F-III/FB-III
The FB-111 was the strategic/theater bomber version of the US F-l 11 multipurpose aircraft. Both are described here. The FB-111 design differs from the tactical strike aircraft variants by having different engines, a SVa-ft (1.07-m) extension on each wingtip, strengthened landing gear and fuselage, greater fuel capacity, and improved avionics.
In the basic F-l 11 design, the pivot points for the variable-sweep, shoulder-mounted wings are located relatively close to the fuselage inside fixed wing “gloves”; the gloves extend forward to the rear of the cockpit and give the plane a “hooded cobra” look. Although the close-set pivots complicated design and required a titanium wing carry-through structure, they also result in a low minimum sweep angle of 16° and a high maximum sweep angle of 72V2°; such a wide range results in an aircraft with relatively low takeoff, landing, and stall speeds as well as supersonic, low-altitude penetration flight.
High lift surfaces line the full span of the leading and trailing edges of the wing; the trailing-edge flaps are double-slotted. Roll control is achieved through spoilers and large, all-moving swept tail-planes that move differentially for roll, collectively for pitch. The broad-chord, swept fin has a full-height rudder.
The two TF-30-P-7 twin-spool turbofan engines are buried in the aft fuselage and fed by variable-area intakes that are fitted with boundary-layer splitter plates and located on the fuselage flanks under the leading edge of the fixed wing gloves. The engines are fitted with variable-area nozzles with blow-in door ejector. Fuel tanks occupy much of the fuselage ahead and behind the wing carry-through structure as well as most of each wing. All F/FB-111s have in-flight refueling capability.
The fuselage is broad enough to accommodate a side-by-side cockpit for the pilot and navigator. The aircraft’s maximum design load factor at design weight is 3 g.
The cockpit is protected by individual canopies over each seat; these are hinged on a common centerline rail and, when open at the same time, have a gull-wing appearance. The cockpit and glazing are combined in an escape pod that is ejected by a single rocket; the crew remains with the pod while it parachutes to earth.
The F/FB-111′s high wing-loading and low aspect ratio at full aft sweep makes the aircraft relatively insensitive to low-level turbulence, which extends its low-altitude, terrain-following flight endurance. In low-level flight, the primary avionics unit is the Texas Instruments AN/APQ-117 Terrain-Following Radar
F-III
U.S. GOVERNMENT DEPARTMENT OF DEFENSE
(TFR) fitted in the nose radome. Other avionics include the General Electric AN/APQ-117 attack radar (upgraded to the AN/APQ-169), General Dynamics
AN/AYK-6 digital computer, AN/AYN-3
Horizontal Situation Display, AN/ASG-25 optical display sight, AN/AJN-16 iner-tial bomb navigation system, AN/APN-167 radar altimeter, and AN/APN-185 Doppler radar.
The comprehensive Electronic Support Measures/Electronic Counter-measures (ESM/ECM) suite includes a Cincinnati Electric AN/AAR-3 4 Infrared (IR) warning receiver, Loral AN/ALR-41 homing receiver, Dalmo Victor AN/ APS-109B Radar Homing and Warning
System (RHAWS), Sanders AN/ALQ-94
or AN/ALQ-137 internal noise/deception jammer, and an AN/ALE-28 coun-termeasures dispenser.
The internal weapons bay is located between the nose and main gear bays and has a volume of 126 ft3 (3.57 m3). The bay carries either two nuclear bombs or two AGM-69 nuclear Short-Range Attack Missiles (SRAM). Of the six external weapons pylons, the center and inboard pylons under each wing swivel with the wing sweep. The outermost pylon on each wing is fixed so that it creates the least drag at a 26° sweep angle; these pylons are used for fuel tanks and are jettisoned with the tanks when the latter are empty. The other four pylons carry SRAMs, nuclear bombs, conventional 750-lb (340-kg) bombs, cluster bombs, or 600-US gal (2,271-liter) drop tanks.
DEVELOPMENT •
The FB-lll’s initial operational capability was in October 1969, and its first flight was in July 1967. While in production from 1968 to 1971, 76 were built. The last was retired on July 10,1991. 22 FB-llls, designated FB-lllGs, were converted to trainers beginning in June 1990 and would be retired by early 1994 at the latest.
An unofficial US Air Force nickname for the F/FB-111 is the Aardvark, referring to the long nose. The FB-111 saw service only with the USAF and is no longer in operation; the F-lll is in service with Australia.
VARIANTS •
FB-111A, FB-111G, FB-111H (upgraded engines, stretched fuselage), F-lll G.
COMBAT EXPERIENCE •
First combat use of the US Air Force F-lll aircraft came in 1972-1973 with limited results and relatively heavy losses during raids into North Vietnam.
