16 November 2006

Flightdeck Friday - The Project Valour-IT Challenge

(Ed: See "Catching Up" for the Valour-IT reference)

The B-52 Stratofortress

The B-52 (aka ‘aluminum overcast’ or BUFF – Big Ugly Fat Fellow (or cruder term for the 2nd ‘F’...) has been flying for over 50 years now and by all rights, looks to remain in the inventory until around 2040. Volumes have been (and undoubtedly will be) written of the BUFF’s exploits, from forming one of the three legs of the strategic triad, to conventional attack in Vietnam and the Gulf, to maritime support and aerospace research. For our purposes here we are going to skip some of the more well known exploits and instead touch on some less familiar aspects and exploits. We begin, at the beginning (of course)

The BUFFs’ Beginnings

Even as it was entering frontline service, the B-36 was already on the threshold of obsolescence in the post-WWII years. In July of 1948 Boeing designers were penning what eventually would become the XB-52. As originally conceived, the XB-52 had straight wings and would be powered by six Wright T-35 turboprops. As the design morphed, the wings became swept and eventually the turboprops replaced by eight of the new Pratt & Whitney J57-P-3 turbojets. This final design was approved by the Air Force in October 1948 and on 29 November 1951; the XB-52 was rolled out from Boeing’s Wichita facility (under tarps) and soon would be joined by a stablemate, the YB-52. Owing to equipment installation issues, the YB-52 would be the first to fly on 15 April 1952 and the XB-52 on 2 Oct 1952. The production model, the B-52A, was ordered even before the prototypes flew and saw several significant changes – uprated J57’s, a different cockpit configuration and the addition of 3 more feet just aft of the cockpit. The bulk of the versions that would outfit SAC began with the B-52B model, followed by the archetypical B-52C which added the fixed outboard wing tanks. As the series continued to evolve, engines were uprated, the tail cropped to better meet the challenges of the low altitude penetration mission, and color schemes changed from silver/white to camouflaged to dark grey. A host of weapons, guided and unguided, nuclear and non-nuclear, powered or gravity-dropped were added to the inventory. The final production variant, the B-52H, rolled off the line in May 1961. Final production numbers:

  • XB-52 - The first B-52 prototype. 1 built
  • YB-52 - The second prototype. 1 built
  • B-52A - The first production model. 3 built
  • NB-52A - 1 aircraft rebuilt to carry the X-15 research aircraft.
  • B-52B - 50
  • NB-52B - 1 aircraft rebuilt to carry the X-15 research aircraft.
  • RB-52B - 27 B-52Bs converted into reconnaissance aircraft.
  • B-52C - 35
  • B-52D - 170
  • B-52E - 100
  • B-52F - 89
  • B-52G - 193
  • B-52H - 102
    • Total produced – 744

The BUFF – First Person Singular

Your Humble Scribe has had several up close/personal encounters with the BUFF. After all, growing up in the shadow of SAC HQ how could one not? Setting aside for the moment the first glimpse of the BUFF in a flyover at the annual Offutt air show (which to YHS, was more sacred than a pilgrimage to Mecca), the first real encounter was with the B-52B at the SAC museum, which used to be located on the outlying regions of Offutt. There, a collection of aircraft lay under the Nebraska sun, generally neglected except for an occasional visit by a long-retired vet or a young lad with a strong imagination. Poking around the aircraft (whilst avoiding the oversight of the security guard who was more interested in staying out of the hot sun), he found the locks on some aircraft easily bypassed opening whole new avenues of investigation. Chief among these were the B-52, with access to its crew tunnel via the main landing gear wheel well offering up both the cockpit and the gunner’s position in the tail. Eventually, one summer he found more robust locks and rivets sealing access, leaving lazy afternoons of daydreaming in cockpits to a thing of the past.

Fast forward a decade (or so) and our subject now finds himself roughly mid-way through what would be a 9 month deployment, most of which was spent drilling holes on Gonzo station (off Iran). On this day he was up for his E-2C Mission Commander check flight. The focus of the flight was support for a pair of B-52H’s inbound from Minot AFB for a minex with the battle group. Lot’s of Xs were to be met that day across the CVBG as the BUFFs brought with them tough ECM gear to challenge the detection and intercept capabilities of the battle group – training that was hard to find on workups, much less on deployment. The other good thing was that unlike other platforms which tended to take on station times as merely advisory, one could count on the BUFFs showing up on time – always. True to form, at the very edge of the detection envelope there was the first hit on radar. Contacted first via HF information passed and the first of the intercept runs begun. The mission would prove to be a challenging one for all involved – the long flight for the BUFFs, refractive layers wreaking havoc with UHF comms and radar tracking for the CICO evaluee, a sudden paucity of F-14s (down to a single F-14) for intercept runs and indications that the Soviets were coming down in the killer Mays (IL-38s) from Aden, which, of course, Intel during the brief had said wouldn’t happen. Right. Five hours and several intercepts/tanker join-ups later for the sole F-14, the evaluee traps back aboard IKE, with a strong recommendation from the STANEVAL for designation as CICO. The BUFFs are back outbound and the F-14? Still airborne and getting one sore tail (quadruple-cycled and these were real 1+45’s).

