5 August 1954: The first production Boeing B-52A Stratofortress, B-52A-1-BO 52-001, made its first flight from Boeing Field, Seattle, Washington.
The B-52A differed from the XB-52 and YB-52 in that its cockpit was arranged for side-by-side seating, rather than the B-47-type tandem arrangement of the prototypes. It also had an inflight refueling system allowing it to receive fuel from an airborne KC-97 tanker.
52-001 was used as a service test aircraft along with sister ships 52-002 and 52-003. It was used to test the shorter vertical fin of the B-52G. It was permanently grounded at Chanute Air Force Base in the early 1960s.
13 July 1968: The first production General Dynamics FB-111A supersonic strategic bomber successfully completed a 30-minute maiden flight at Carswell Air Force Base, Fort Worth, Texas. The FB-111A differed from the F-111A fighter bomber with the substitution of a larger wing, originally designed for the F-111B, giving the bomber a 7 foot (2.134 meter) increase in wingspan. The landing gear was strengthened, the bomb bay enlarged, and it had more powerful engines.
The airplane’s very long nose earned the nickname “Aardvark,” but this did not become official until 1996.
67-0159 was delivered to the U.S. Air Force 4 September 1968 and assigned to the Air Force Flight Test Center, Edwards Air Force Base, California. (The first six production airplanes were used for flight testing.)
67-0159 was later converted to the F-111G configuration. In 1980 it was sent to the Sacramento Air Logistics Center to test weapons modifications and received a spectacular white and orange paint scheme. It was retired in 1990. 67-0159 is in the collection of the National Museum of the United States Air Force. It is on loan and now on display at the Aerospace Museum of California, Sacramento, California.
The General Dynamics FB-111A is a two-place, twin-engine, strategic bomber with variable-sweep wings, assigned to the Strategic Air Command. It is 73.54 feet (22.415 meters) long. The wingspan varies from a maximum 70.0 feet (21.336 meters) when fully extended, and a minimum 33.96 feet (10.351 meters) when swept fully aft. Overall height is 17.04 feet (5.194 meters).
The wings of the FB-111A have a total area of 550 square feet (51.10 square meters). When fully extended, the wings’ leading edges are swept aft to 16.0°. The angle of incidence at the root is +1° and -3° at the tip. There is 1.0° dihedral.
The Aardvark’s empty weight is 47,481 pounds (21,537 kilograms). Normal maximum takeoff weight is 116,115 pounds (52,669 kilograms), and the maximum overload takeoff weight is or 119,243 pounds (54,088 kilograms).
The aircraft is powered by two Pratt & Whitney TF30-P-107 engines. This is a two-spool axial-flow turbofan engine with afterburner. It has a 3-stage fan section, 13-stage compressor section (6 low- and 7 high-pressure stages) and 4-stage turbine (1 high- and 3 low-pressure stages). The -107 has a maximum continuous power rating of 10,800 pounds of thrust (48.041 kilonewtons) at 14,150 r.p.m., N2 (static thrust, at Sea Level), and a maximum power rating of 20,350 pounds (90.521 kilonewtons) at 14,550 r.p.m., N2 (45 minute limit) The T30-P-107 is 3 feet, 2.12 inches (0.968 meters) in diameter, 20 feet, 1.4 inches (6.132 meters) long, and weighs 4,121 pounds (1,869 kilograms).
The FB-111A has an average cruise speed of 415–442 knots (478–509 miles per hour/769-819 kilometers per hour), depending on the mission profile. It’s maximum speed at 50,000 feet (15,240 meters) is 1,262 knots (1,452 miles per hour/2,337 kilometers per hour)—Mach 2.20. The bomber’s service ceiling varies from 50,390 feet to 56,380 feet (15,359–17,185 meters), again, depending on the mission profile. The maximum combat range is 4,920 nautical miles (5,662 statute miles/9,112 kilometers). The airplane can carry as many as six 600 gallon (2,271 liter) external tanks on underwing pylons. This gives the Aardvark a maximum ferry range of 4,313 nautical miles (4,963 statute miles/7,988 kilometers).
The FB-111A could carry weapons in an internal bomb bay or on underwing hardpoints. It could be armed with up to 37,500 pounds (17,010 kilograms) of conventional bombs; or six AGM-69A Short Range Attack Missiles (SRAM). The Aardvark could carry maximum of six nuclear weapons (B-43, B-57 or B-61).
In addition to a prototype (63-9783, which was converted from the last production F-111A) General Dynamics built 76 FB-111A strategic bombers. With the introduction of the Rockwell B-1B Lancer, the FB-111As remaining in service were converted to F-111G tactical fighter bombers. They were retired by 2003.
The Royal Australian Air Force bought 15 of the F-111Gs. By 2007, these had also been taken out of service.
29 June 1955: The first operational Boeing B-52 Stratofortress, RB-52B-15-BO 52-8711, was delivered to the 93rd Bombardment Wing, Heavy, at Castle Air Force Base, Merced, California. The new long-range heavy bomber would replace the 93rd’s Boeing B-47 Stratojets.