Twelve England-based F-lllFs aircraft attacked Libyan targets at night on April 15,1986. (Five more developed problems that forced them to turn back.) One was lost with its two-man crew. Each F-l 11 required three in-flight refuellings enroute to the target and two more on the return flight.
On January 17, 1991, the 38 F-lllFs deployed in the region attacked Iraqi targets as part of the air assault that began Operation Desert Storm. Together with the F-l 17 Stealth “Fighter” and the F-15E Eagle, the F-lllFs were responsible for many of the precision-bombing strikes using laser-guided bombs that dislocated the Iraqi air-defense system. F-lllFs also attacked Scud fixed and mobile ballistic missile sites, as well as delivering LGBs against 1,500 armored vehicles (known as “tank plinking”). No F-l 11s were lost in the seven-week campaign.
SPECIFICATIONS (FB-111) •
MANUFACTURER General Dynamics CREW 2 (pilot, navigator) ENGINES 2 Pratt & Whitney TF30-P-7 turbofan
maxpower with afterburner: 20,350 Ib (9,231 kg) st (static thrust) each intermediate without afterburner: 12,350 Ib
(5,602 kg) st each
max fuel capacity: 5,623
US gal (19,088 liters)
| WEIGHTS | radar AN/APQ-134 or -171 |
| empty 47,481 Ib (21,537 kg) | TFR |
| combat 70,380 Ib (31,924 kg) | AN/APQ414or-169 |
| design 110,646 Ib (50,188 kg) | attack |
| max takeoff 119,243 Ib (54,088 kg) | |
| DIMENSIONS | SPECIFICATIONS (F-111) • |
| wingspan 70 ft (21.34 m) extended, | MANUFACTURER General Dynamics |
| 33 ft 11 in (10.34m) | CREW 2 (pilot, navigator) |
| swept | ENGINES |
| length 75 ft 6Vs in (23.03 m) | F-111A: 2 Pratt & Whitney TF30-P-3 |
| height 17 ft 1 in (5.22 m) | turbofan |
| wing area 550 ft2 (51.11 m2) | F-111F: 2 Pratt & Whitney TF30-P-100 |
| PERFORMANCE | turbofan |
| max speed at high altitude | max power with afterburner |
| l,262kts(l,453mph; | F-111A18,500 Ib (8,391 |
| 2,338 km/h) or Mach | kg) st each |
| 2.2 | F-111F 25,100 Ib (11,385 |
| basic speed at 35,000ft (10,668 m) | kg) st each |
| 1,188 kts (1,368 mph; | maxfuel capacity |
| 2,201 km/h) or Mach | 5,043 US gal (19,088 liters) |
| 2.05 | WEIGHTS |
| max combat speed at sea level | empty F-111A: 46,172 Ib (20,943 |
| 728 kts (838 mph; 1,349 | kg) |
| km/h) or Mach 1.1 | F-111F: 47,481 Ib (21,537 |
| max dash speed, high altitude | kg) |
| 1,147 kts (1,321 mph; | combat weight |
| 2,125 km/h) or | F-111A: 64,728 Ib (29,360 kg) |
| Mach 2 | F-111F: 63,048 Ib (28,598 kg) |
| max dash speed, low-level | typical takeoff |
| 562 kts (647 mph; 1,041 | F-111A: 82,819 Ib (37,566 kg) |
| km/h) or Mach 0.85 | F-111F: 85,589 Ib (38,823 kg) |
| range cruise | max takeoff F-111A: 98,850 Ib (44,838 |
| 444 kts (511 mph; 823 | kg) |
| km/h) | F-111F: 100,000 Ib |
| max rate of climb, with external weapons | (45,360 kg) |
| stores | DIMENSIONS |
| 22,870 ft/min (6,971 | wingspan 63 ft (19.2 m) extended, |
| m/min) | 31 ft 11 in (9.74m) |
| ceiling at combat weight | swept |
| 50,263 ft (15,320m) | length 73 ft 6 in (22.4 m) |
| armament internal weapons bay with | height 17 ft 1 in ( 5.22 m) |
| 2B43/B61/B83 | wing area 525 ft2 (48.77 m2) |
| nuclear bombs | PERFORMANCE |
| and 6 wing pylons for up | max speed at high altitude |
| to 31,500 Ib (14,288 | F-111A: 1,262 kts (1,453 |
| kg) weapons load | mph; 2,338 km/h) or |
| including: | Mach 2.2 |
| 4SRAMs | F-111F: 1,436 kts (1,653 |
| or24750-lb (340-kg) | mph; 2,660 km/h) or |
| Ml 17 bombs | Mach 2.5 |
basic speed at 35,000ft (10,668 m) 1,196 kts (1,377 mph; 2,216 km/h) or Mach 2.1
max combat speed at sea level
794 kts (914 mph; 1,471 km/h) or Mach 1.2
range cruise
444 kts (511 mph; 823 km/h)
max rate of climb with external weapons stores
F-111A 26,600 ft/min (8,108 m/min)
F-111F: 43,050 ft/min
(13,122 m/min)
ceiling at combat weight
F-l 11A: 55,300 ft (16,855 m)
F-111F: 57,100 ft (17,404
m)
radius F-l 11A, hi-lo-lo-lo-hi at combat weight with 12 750-lb (340-kg) bombs: 681 nm (784 mi; 1,262
km)
F-l 1 IF, hi-lo-hi at combat weight with 24
750-lb (340-kg) bombs:
440 nm (507 mi; 815 km)
range with 4 600-USgal (2,271-liter) drop tanks