Oh yes, it also starred in one of YHS’ top 10 favorite movies...

Dropping Stuff

Over the course of its lifetime the BUFF has been responsible for dropping the mundane and the exotic (though by all accounts, a toilet was not included). Besides the usual iron bombs, the BUFF also counted:

  • The largest-yield nuclear weapon in the US inventory – the Mk 41 thermonuclear bomb. The Mk-41 was the only three-stage thermonuclear weapon ever deployed by the U.S. It weighed 4,840 kilograms and was 3.8 meters long. It could be carried by the B-52 or the B-47. While about 500 were built from September 1960 to June 1962, retirement began in November 1963 and the last B41s withdrawn in July 1976. A 25 mt yield for the B41 would give it a yield-to-weight ratio of 5.2 kilotons/kilogram.
  • The Lockheed D-21 (Project Tagboard): An unmanned or "drone" aircraft designed to carry out high-speed, high-altitude strategic reconnaissance missions over hostile territory. It is a product of the Lockheed "Skunk Works" program that developed the A-12, YF-12, and SR-71 "Blackbird" manned aircraft in the 1960's. The D-21 ramjet-powered reconnaissance drone was powered by a Marquardt RJ-43-MA-11 ramjet. Cruising at Mach 3.3 at an altitude of 90,000 feet, the D-21 had a range of over 3400 nautical miles. The D-21 was guided by an inertial navigation system on a pre-programmed flight profile. Originally, the D-21 was designed to be launched from the back of a modified A-12 (redesignated M-12) carrier aircraft. The first flight of the D-21/M-12 combination took place on December 22, 1964, but the first D-21 release from an M-12 did not occur until March 5, 1966. two more launches were successful, but on July 30, 1966, a D-21 collided with the M-12 after release, destroying both aircraft and resulting in the death of one of the M-12's crew members. No further "piggyback" launches were attempted. A new launch system was developed using modified B-52H aircraft as carriers. The new D-21 configuration (designated D-21B) had dorsal mounting hooks for carriage under the B-52's wing, and a solid rocket booster for the initial acceleration required to start the ramjet engine. The first launch from a B-52 took place on November 6, 1967, but the D-21 crashed. Several flights followed in 1968 with mixed success.
GAM-87 Skybolt air-launched ICBM: The Douglas GAM-87A Skybolt was an air-launched ballistic missile (ALBM) developed during the late 1950s. It was intended to provide a "safer" basing for the USAF's ICBM missile force, on its mobile bomber fleet rather than fixed missile silos. A series of test failures eventually led to its cancellation, much to the consternation of the British who had joined the program. The GAM-87 was a ballistic missile powered by a two-stage solid-fuel rocket motor. Each B-52H was to carry four missiles, two under each wing on side-by-side pylons, while the Avro Vulcan carried one each on smaller pylons. By 1961 several test articles were ready for testing from USAF B-52 bombers, with drop-tests starting in January. In England compatibility trials with mockups started on the Vulcan. Powered tests started in April 1962, but the test series was a disaster, with the first five trials ending in failure. The first fully successful flight occurred on December 19th, 1962, but on that same day the whole program was cancelled and the production of the operational GAM-87A stopped. The US simply no longer needed the missile, with improved silo-based missiles and SLBMs making their counterforce largely invulnerable anyway.
  • AGM-84D Harpoon: A BUFF armed to the gills w/Harpoons was a CICOs best friend when running ASUW in the North Atlantic during the Cold War. With lots of loiter time, tough ECM and 8-12 of these hummers slung on wing mounted pylons, one could run some pretty righteous war-at-sea strikes, overloading the bad guys with multiple axis attacks. Between these guys and organic assets (i.e., airwing A-7/A-6’s), we were going Kirov hunting.
  • Test vehicles: “Double Balls 8” (referring to the a/c serial # - 0008) was the famous NB-52B that was a fixture around Edwards AFB and used as the mother ship for the X-15 program. Following in the pattern set by the B-29/X-1 team, the NB-52 carried the X-15 to launch altitude for its test flights. But with the end of the X-15 program, the NB-52 continued to fly with a variety of vehicles for test. The NB-52B launched the three X-15 hypersonic rocket planes and the Northrop HL-10, Northrop M2-F2/F3, Martin Marietta X-24A and Martin Marietta X-24B lifting bodies. It simulated the steep, power off approach to landing used by the Space Shuttles. It assisted in the collection of data about wake turbulence from large aircraft. It served as an air-to-air gunnery target. It launched 3/8-scale F-15 Remotely Piloted Research Vehicles (RPRV), a Ryan Firebee II drone, Ryan Firebee based Drones for Aeroelastic Structures Testing (DAST), and the Highly Maneuverable Aircraft Technology (HiMAT) RPRVs. It dropped the 48,000-pound Space Shuttle Reusable Booster Drop Test Vehicle (SRB/DTV) and it released a simulated F-111 crew module from its bomb bay to evaluate new parachute recovery systems. It was the first airplane to launch a satellite into orbit on the Orbital Sciences Pegasus booster. It tested the drag chute used to decelerate space shuttle orbiters. It tested pollution reducing fuel additives with a pair of jet engines mounted under its bomb bay. It launched the X-38 Space Station Crew Return Vehicles and the X-43A Hyper-X Supersonic Combustion Ramjet. A unique aspect for the NB-52 was the tally board for each mission flown. Besides the usual suspects (X-15, Pegasus, etc.) there are a few gems of wry humor to be found sprinkled around.

