B-52 Stratofortress

by Bill Yenne

  In January 1964, a B-52H piloted by Boeing test pilot Chuck Fisher lost its vertical stabilizer in severe turbulence over the Rockies. Amazingly, Fisher managed to land safely. USAF

  Nearly a year later, a three-man Boeing crew suffered the loss of a vertical stabilizer on a test flight out of the company’s facility in Wichita, but managed to save the aircraft. The January 10, 1964, mission had involved cruising at an altitude of 500 feet over the Colorado Rockies, but when the B-52H encountered moderate turbulence, pilot Chuck Fisher climbed to 14,300 feet, where he briefly found smooth air. However, rough turbulence suddenly rocked the ship. It was jabbed from the side severely, then tossed up and down. The crew noted high vertical g-forces and lateral motion of the airplane.

  The air crews of Operation Power Flite, led by Maj. Gen. Archie Old, Jr., make their triumphant return to March AFB on January 18, 1957, to be greeted by General LeMay and others. USAF

  As Fisher recalled, “I gave orders to prepare to abandon the airplane, because I didn’t think we were going to keep it together. We didn’t know what was damaged, but control was difficult. We cut our speed to 225 knots, and dropped to about 5,000 feet. Everybody was ready, should the need come to leave the ship. We figured we’d put a little more altitude between us and the ground, so we climbed to 16,000 feet very slowly. We kept trying to figure out the reason for our control problem. We had all eight engines, and all leading edges, but the plane would suddenly pitch or buck in response to control. When this happened, control was very marginal and we didn’t hold out much hope for getting it in a landable condition.”

  Fisher attempted to return to Wichita, but the pilot of a Boeing chase plane who met him reported the loss of 90 percent of the vertical tail. Because of weather at Wichita and the large population in the area, Fisher diverted to Blytheville AFB in Arkansas, shadowed by several chase planes, including a KC-135 full of Boeing engineers. Six hours after the incident occurred, Fisher and his crew successfully landed the damaged B-52H, demonstrating that the aircraft was at least theoretically flyable in this condition.

  This also provided Boeing with information vital for retrofitting the Stratofortress fleet to head off later problems. This project, initiated at Boeing’s Wichita facility with the Load Alleviation and Mode Stabilization (LAMS) study, led to development of an advanced flight control system.

  Just three days after Fisher’s accident, though, a similar incident did not end so happily. A B-52D returning to Georgia from a Chrome Dome deployment to Europe lost its vertical stabilizer in heavy turbulence over Pennsylvania and crashed into Savage Mountain near Cumberland, Maryland. Two of the four crewmembers who successfully ejected died of hypothermia before being rescued. According to a Defense Department summary, the two Mk 53 (later B53) nuclear weapons that had been aboard the bomber were found “relatively intact in the middle of the wreckage.”

  In the latter part of the decade, two well-publicized Stratofortress Broken Arrow incidents occurred overseas, in Spain and Greenland. Often considered to be the most serious of such accidents, they are also the only two events involving aircraft of any type that were on Time magazine’s 2009 and 2011 “Worst Nuclear Disasters” lists.

  The first of these occurred on January 17, 1966, with a B-52G based at Seymour-Johnson AFB in North Carolina that was on a Chrome Dome deployment. This aircraft collided with a KC-135 Stratotanker during a refueling operation at 31,000 feet over the Mediterranean Sea off the coast of Spain, near the fishing village of Palomares. The fuel load of the tanker exploded, killing all four crew members, while the Stratofortress broke up, killing three of the seven men aboard. Three of the four Mk 28 (later B28) thermonuclear weapons aboard the aircraft struck land near Palomares. According to SAC, two of these “underwent non-nuclear TNT-type explosions on impact,” when they crashed on land, releasing “some radioactive material,” specifically plutonium.

  The fourth weapon fell into the Mediterranean, and was the subject of an extensive search involving a flotilla of U.S. Navy ships, including the recently commissioned deep-water submersible Alvin. The weapon was found unexploded on a 70-degree slope at a depth of 2,550 feet on March 17, but it took two attempts before it was successfully recovered on April 7.

