wing and lodged near the fuel tank. A BLACK SHIELD officer at Kadena noted that the A-12 pilots were “showing considerable anxiety about overflying this area before we get some answers.” Helms ordered that missions be temporarily suspended. None was flown until 8 December. It and the following one two days later photographed the Cambodia-Laos-South Vietnam triborder area and were not sent over the North.
Sorties over North Vietnam resumed on 15 December and continued until 8 March 1968—the next-to-last BLACK SHIELD flight. The first two flights took different paths than the Hanoi-Haiphong route followed by the A-12s that were shot at in late October. Another SAM was fired on mission 23 on 4 January 1968; that aircraft took the same route as those that had been attacked. The missile, fired on the second pass like the others, was captured on photography from launch to detonation, well over a mile from the aircraft. Two of the next three flights over North Vietnam came in from the south rather than the east, and all three stayed farther away from Hanoi and Haiphong than those that had been shot at. The general times when these flights were made did not change despite the SAM attacks; all crossed into North Vietnamese territory in the late morning.
Looking for the Pueblo
The North Korean seizure of the US Navy ship Pueblo while it was on a SIGINT mission in international waters on 23 January 1968 enabled the A-12 to demonstrate its superiority as a quick-reaction collection platform. Although the US military had indicated its interest in BLACK SHIELD overflights of North Korea even before the incident, the Department of State had opposed them, and none was planned when the Pueblo was captured. Walt Rostow remembered that “[t]he whole country was up in arms over this incident. The president was considering using airpower to hit them [the North Koreans] hard and try to shake our crewmen loose. But when we cooled down, we had to suck in our gut and hold back until we were sure about the situation.”
Helms urged use of the A-12 to find the missing ship. Johnson was reluctant at first to offer such a “tempting target” but was assured that the aircraft “could photograph the whole of North Korea, from the DMZ to the Yalu River, in less than 10 minutes, and probably do so unobserved by air defense radar. Which is precisely what happened."
On 24 January the Pueblo advisory group—comprising senior officials from the White House, the Departments of Defense and State, and CIA—had Helms draw up a reconnaissance plan that included A-12s. President Johnson approved their use later that day. On the 26th, Jack Weeks flew a three-pass mission over the southern part of North Korea and the Demilitarized Zone. The purpose was to determine whether Pyongyang, which claimed it had caught the United States spying inside its territorial waters, was mobilizing for hostilities. Chinese radar tracked the A-12, but no missiles were fired during the highly successful mission.
Substantial intelligence was acquired on North Korea’s armed forces; no signs of a military reaction were detected; and the Pueblo, apparently undamaged, was found in a small bay north of Wonsan accompanied by two patrol boats. “So we had to abandon any plans to hit them with airpower,” according to Rostow. “All that would accomplish would be to kill a lot of people, including our own.” But the A-12’s photographs “provided proof that our ship and our men were being held. The Koreans couldn’t lie about that, and we immediately began negotiations to get them back." After difficult and protracted discussions, North Korea released the surviving crewmembers 11 months later.
The US military wanted a second overflight of North Korea, but the Pueblo advisory group decided not to recommend any more right away because the “excellent” photography taken on the 26th, along with other information, was deemed sufficient to answer the crucial questions. By mid-February, however, the need returned. After the Department of State accepted assurances that it was highly unlikely the A‑12 would come down in hostile territory if something went wrong, the 303 Committee approved two more missions over the peninsula. They were flown on 19 February and 6 May. On the first sortie, scattered clouds concealed the area where the Pueblo had been spotted. (The ship had been moved by then.) The second flight—the last A-12 mission, as it turned out—was piloted by Jack Layton. Like the other missions over North Korea, it found no sign of a military buildup.