BUFF Trivia:

  • B-52 flies unlike other aircraft. Shortly after take-off, as it gains speed, the nose dips and it climbs in an initial nose-low attitude, a consequence of high camber of its wing in the full flaps configuration. This looks strange to most people, who are used to seeing aircraft take off nose-high.
  • An aircraft of this massive size, power and weight necessitates hydraulically boosted control surfaces. However, B-29 Superfortress pilots, who were used to using brute force from the human body to actuate the control surfaces, would be transferred to the B-52, which had hydraulic controls. Therefore, strong springs are used to help imitate the control feel of the older aircraft. As a result the B-52 is a physically demanding aircraft to fly.
  • The B-52's skin looks wrinkled when the aircraft is on the ground. In flight, the wrinkles disappear as the wing loading causes the wings and airframe to flex to in-flight configurations.

  • The ejection seats for the lower-deck crewmembers, the Navigator and Radar Navigator, eject downwards. Because of this, these crewmembers cannot eject at an altitude of 200 feet or less. A Navigator and a Radar Navigator from Fairchild AFB both survived a downward ejection at approximately 200 feet above ground level in a training accident near Kayenta, Arizona on the evening of October 20, 1984. The upper deck crewmembers (Pilot, Copilot, and Electronic Warfare Officer) have seats which eject them upwards. Their seats work at any altitude, as long as the airspeed is at least 90 knots. This is necessary to inflate their parachutes, since their ejection seats are blast propelled and not rocket propelled, and are not 0-0 certified as are more modern ACES-II ejection seats.

  • There is a story told by many B-52 pilots that sums up the aircraft: "The B-52, with its familiar wrinkled fuselage sides, has enough metal to make 10,000 garbage cans. The wiring in the Stratofortress is equivalent to five miles of baling wire. Its engines are as powerful as eight locomotives. And that's the way it flies, like eight locomotives, pulling ten thousand garbage cans with five miles of baling wire!"

  • The B-52 on static display outside Offutt Air Force Base, Nebraska, has a patch on the cockpit. The damage was caused by impact with an American Bald Eagle during landing.
  • As part of the 1991 Strategic Arms Reduction Treaty between the United States and Russia, 365 B-52Gs were flown to the Aerospace Maintenance and Regeneration Center at Davis-Monthan Air Force Base in Arizona. The bombers were stripped of all usable parts, then chopped into five pieces by a 13,000-pound steel blade dropped from a crane. The guillotine sliced four times on each plane, severing the wings and leaving the fuselage in three pieces. The ruined B-52s remained in place for three months so that Russian satellites could confirm that the bombers had been destroyed, after which they were sold for scrap.

  • During the early morning of January 17, 1991 the first day of operation Desert Storm a B-52G (aircraft 0248) was fired upon by an F-4G Wild Weasel. The B-52's tail gunner locked his tail gun radar on the Wild Weasel mistaking it for an Iraqi MIG. The Wild Weasel immediately detected the B-52 tail gun radar and misidentified the radar signature as an Iraqi Anti-Aircraft Artillery (AAA) site. The F-4G Wild Weasel crew fired a single AGM-88 HARM anti-radiation missile and watched in horror as it headed not towards the non-existent Iraqi AAA site, but to one of the B-52 bombers it was tasked with protecting. Luckily the missile failed to hit the plane, but instead detonated directly behind the bomber. The shrapnel and missile debris damaged the tail section of the B-52G. It ripped off everything aft of the vertical stabilizer. This included much of the tail gun system, the aft Electronic Warfare suite, and the drag chute. The B-52G was able to return safely to the island of Diego Garcia. It was later fully repaired at Anderson Air Force Base on Guam where it was renamed "IN HARM's WAY". The tail gunner position was subsequently eliminated from the entire B-52 fleet.