Fifty B-52Bs were built by Boeing at its Plant 2, Seattle, Washington. Twenty-seven of these were RB-52B reconnaissance bombers. They were designed to accept a pressurized electronic intelligence and photographic reconnaissance capsule with a two-man crew that completely filled the bomb bay. Without the capsule aboard, the RB-52s were capable of the same bombing missions as their sister B-52Bs. The change could be made within a few hours.
The B-52B/RB-52B was operated by a six-man flight crew for the bombing mission, and eight for reconnaissance. These were the aircraft commander/pilot, co-pilot, navigator, radar navigator/bombardier, electronic warfare officer, and gunner, plus two reconnaissance technicians when required.
The airplane was 156.6 feet, (47.7 meters) long with a wingspan of 185.0 feet (56.4 meters) and overall height of 48.3 feet (14.7 meters). The wings were mounted high on the fuselage (“shoulder-mounted”) to provide clearance for the engines which were suspended on pylons. The wings’ leading edges were swept aft to 36° 54′. Their angle of incidence was 6° and there was 2° 30′ dihedral. The RB-52B’s empty weight was 162,969 pounds (73,921 kilograms), with a combat weight of 257,900 pounds (116,981 kilograms) and a maximum takeoff weight of 390,000 pounds (176,901 kilograms). (MTOW was later increased to 420,000 pounds.)
Early production B-52Bs were powered by eight Pratt & Whitney J57-P-1W turbojet engines, while later aircraft were equipped with J57-P-19W and J57-P-29W or WA turbojets. The engines were grouped in two-engine pods on four under-wing pylons. The J57 was a two-spool, axial-flow engine with a 16-stage compressor section (9 low- and 7-high-pressure stages) and a 3-stage turbine section (1 high- and 2 low-pressure stages). The J57-PW-1 engines had a Normal Power rating of 8,250 pounds of thrust (32.698 kilonewtons) at 9,720 r.p.m., N1, continuous; Military Power, 9,500 pounds thrust (42.258 kilonewtons) at 9,950 r.p.m., N1, for 30 minutes; and Maximum Power, 11,100 pounds of thrust (49.375 kilonewtons) with water injection, at 9,950 r.p.m., N1, 5 minute limit. The J57-PW-1 was 3 feet. 4.5 inches (1.029 meters) in diameter, 13 feet, 1.2 inches (3.993 meters) long, and weighed 4,210 pounds (1,910 kilograms).
The B-52B/RB-52B had a cruise speed of 517 knots (595 miles per hour/957 kilometers per hour) at 35,000 feet (10,668 meters). The maximum speed was 542 knots (624 miles per hour/1,004 kilometers per hour) at 19,500 feet (5,944 meters). The service ceiling at combat weight was 47,600 feet (14,508 meters).
The RB-52B had a maximum fuel capacity of 37,385 gallons (141,518 liters). Its maximum ferry range was 6,460 nautical miles (7,434 statute miles/11,964 kilometers). With a 10,000 pound (4,536 kilogram) bomb load, the RB-52B had a combat radius of 3,110 nautical miles (3,579 miles/5,760 kilometers). With inflight refueling, the bomber’s range was world-wide.
Defensive armament consisted of four Browning Aircraft Machine Guns, Caliber .50, AN-M3, mounted in a tail turret with 600 rounds of ammunition per gun. These guns had a combined rate of fire of 4,800 rounds per minute.
The B-52B could carry twenty-seven 750 pound (340 kilogram) bombs, or two 25,000 pound (11,340 kilogram) Special Weapons (thermonuclear bombs).
Boeing manufactured 744 B-52 Stratofortress bombers, with the final one rolled out at Wichita, Kansas, 22 June 1962. As of June 2016, 75 B-52H bombers remain in service with the United States Air Force.
RB-52B 52-8711 remained in active service until 29 September 1965. Today it is on display at the Strategic Air and Space Museum, Ashland, Nebraska.
24 June 1993: In compliance with an arms control treaty between the United States and the Soviet Union, the Aerospace Maintenance and Regeneration Center (AMARC) at Davis-Monthan Air Force Base, Tucson, Arizona, immediately began the destruction of 363 Boeing B-52 Stratofortress strategic bombers.
22 June 1962: The last of 744 Boeing B-52 Stratofortress strategic bombers, B-52H-175-BW, serial number 61-0040, was rolled out at the Boeing Military Airplane Company plant in Wichita, Kansas.
The U.S. Air Force contracted 62 B-52H Stratofortresses, serial numbers 60-0001 through 60-0062, on 6 May 1960. A second group of 40, serials 61-0001 through 61-0040, were ordered later. All were built at the Boeing Wichita plant.
The B-52H, like the B-52G, is a re-engineered aircraft, structurally different from the XB-52, YB-52, and B-52A–B-52F Stratofortress variants. It is lighter, carries more internal fuel, giving it a longer unrefueled range, and is strengthened for low-altitude flight. The shorter vertical fin is intended to prevent the losses caused by the original tall fin in turbulent air. The B-52H is equipped with quieter, more efficient turbofan engines.