F-lllA:3,156nm (3,634
mi; 5,848 km)
F-l 1 IF: 2,934 nm (3,379
mi; 5,437 km)
armament internal weapons bay for 1 M61A1 20-mm gun
(2,050 rounds)
and 1 B43 nuclear bomb or 2 B43/61/83 nuclear
bombs and 4 wing pylons for
31,500-lb (14,288-kg)
weapons load or4 AIM-9 Sidewinder
AAM
or 4 600-US gal (2,271-liter) drop tanks
Lancer(B-l)
The B-l is the long-range strategic bomber designed originally for low-altitude penetration missions against mobile ICBMs or standoff Air-Launched Cruise Missile (ALCM) attacks. 100 were procured in the early 1980s as a “bridge” in capability between the aging B-52 Stratofortress and the planned B-2 Advanced Technology Bomber (ATB or “Stealth”).
The B-1B features variable-geometry wings mounted at midfuselage. The wing pivot is located relatively close to the fuselage, which yields a large change in wing aspect ratio from its minimum sweep angle of 15° to the maximum sweep angle of 67!/2°. As with several other “swing-wing” aircraft designs, the pivots and wing carry-through structure are titanium. The outer panels are of more conventional aluminum-alloy construction.
In addition to the low-sweep angle, takeoff and landing performance is aided by leading- and trailing-edge lift devices. Each leading edge has full-span slats in seven sections that droop 20° for takeoff. Each trailing edge is fitted with six single-slotted flap sections with a maximum down flap setting of 40°. Roll control is provided by four sections of spoilers on each wing; there are no ailerons.
The vertical tail is a relatively upright surface made of titanium and aluminum alloy. The three-section rudder is inset into the trailing edge with the lowest section set below the tailplane. Large, swept tailplanes are mounted on a common spindle that passes through the fin at a reinforced station approximately one-third up the fin. The tailplanes can be used differentially to aid roll control as well as collectively for pitch control.
Four independent 4,000-psi (276-bar) hydraulic systems power the flight controls, flaps, landing-gear actuation, landing-gear doors, and weapons-bay doors. A quadruplex Automatic Flight
Control System (AFCS) is fitted. Ride control at low altitudes is provided by the Structural Mode Control Subsystem (SMCS) that uses accelerometers to dampen the rough ride at low altitude. Two small, swept vanes are fitted at 30° anhedral in the lower fuselage just ahead of the cockpit; these work in conjunction with the lowest rudder section under command of the SMCS.
The B-1B initially had little inherent stall warning, and its terrain-following performance had deteriorated due to the substantially higher gross weights compared to the B-1A. A Stall Inhibitor System (SIS-1) was fitted to the first 18 aircraft to force the pilot to “fail-safe” by limiting his control system power near the B-lB’s Angle of Attack (AoA) limits.
A later SIS-2 is a backup to the triple-redundant Stability Enhancement Function (SEF), which is designed to expand the AoA limits and permit Mach 0.95 speeds at max gross weight from sea level to about 6,000 ft (1,829 m) while retaining an adequate margin of controllability. In addition to reducing the necessary stall warning margin from 20% to 5% above aerodynamic stall, the SEF system has permitted successful automatic terrain-following flights at 200 ft (61 m) in a “hard-ride,” hands-off mode. All
B-lBs were retrofitted with the SIS-2/SEF system, with fully equipped B-lBs entering squadron service between January and April 1990.
Four General Electric turbofans are housed in pairs in nacelles under the wings. They are fed through fixed-geometry intakes that limit maximum speed to approximately Mach 1.25. Problems with the engine’s first-stage compressor fan led to the Air Force’s cessation of all B-l routine training flights in December 1990 until the source of the failures could be found.
Internal fuel tankage is located in the fuselage midbody and in the outer wings.
The in-flight refueling receptacle is fitted ahead of the cockpit.