  B-52s in the SAC Inventory: Buildup and Peak Strength Era

  Numbers exclude aircraft not assigned to SAC

  On January 21, 1968, two years after Palomares, another B-52G crashed, this time on sea ice in North Star Bay, Greenland. The aircraft, assigned to the 380th Strategic Bombardment Wing at Plattsburgh AFB in New York, experienced a cabin fire while on an Operation Hard Head patrol over Baffin Bay and was attempting to make an emergency landing at Thule AB in Greenland. Six of the seven crew members managed to eject successfully, but the four Mk 28s aboard were scattered in the crash, and there were extensive radiation leaks.

  The Project Crested Ice cleanup operation began immediately in an attempt to contain all of the nuclear material dispersed in a 3-square-mile debris field. This was complicated by high winds and bitterly cold temperatures, as well as the fact that the fire that consumed the Stratofortress had melted some of the ice, causing some wreckage and other material to go into the ocean. Most, though not all, of the bomb components had been recovered when Crested Ice was terminated in September.

  The Thule incident created political embarrassment in Denmark, which owns Greenland, because the country had earlier declared itself a nuclear-free zone. This furor in international relations caused by both Palomares and Thule accelerated a decision by the United States to stand down both Chrome Dome and Hard Head operations. The exact nature of the Hard Head missions, meanwhile, would not be revealed until much later.

  Stand-Off Missiles, the First Generation

  The Stratofortress had been conceived at a time when the primary method by which a bomber delivered ordnance was to drop bombs. During World War II, aircraft had been adapted to fire short-range rockets, which were mostly unguided and mostly used against ground targets. The use of long-range, air-dropped missiles against strategic targets was the subject of various studies in the 1940s, but it was not until the late 1950s that the U.S. Air Force seriously planned to use the Stratofortress to carry such missiles.

  The catalyst for this change of tactics was the growing threat presented by an increasingly sophisticated Soviet air defense system. Originally, it was assumed that highflying postwar bombers would operate at altitudes that would make them immune to antiaircraft fire. However, by the mid-1950s, advances in surface-to-air missiles caused strategic planners on both sides of the Iron Curtain to do some rethinking.

  Strategic missiles carried by bombers are called stand-off weapons for a good reason. They allow the bomber to release its ordnance a safe distance from a heavily defended target, then turn and flee. They also allow the bomber to be farther from the blast of its own thermonuclear weapon. A variety of missiles were considered and tested. For example, the Bell B-63 (later GAM-63) Rascal was test launched from the B-47. The first one to be widely deployed as B-52 armament was the North American GAM-77 (later AGM-28) Hound Dog air-launched cruise missile.

  The Air Force initiated the Hound Dog project in early 1959 with the first guided, air-launched flight test of the XGAM-77 prototype coming in August, and deliveries of operational missiles by year end. Inertially guided and turbojet-propelled, each missile carried a W28 thermonuclear warhead. They were 42 feet 6 inches long and weighed 10,000 pounds.

  An artist’s conception of an AGM-28 Hound Dog, marked with the SAC shield, headed for its target. A Stratofortress can be seen banking away in the distance.

  A B-52G armed with two AGM-28 Hound Dogs on its underwing pylons. For many years after the Hound Dog was introduced, these pylons were referred to as AGM-28 pylons, whether they held other types of missiles or gravity bombs. The pylons could each accommodate a dozen Mk 82 bombs and did so during the Vietnam War. USAF

  A B-52G armed with four XGAM-87A (later AGM-48) Skybolts. The missile represented a st
ate of the art in long range stand-off weaponry that was not to be matched again for two decades with the AGM-86. USAF

  A B-52G with a GAM-72 (later ADM-20) Quail in the foreground, as seen in June 1960. USAF

  Hound Dogs could be launched nearly 800 miles from the target, allowing the B-52 to turn for home before they struck the target. Hound Dogs deployed quickly, reaching a peak inventory of 593 AGM-28As in service with SAC by 1963. Eventually, nearly 500 missiles were modified to have a smaller radar cross section and redesignated as the AGM-28B.