The B-52H was developed to carry four Douglas GAM-87 Skybolt air-launched ballistic missiles on pylons mounted under the wings, inboard of the engines. The Skybolt was armed with a 1-megaton W-59 thermonuclear warhead. The program was cancelled, however, and the North American Aviation AGM-28 Hound Dog air-launched cruise missile was used instead. (Interestingly, the Hound Dog’s Pratt & Whitney J52-P-3 turbojet engine could be used to supplement the B-52’s takeoff thrust, and then refueled from the bomber’s tanks before being air-launched.)
The B-52H is a sub-sonic, swept wing, long-range strategic bomber. It was originally operated by a crew of six: two pilots, a navigator and a radar navigator, an electronic warfare officer, and a gunner. (The gunner was eliminated after 1991). The airplane is 159 feet, 4 inches (48.565 meters) long, with a wing span of 185 feet (56.388 meters). It is 40 feet, 8 inches (12.395 meters) high to the top of the vertical fin. The B-52H uses the vertical fin developed for the B-52G, which is 22 feet, 11 inches (6.985 meters) tall. This is 7 feet, 8 inches (2.337 meters) shorter than the fin on the XB-52–B-52F aircraft, but the fin’s chord is longer.
The wings of the B-52H have a total area of 4,000 square feet ( square meters). The leading edges are swept aft to 36° 58′. The angle of incidence is 6°, and there is 2° 30′ dihedral. (The wings are very flexible and exhibit pronounced anhedral when on the ground.) To limit twisting in flight, the B-52 has spoilers on top of the wings rather than ailerons at the trailing edges.
The bomber has an empty weight of 172,740 pounds (78,354 kilograms) and its Maximum Takeoff Weight (MTOW) is 488,000 pounds (221,353 kilograms).
The most significant difference between the B-52H and the earlier Stratofortresses is the replacement of the eight Pratt & Whitney J57-series turbojet engines with eight Pratt & Whitney Turbo Wasp JT3D-2 (TF33-P-3) turbofans, which are significantly more efficient. They are quieter and don’t emit the dark smoke trails of the turbojets. The TF-33 is a two-spool axial-flow turbofan engine with 2 fan stages, a 14-stage compressor section (7-stage intermediate pressure, 7-stage high-pressure) and and a 4-stage turbine (1-stage high-pressure, 3-stage low-pressure). The TF33-P-3 has a maximum continuous power rating of 14,500 pounds of thrust (64.499 kilonewtons) at 9,750 r.p.m., N1. Military Power, limited to 30 minutes, is 16,500 pounds (73.396 kilonewtons) at 10,000 r.p.m., N1. Each engine produces a maximum of 17,000 pounds of thrust (75.620 kilonewtons) at 10,050 r.p.m., N1, with a 5-minute limit. The TF33-P-3 is 11 feet, 4.32 inches (3.4625 meters) long, 4 feet, 4.93 inches (1.3442 meters) in diameter and weighs 3,900 pounds (1,769 kilograms).
The B-52H has a cruise speed of 456 knots (525 miles per hour/845 kilometers per hour). It has a maximum speed, with Military Power, of 555 knots (639 miles per hour/1,028 kilometers per hour) at 20,700 feet (6,309 meters)—0.906 Mach. The service ceiling is 46,900 feet (14,295 meters). The unrefueled range is 8,000 miles (12,875 kilometers). With inflight refueling, its range is limited only by the endurance of its crew.
The B-52H can carry a wide variety of conventional free-fall or guided bombs, land-attack or anti-ship cruise missiles, and thermonuclear bombs or cruise missiles. These can be carried both in the internal bomb bay or on underwing pylons. The bomb load is approximately 70,000 pounds (31,751 kilograms).
The B-52H was equipped with a General Electric M61 Vulcan 20 mm six-barreled rotary cannon (a “Gatling gun”) in a remotely-operated tail turret. The gun had a rate of fire of 4,000 rounds per minute, and had a magazine capacity of 1,242 rounds. After 1991, the gun and its radar system were removed from the bomber fleet. The flight crew was reduced to five.
102 B-52Hs were built by Boeing Wichita. Beginning in 2009, eighteen B-52H bombers were placed in climate-controlled long term storage at Tinker Air Force Base, Oklahoma. In 2014, the entire fleet began a major avionics upgrade. As of December 2015, fifty-eight of the bombers remained in the active fleet of the United States Air Force and eighteen are assigned to the Air Force Reserve.
Recently, a B-52H-156-BW Stratofortress, 61-0007, Ghost Rider, was returned to operational status after eight years in storage at Davis-Monthan Air Force Base, Tucson, Arizona. 45,000 man-hours were required to restore the bomber.
The B-52H is expected to remain in service until 2040.
58 years after roll-out, 61-0040 is still in service with the United States Air Force, assigned to the 23rd Bomb Squadron, 5th Bomb Wing, at Minot Air Force Base, North Dakota.