The fuselage has a blended wing-body union similar to that of the F-16 Fighting Falcon. The B-lB’s Radar Cross Section (RCS) that gives the plane its “stealthi-ness” is approximately ¥7 that of the FB-111A, Via of the B-1A, and VIM of the B-52. The small RCS is achieved through shaping and Radar-Absorbent Materials (RAM) used at many points on the air-frame.
Although much of the structure is aluminum alloy, titanium is used where high heat is generated (firewalls, engine bays) or high stress is expected (tail, rear fuselage skinning). The main landing gear was strengthened to accept the B-lB’s higher gross weights; the two four-wheel bogies retract into the fuselage between the engine nacelles. The nose gear retracts forward.
The pressurized flight deck provides for two pilots and two weapons systems officers, each seated in his own Weber ACES II ejection seat. The pilots use control sticks rather than wheels and have the engine throttles on consoles to the left of each seat, which is said to enhance the aircraft’s fighterlike feel. Instrument displays include vertical tape displays and Sperry Multifunction Displays (MFD).
Avionics are grouped under two main systems: the Boeing Offensive Avionics System (OAS) and Eaton-AIL AN/ALQ-161 Electronic Countermeasures (ECM) suite; together the two suites account for over 197 Line Replaceable Units (LRU) weighing more than 10,000 Ib (4,536 kg). The main systems computers are linked through a MIL-STD-1553 databus.
The Westinghouse AN/APQ-164 dual-channel, multimode Offensive Radar System (ORS) is based on the F-16′s APG-66 and is located in the nose. Additional OAS avionics include dual Honeywell AN/APN-224 radar altimeter systems, the Teledyne Ryan AN/APN-218 Dop-pler velocity sensor, and three Sperry
MFDs, two for the offensive-weapons officer and one for the defensive-weapons officer. The Air Force plans to fit a Forward-Looking Infrared (FLIR) sensor.
The AN/ALQ-161 detects, classifies, and analyzes enemy emitters and develops passive and active responses to them. Three sets of phased-array antennas are fitted in the wing leading edges and the tail for high-frequency coverage while other antennas are distributed at several points of the fuselage. The ALQ-161 has suffered significant problems and has frequency gaps in its passive coverage. In January 1989, the Loral AN/ALR-56M radar-warning system was selected to fill in those gaps.
Internal weapons are carried in weapons bays ahead and behind the wing carry-through structure. The 31-ft 3-in (9.53-m), two-section forward bay has a movable bulkhead that allows stowage of eight extended-range AGM-86B Air-Launched Cruise Missiles (ALCM) on a Common Strategic Rotary Launcher (CSRL). The bays can also hold nuclear gravity bombs.
When converted to the conventional role, a special bomb-handling module is inserted into each bay. As a result, up to 84 Mk 82 500-pound conventional bombs can be carried. The Air Force would also like to carry CBU-87, CBU-89, and CBU-97 cluster munitions dispensers as well as Mk 56, Mk 62, and Mk 65 un-guided weapons. Eight external-stores stations under the fuselage can hold additional weapons such as the Paveway Laser-Guided Bomb (LGB) series, the
AGM-137 Tri-Service Standoff Missile
(TSSAM), and possibly the AIM-120 AM-RAAM air-to-air missile. Up to 24 GBU-10 2,000-lb (907-kg) LGBs can be carried at once.
DEVELOPMENT •
The B-lB’s initial operational capability was on October 1, 1986. The aircraft’s first flight was a B-1A on December 23,1974; the B-1B first flew
on March 23,1983. Four B-1A prototypes were built in the mid-1970s and used for test and evaluation.
The Air Force had originally proposed a force of 244 B-ls to replace the entire B-52 force. Production was approved on December 2, 1976, but the Carter administration entered office a month later, and in June 1977, die entire program was canceled in favor of the development of theAir-Launched Cruise Missile (ALCM) and modernization of the B-52 force as an alternative.
The manned bomber became an issue in the 1980 presidential campaign. In August 1980, to help justify the decision to cancel the B-l, then Secretary of Defense Harold Brown announced that the US was in fact developing a new bomber in secret, the “Stealth” aircraft (later called the B-2 Advanced Technology Bomber or ATB). The Reagan administration, which took office inJanuary 1981, gave immediate support to the B-l program (reportedly based on successful test flights that demonstrated the upgraded bomber’s stealthier qualities), and gained congressional funding.
100 B-lBs were acquired by the US Air Force, funded as follows:
| FISCAL YEAH | AIRCRAFT |
| 1982 | 1 |
| 1983 | 7 |
| 1984 | 10 |
| 1985 | 34 |
| 1986 | 48 |
A crash in September 1987 and two crashes in November 1988 reduced the number in service to 97. The last aircraft was delivered on April 30, 1988.