  Many B-52Gs, as well as some examples of all models back to the B-52C, were retrofitted to carry the Hound Dog. Such modifications included strengthening the wing and adding underwing pylons between the inboard engine and the fuselage so that each bomber could carry a pair of Hound Dogs.

  Simultaneous with the development of the Hound Dog was that of the McDonnell GAM-72 (later ADM-20) Quail, a missile whose function was to act as a decoy by emulating the Stratofortress on radar. Though it had the same radar signature as a B-52 bomber, it actually resembled a large winged refrigerator in size and shape. The Quail’s autopilot could be preprogrammed for a flight path simulating that of a bomber, and an infrared device aboard mimicked the heat signature of a bomber’s engines.

  In the early 1950s, the U.S. Air Force had started looking into developing self-propelled decoys that could be carried aboard bombers such as the B-36 and B-47, which were tasked potentially with flying missions into Soviet air space. Of the decoys designed, only the Quail was deployed. The first test flight of a powered Quail occurred in August 1958 after glide tests beginning late in 1957.

  The Quail entered service with SAC units in early 1961, being flown mainly aboard B-52Gs and B-52Hs. With their wings folded, eight Quails could be accommodated in a B-52 bomb bay, though operationally, the bombers carried fewer. Redesignated as ADM-20 in 1963, more than five hundred Quails were delivered. They remained in service until 1978, by which time radar technology had improved to the point where the Soviets could distinguish real bombers from Quails.

  Other steps that were taken in the 1950s to address the Soviet air defense threat included both tactics and electronics. In considering the former, mission planners instituted low-level attack scenarios in which the bombers would fly under Soviet radar before launching their missiles. Indeed, the intended launch scenario for the Hound Dog was at low level.

  As noted earlier, terrain avoidance systems were introduced as standard in the B-52E and B-52F, retrofitted into earlier B-52s, and included in later models as they were delivered. Strengthened airframes were also part of the preparation for low-level operations, as were electronic countermeasures (ECM) packages designed to protect the bombers from Soviet missiles, early warning radar, and ground control intercept radar.

  Even as the Hound Dog was becoming operational, the U.S. Air Force had even higher hopes for a strategic missile with nearly twice the range. The Douglas GAM-87 (later AGM-48) Skybolt was developed in the late 1950s at a time when ICBMs were still liquid-fueled, cumbersome to launch, and not yet fully reliable. The Skybolt was powered by a solid-fuel rocket engine, weighed 11,000 pounds, and, at 38 feet and 3 inches, was more compact than a Hound Dog. It was designed so that four could be carried by a single Stratofortress, and it was once intended that the Skybolt would be the principal armament of the B-52H.

  An August 1961 view of a Douglas XGAM-87A (later AGM-48) Skybolt on its hydraulic loading trailer, parked next to a Stratofortress.

  Frames from a grainy 16mm film of an XGAM-87A (later AGM-48) Skybolt being test fired from a Stratofortress. This may be film of the first successful launch on December 19, 1962. Ironically, this was the same day as the program’s termination. USAF

  As the Skybolt was being developed for the U.S. Air Force and showing great promise as a Stratofortress-launched weapon, it also attracted the attention of the British. Seeking to maintain their own independent, state-of-the art nuclear strike capability, the British agreed in May 1960 to adopt the Skybolt and hang it on their Avro Vulcan bombers. In so doing, they abandoned a plan to improve Avro’s own Blue Steel stand-off missile.

  The British commitment notwithstanding, Defense Secretary Robert McNamara had grown cool on the Skybolt concept because of unsuccessful test launches and the promise of the upcoming Minuteman solid-fuel ICBM. This set the stage for a headline-grabbing political crisis that would nearly bring down the British government and that damaged Anglo-American relations for years.

  The Skybolt was first successfully air launched on December 19, 1962—the same day that McNamara chose to cancel the program. The night before, at a meeting in the Bahamas, President John F. Kennedy had told British Prime Minister Harold MacMillan that the ax was about to fall. As a consolation, Kennedy allowed MacMillan to acquire the Polaris SLBM for the Royal Navy’s submarines, which was arguably a better operational choice for the British.

  For the Strategic Air Command, this meant that the service life of the Hound Dog would be extended until 1977. It would be two decades before the AGM-86 Air-Launched Cruise Missile (ALCM) finally filled the gap left by the Skybolt cancellation.