The name Lancer was officially adopted in 1990 after permission had been granted from Fairchild Republic to use the nickname, which in 1941 was assigned to the P-43 fighter, an underpowered predecessor of the Republic P-47 Thunderbolt. Air Force personnel reportedly never refer to the B-l as the
Lancer, choosing instead to call it the
Bone (“B-One”).
As part of the overall reduction in active US nuclear weapons, President George Bush announced that all US strategic bombers were taken off 24-hour strip alert and their nuclear weapons put in storage.
A B-1B unofficially set several flight records in early July 1987. While carrying 33 tons of water as ballast, the aircraft averaged 676.48 mph on a 620-mile (1,000-km) course, and 669.52 mph
on a 1,240-mile (2,000-km) circuit. The previous records for that weight/ speed/distance were set, respectively, in 1959 by a Soviet bomber and in 1962 by a US Air Force C-135 transport. The B-l set 12 time-to-climb records in three weight classes on February 29, 1992
VARIANTS •
B-1A, B-1B.
COMBAT EXPERIENCE •
During the deployment of US weapons for Operation Desert Storm in February 1991, the potential role of the B-l was debated, but the aircraft was held out of the conflict. The Air Force gave two official reasons for the B-l not being used: because there were not enough available to significantly contribute to the effort without degrading strategic deterrence and because the B-l simply wasn’t operationally prepared to deploy with conventional arms.
SPECIFICATIONS •
MANUFACTURER Rockwell International CREW 4 (2 pilots, 2 systems operators) ENGINES 4 General Electric F101-GE-F102 turbofan
max power 30,000 Ib (13,620 kg) static thrust each
fuel capacity
196,600 Ib (89,176 kg)
with bay tank
214,000 Ib (97,069 kg)
WEIGHTS
empty 192,000 Ib (87,090 kg)
max internal weapons load
75,000 Ib (34,019 kg)
max external weapons load
59,000 Ib (26,762 kg)
max takeoff 477,000 Ib (216,365 kg) DIMENSIONS
wingspan extended: 136 ft 8Va in (41.67 m) (15° sweep) 67.5° sweep: 78 ft 2M> in (23.84 m) length 147 ft (44.81 m)
height 34 ft (10.36m)
wing area 1,950 ft2 (181.2 m2)
PERFORMANCE
max speed at altitude: 717 kts (826 mph; 1,329 km/h) or
Mach 1.25
at 500 ft (152m): 660 kts
(760 mph; 1,223 km/h) or Mach 0.99
cruise speed
at low altitude: 550 kts (633 mph; 1,019
km/h) or Mach 0.83
ceiling 60,000 ft (18,300 m) combat radius
l,100nm (1,267 mi; 2,037 km) range max at high altitude:
5,600 nm (6,449 mi;
10,377 km)
low altitude with 8 SRAM
and 8 B-61 bombs:
1,500 nm (1,727 mi; 2,780 km)
armament 2 internal weapons bays
for up to 42,000 Ib of
ordnance, such as: 84 Mk 82 500-lb bombs or24Mk842,000-lb
bombs or 12 B28 free-fall nuclear
bombs or 24 B61/B83 free-fall
nuclear bombs or 24 Short-Range Attack
Missiles (SRAM) or 8 Air-Launched Cruise
Missiles (ALCM) and 8
hardpoints under
fuselage for 14 ALCM
or SRAM
or8B28
or!4B43/B61/B83 nuclear or Mk 84 conventional bombs
or 44 Mk 82 radar AN/APQ464 forward-
looking
Stealth (B-2)
The Advanced Technology Bomber (ATB) is popularly called the Stealth bomber but its official name is “Spirit.” Although not operational, this controversial batlike aircraft has flown test missions. The combination of its performance problems, the end of the cold war with the collapse of the Soviet Union, and the high cost of the plane may preclude the B-2 from joining the active US Air Force.
The B-2 was designed to complement the B-1B. It is designed to present the lowest possible visual, radar, acoustic, and infrared signatures. Its original mission was to attack mobile ICBMs and hardened command-and-control installations. After the loss of a structured nuclear threat, the aircraft’s mission was redefined to emphasize long-range conventional strike missions.
The B-2 achieves “invisibility” to radar and infrared sensors for as long as possible by reducing the aircraft’s Radar Cross Section (RCS) and decreasing engine exhaust gas temperatures; it also is claimed to be 50% more aerodynamically efficient than the B-l.
The B-2′s general design resembles earlier Northrop flying wings (the YB-35 and YB-49 of the 1940s), a configuration that has the smallest head-on and side-view RCS. A further reduction in RCS is attained by using surface skins made of a composite, ferrite-based carbon-fiber honeycomb Radar Absorbent Structure (RAS) over titanium main structural members.
The wing carry-through section was modified in 1984 from single front and rear spars to narrow torque boxes to enable the aircraft to better withstand low-level flight and to reduce the wing’s weight. The wing is quite rigid, showing only Viath the deflection that the B-52 shows at high load.
The wing’s leading edges are swept at approximately 40° to tips that are raked back toward the centerline to decrease the flying wing’s tendency to yaw while rolling. The wing’s sawtooth trailing edge is unique, designed to cope with a flying wing’s natural instability even as it helps to reduce RCS and exhaust heat signature.
At approximately midspan (moving toward the fuselage), the trailing edges turn and head aft to a pointjust outboard of the engine installations on each side. The two control surfaces are elevens that can also be used as flaps. At this point, the trailing edges again turn almost 90°, heading forward to a point directly aft of the center of the unusual engine exhausts. Finally, the two halves ofthe flying wing’s trailing edge turn aft and meet in a movable fuselage “beavertail,” which operates with the elevens for gust alleviation. The hydraulic actuators are the fast-action type and are supported by a 4,000-psi (281.2-kg/cm2) system.
When seen from ahead, the fuselage is thickest through the center, with the cross section tapering out to the outer panels. Over the center section are two low engine intakes, one on each side of a shallow, rounded cockpit section that has large window panels. The windshield is designed to be a load-bearing structure and has an integral metal mesh designed to prevent strong returns from the glazing or emission leakage from flight deck instruments or systems.
The two four-wheel, main-landing-gear bogies retract inward while the wheels are stowed close to the centerline. The two-
wheel nose gear retracts to the rear. The aircraft is able to use any runway that will support a Boeing 727 jet transport.
Each engine intake feeds two of the four GE nonafterburning turbofan engines that are in the wing. Each engine intake has two rear-hinged auxiliary inlet doors that face forward and are angled off the centerline. These doors are open at low speeds to provide sufficient airflow to the engines.
In October 1990, Northrop was contracted to convert the B-2′s fuel system from JP-4 fuel, which requires pressuriza-tion, to JP-8, which has a higher flash point.
The two-man cockpit has control sticks linked to a computer-controlled, quadruple-redundant Stability Augmentation System (SAS) produced by General Electric. Honeywell is developing the Radar
Altimeter Set (RAS) and GEC Avionics
(formerly Kearfott) is responsible for the advanced Inertial Navigation System (INS). The aircraft has two flat-plate antennas for the Hughes AN/APQ-181 multimode phased-array radar. Multifunction Displays (MFD) provide instrumentation, navigation, and attack information.
Nuclear weapons such as gravity bombs and Short-Range Attack Missiles (SRAM) are carried in side-by-side internal weapons bays. Up to 16 B83 gravity bombs, AGM-69A SRAM or AGM-131
SRAM II cruise missiles, or 20 smaller nuclear weapons could be stowed; alternative loads include up to 80 conventional 500-lb (227-kg) bombs or sea mines.
DEVELOPMENT •
The B-2 is under development. First flight had originally been planned for late 1987, but a $1-billion design modification to permit low-level flight delayed the program. After high- and low-speed taxi tests, the first flight took place on July 17, 1989, at Edwards AFB, California. First flight of the second aircraft came on October 19,1990; this aircraft (AV-2) is the only one of the six test aircraft not to be refitted as an operational bomber.
The planned total number of aircraft has been reduced first from 132 to 75 aircraft and then to 20. The initial operational capability is currently planned for the mid-1990s. When the 20 B-2 bombers are properly equipped near the turn of the century, they could drop 160 tons of bombs a day in a war area, compared to the 146 tons/day dropped by 20 B-52 bombers in Operations Desert Shield/ Desert Storm.
SPECIFICATIONS •
MANUFACTURER
Northrop Grumman Vought (former LTV) (subcontractor) Boeing Advanced Systems (subcontractor)
CREW 2 (pilot, weapons systems officer)
ENGINES 4 General Electric F118-GE-
100 turbofan
maxpower 19,000 Ib (8,618 kg) static thrust each
WEIGHTS
empty weight approx 158,000 Ib
(71,668kg)
max takeoff 240,000-376,000 Ib
(108,862-170,551kg)
maxpayload 50,000 Ib (22,680 kg) internal
DIMENSIONS
wingspan 172 ft (52.42 m) length 69ft (21.03m)
height 17 ft (5.18 m)
wing area more than 5,000 ft2 (464.5 m2)
PERFORMANCE
speed Mach 0.85
operational ceiling
approx 50,000 ft (15,240
m) with weapons load
range (w/weapons)
high altitude: 6,600 nm (7,600 mi; 12,230 km)
hi-lo-hi: 4,500 nm (5,182 mi; 8,339 km)
hi-lo-hi (optimized): 5,400 nm (6,218 mi; 10,006 km) armament 2 internal weapons bays for up to:
16 B83 gravity bombs, AGM-69A SRAM or AGM-131 SRAM II cruise missiles
or 20 smaller nuclear weapons (e.g., B61 gravity bombs)
wupto80500-lb (227kg) bombs or sea mines
radar Hughes APQ-181
multimode
Stratofortress (B-52)
The B-52 strategic bomber celebrated its 40th anniversary in 1992 and is still operational. Its mission has been altered several times since its inception, to adjust to US military operational requirements. B-52s were used in the conventional bombing role in the Vietnam War and some are now dedicated to conventional strike missions.