  Senior Bowl

  Kept in strictest secrecy at the time, two B-52Hs were configured in the late 1960s to carry unmanned reconnaissance aircraft on their underwing pylons. This was the Mach-3-plus Lockheed D-21 drone, which was originally designed to be launched from the M-21 “Mothership” variant of the Mach-3-plus Lockheed SR-71 Blackbird manned reconnaissance aircraft. Like the Blackbird, the D-21 was conceived by Kelly Johnson’s Advanced Research Projects department at Lockheed, known as the Skunk Works. The idea for each was an aircraft too fast for any other aircraft to catch and that could therefore operate with impunity in any hostile airspace.

  Powered by Marquardt RJ43 ramjet engines, the D-21 was just a few inches longer than a Hound Dog at 42 feet 10 inches long, with a wingspan of 19 feet. Its range once launched from the mothership would exceed 3,000 miles.

  A B-52H carrying a pair of Mach-3-plus Lockheed D-21B reconnaissance drones. This configuration was used operationally between November 1969 and March 1971. USAF

  The D-21 was designed to be recovered by parachute after it ejected a module containing sensor gear, its reconnaissance camera, and film exposed on its mission. First launched in March 1966, the D-21 suffered a failure on its fourth flight that resulted in the loss of both drone and mothership. In the wake of this incident, Kelly Johnson proposed that they switch to using a B-52H as the mothership. The launch would be at subsonic speeds, but the D-21 could be under the mothership, and hence it could be dropped rather than having to be launched from the top of another aircraft. Under the operational name Senior Bowl, the first successful launch of a D-21 from a B-52H occurred in June 1968.

  Between November 1969 and March 1971, B-52Hs flying out of Andersen AFB on Guam launched four D-21s in unsuccessful attempts to observe the Chinese nuclear test site at Lop Nor. These failures, combined with advances in satellite technology, resulted in the termination of Senior Bowl, though its existence was not revealed until 1977.

  Balls Eight

  During the 1950s, aviation technology was moving by leaps and bounds. Aircraft were establishing new speed and altitude records by substantial margins and doing so routinely. In the United States, Edwards AFB in California was the center of the action during the heyday of the quest for higher and faster. By 1959, North American Aviation had developed the ultimate expression of the era, the X-15. This aircraft was destined to set records that still stand today. It is still the fastest powered, winged, and manned aircraft ever flown. (The Space Shuttle reentered the atmosphere at higher speeds, but it was unpowered at this stage.)

  The first of three X-15 aircraft was originally delivered in U.S. Air Force markings, but the program was managed jointly by the U.S. Air Force and NASA, with pilots from both entities, as well as the U.S. Navy, participating in the program’s 199 flights. Like other manned and unmanned research aircraft before and since,
the X-15 was designed to be air-launched rather than runway-launched.

  As a carrier aircraft, the B-52 Stratofortress was uniquely suited to the task. It had the payload capacity, and the high wing meant that an aircraft could be accommodated on a pylon beneath the wing, as were the unmanned Hound Dog or Skybolt.

  The X-15 was 50 feet 9 inches long and weighed around 17 tons when launched, triple the weight of the Hound Dog or Skybolt. Therefore, the Stratofortress was the only aircraft that could realistically function in this role, and even then a 48-square-foot section of the right wing flap had to be cut out to accommodate the X-15 tail.

  The X-24A lifting-body research aircraft begins its rocket-powered flight after being launched from the wing of NASA’s NB-52B mothership during a 1970 research flight. NASA

  One of three X-15 rocket-powered research aircraft being carried aloft under the wing of its NB-52A mothership. The X-15 was air-launched from the Stratofortress so the rocket plane would have enough fuel to reach its high speed and altitude test points. NASA

  High-altitude contrails frame the NB-52A mothership as it carries the X-15 aloft for Air Force Major Robert White’s first X-15 flight in April 1960. NASA

  NASA’s NB-52B lifts off on August 1, 1997, carrying the X-38 lifting body, then being considered as a prototype for an emergency crew return vehicle for the International Space Station. NASA