The B-52 is a multiengine, long-range aircraft capable of both conventional free-fall bomb delivery and air-to-ground missile launch missions. The B-52 carried the largest nuclear payload of any US strategic platform.
The B-52 has long shoulder wings swept at 36° and has a relatively high aspect ratio of 8.5; the wings flex considerably during flight. Each wing has two engine pods spaced equidistantly along its leading edge; each pod carries two engines (all have turbojets but the B-52H, which has turbofans). Retractable outrigger wheels and fuel tank pods are outboard of the engines.
Contemporary B-52s have a 40-ft (12.20-m) tall fin and full-height rudder with squared-off tops; earlier B-52s had a taller, pointed fin. The relatively large, low-aspect-ratio horizontal stabilizers are mounted midfuselage, directly below the tailfin.
In addition to the extensive internal fuel tankage, two 700-US gal (2,650-liter)
drop tanks are usually carried on dedicated pylons outboard of the outer pair of engines.
The fuselage is long, slab-sided, and capacious. The flight deck is well forward, behind a stepped windshield and blunt nose. The two main gear legs are arranged side by side, ahead and behind the weapons bay. The wheels can be “crabbed” into a crosswind, which is a compensation for the aircraft’s inability to drop a wing during a crosswind landing due to its great span. Operational aircraft have undergone extensive offensive avionics and electronic warfare updates as well as improvements to basic systems. In 1969, the G and H models were fitted with a Stability Augmentation System (SAS) to improve low-altitude ride and extend airframe life.
264 B-52G and B-52H aircraft were refitted with the digital, solid-state Offensive Avionics System (OAS) from 1980 to 1986. Two IBM navigational/attack computers coordinate the IBM/ Raytheon AN/ASQ-38 analog bombing and navigational equipment, Teledyne
Ryan AN/APN-218 Common Strategic
Doppler navigation system, Honeywell AN/ASN-131 precision inertial navigation system and AN/APN-224 radar altimeter, and Lear-Siegler Model 6000 series attitude/heading reference system.
As part of the OAS program, the strategic radar has been reworked by Nor-den, incorporating solid-state, digital components to gready improve reliability and to enhance the radar’s ground-mapping and terrain-avoidance capability. The B-52G and B-52H are also fitted with a chin-mounted Electro-Optical Viewing System (EVS), which consists of a Westinghouse AN/AVQ-22 Low-Light-Level TV (LLLTV) and a Hughes AN/AAQA Forward-Looking
B-52
U.S. GOVERNMENT DEPARTMENT OF DEFENSE
Infrared (FLIR) system. B-52Gs were being fitted with a Global Positioning System (GPS) to improve accuracy in long-range strike missions.
Defensive avionics currently include the Northrop AN/ALQ-155 EW power management system, Motorola AN/ ALQ-122 Smart Noise Operation Equipment (SNOE) false target generator, Dalmo Victor ALR-46 digital radar-warning receiver, Westinghouse AN/ ALQ-153 tail-warning system, and ITT AN/ALQ-117 tail-mounted deception jammer for use against radar-guided missiles. B-52Hs are fitted with ALQ-172(V)2 with phased-array antennas.
The weapons payload can be carried in internal weapons bays and on wing pylons located between the inboard pair of engines and the fuselage. 98 B-52Gs carry 12 Air-Launched Cruise Missiles (ALCM) on pylons. 69 non-ALCM B-52Gs are being fitted with the Integrated Conventional Stores Management System (ICSMS), a software upgrade that permits weapons computers to target and launch both nuclear and conventional weapons.
The B-52H has been fitted with the Common Strategic Rotary Launcher (CSRL) in the weapons bay that will carry free-fall nuclear weapons, Short-Range Attack Missiles (SRAM), and ALCMs.
Operational models have an in-flight refueling capability. A remote-control tail turret is fitted, controlled by the AN/ ASG-15 radar gunsight, and is the only gun armament the B-52 has ever carried.
DEVELOPMENT •
Initial operational capability was in June 1955, and the first flight (the YB-52) was on April 15, 1952.
744 aircraft were produced through October 1962. On September 28, 1991, as part of an overall reduction in active US nuclear weapons announced by President Bush, all US strategic bombers were removed from 24-hour strip alert and their nuclear weapons were put in storage. Airframe aging is a problem with some B-52s, since some airframes have been in service for over 30 years. Modernization programs have helped keep the B-52 in operation well into the 1990s. The US Air Force has been the only operator of the B-52.
VARIANTS •
XB-52 (prototype), YB-52, B-52A, NB-52A (NASA), B-52B, B-52C/D (production versions, first flight in 1956),
B-52E, B-52F, B-52G, B-52H.
COMBAT EXPERIENCE •
B-52 aircraft were used for conventional high-altitude bombing operations in the Vietnam War.
The first aircraft to take off on missions supporting Operation Desert Storm’s air assaults on January 17, 1991, were seven B-52s from Barksdale AFB, Louisiana, that departed at 6:35 A.M. GST (1135 Greenwich), almost 12 hours before the first bombs fell. These aircraft carried AGM-86C ALCMs that had been secretly modified to carry conventional warheads and a guidance system based on the GPS.
Approximately I1/? hours after the attacks began, 35 ACLMs were launched against eight “high-priority” targets. What the Air Force later called the longest combat mission in aviation history took 35 hours, covered 14,000 nm (16,121 mi; 25,928 km), and required four refuelings and an augmented crew to complete. No other ALCMs were used during Desert Storm, and damage assessment was difficult to separate from other bomb damage. The mission was termed “successful.”
Despite the bombers’ age, few missions had to be aborted, and the mission-capable rate was over 81%, a 2% increase over peacetime operations.
Over 72,000 weapons were dropped, totaling more than 25,700 tons. This total was 29% of all US bomb tonnage delivered. A total of 60-70 B-52Gs were used against Iraq.
SPECIFICATIONS •
MANUFACTURER Boeing Military Airplane
CREW 6 (2 pilots, navigator, radar navigator, electronic warfare operator, gunner)
ENGINES
B-52G: 8 Pratt & Whitney J57-P-43W
turbojet
B-52H: 8 Pratt & Whitney TF33-
P-3/P-103 turbofan maxpower J57: 13,750 Ib (6,237 kg) static thrust each
TF33: 17,000 Ib (7,718
kg) static thrust each
internalfuel capacity
46,000 US gal (174,130
liters)
WEIGHTS
empty 195,000 Ib (88,450 kg)
max bomb load
60,000 Ib (27,216 kg) max long-range weapons load
43,500 Ib (19,731 kg) max takeoff 488,000 Ib (221,350 kg) max with in-flight refueling
566,000 Ib (256,783 kg)
DIMENSIONS
wingspan 185 ft (56.39 m)
length 157 ft 7 in (48.03 m)
height 40 ft 8 in (12.4 m)
wing area 4,000 ft2 (372 m2)
PERFORMANCE
max speed at altitude
516 kts (595 mph; 957
km/h) or Mach 0.90
cruise speed at altitude
442 kts (509 mph; 819 km/h) or Mach 0.77 penetration speed at low altitude
352-365 kts (405-420 mph; 652-676 km/h)
or Mach 0.53-0.55
takeoff’run 9,500 ft (2,895 m)
ceiling 55,000 ft (16,775 m) range B-52G with 30,000-lb
(13,608-kg) internal payload, no loiter: no refueling, approx 6,200 nm (7,139 mi; 11,482 km); 1
refueling, approx 7,800 nm (8,982 mi; 14,446 km)
| B-52H: 8,800 nm (10,133 | or!2AGM-129ACM | |
| mi; 16,306 km) | or 4 gravity nuclear | |
| armament I 20-mm Vulcan M61A1 | bombs in weapons bay | |
| gun with 1,242 rounds | and 12 SRAM or ALCM | |
| in tail turret | on wing pylons | |
| max internal conventional | (approx 70 B-52G are | |
| bomb load consists of: | fitted with AGM-84 | |
| 27250/500/750-lb | Harpoon antiship | |
| (113/227/340-kg) | missiles) | |
| or 8 2,000-lb (907-kg) | radar | AN/ASQ-38 bombing/ |
| bombs | navigation | |
| external payloads: | AN/ASG-15 turret | |
| 24250/500/750-lb | control system | |
| (113/227/340-kg) | AN/ALQ-172 Pave Mint | |
| bombs | ESM | |
| or 10 2,000-lb (907-kg) | AN/ALQ-153 pulse- | |
| bombs | Doppler tail-warning | |
| nuclear weapons payload | AN/ALQ:155(V) ECM | |
| consists of: | suite | |
| up to 20 AGM-69A | AN/ALT-1 6 jammer | |
| SRAM | AN/ALE-29 chaff | |
| or 12 AGM-86B ALCM | dispensers |
