Tag Archives: Reconnaissance Bomber

8 August 1946

Convair XB-36 Peacemaker 42-13570 engine run-up
The prototype Consolidated-Vultee XB-36, 42-13570, stands at the end of the runway with all six engines running. (U.S. Air Force)

8 August 1946: At Fort Worth, Texas, the Consolidated-Vultee Aircraft Corporation XB-36 prototype, 42-13570, made its first flight. Convair test pilots Beryl Arthur Erickson and G.S. “Gus” Green, along with Chief Flight Test Engineer James D. “J.D.” McEachern, were in the cockpit. Six other crew members were aboard.

Chief Test Pilot Beryl Arthur Erickson. (Convair)

In a 1992 interview published in Code One Magazine, Erickson said that he and his crew had been ready to take off at 5 a.m., but they didn’t get their release until noon. The Texas summer temperature was 100 degrees (37.8 °C.), but inside the cockpit, the temperature was 140° F. (60 °C.) The engines were overheating and the oil pressure was low. When they pushed the throttles forward, the XB-36 accelerated smoothly and lifted off at 110 knots (126.6 miles per hour, 203.7 kilometers per hour). The retired test pilot said, “The XB-36 controlled nicely in the takeoff run and in the transition to steady climb. We flew conservatively with the gear down. The flight was uneventful and lasted thirty-eight minutes.”

Chief Test Pilot Beryl Arthur Erickson at the aircraft commander’s station of the Consolidated-Vultee XB-36 long-range heavy bomber. (Code One).

The B-36 was the largest and heaviest airplane built up to that time. It was designed as a long-range heavy bomber, able to reach targets on the European continent from the United States and return, should England fall to Nazi Germany during World War II. With the end of the war, its purpose was changed to that of a long range strategic bomber, carrying large nuclear weapons that weren’t even imagined when the design process had begun.

A size comparison between the Convair XB-36 prototype and a Boeing B-29 Superfortress.
A size comparison between a Boeing B-29-55-BA Superfortress, 44-84017, and the Consolidated-Vultee XB-36 prototype. (U.S. Air Force)

The XB-36 had a wing span of 230 feet (70.104 meters), nearly 90 feet longer than that of the B-29 Superfortress that it would replace. It was 162 feet, 1 inch (49.403 meters) long and 46 feet, 8 inches (14.224 meters) to the tip of the vertical fin. The prototype’s empty weight was 131,740 pounds (59,756 kilograms), and it had a maximum gross weight of 276,506 pounds (125,421 kilograms).

The XB-36 was powered by six air-cooled, supercharged, 4,362.49 cubic-inch-displacement (71.489 liter) Pratt & Whitney Wasp Major TSB1P-G (R-4360-25) 28-cylinder four-row radial engines, with a normal power rating of 2,500 horsepower at 2,550 r.p.m. to 5,000 feet (1,524 meters), and 3,000 horsepower at 2,700 r.p.m. for takeoff. They were mounted inside the wings. The engines were arranged in a “pusher” configuration with intake and cooling air entering through inlets in the wing leading edge. They drove three-bladed propellers with a diameter of 19 feet (5.8 meters) through a 0.381:1 gear reduction. The R-4360-25 was 9 feet, 1.75 inches (2.788 meters) long 4 feet, 4.50 inches (1.334 meters) in diameter, and weighed 3,483 pounds (1,580 kilograms).

The airplane’s maximum speed was 346 miles per hour (557 kilometers per hour) and cruising speed was 216 miles per hour (348 kilometers per hour). It had an estimated range of 9,500 miles (15,290 kilometers) with a 10,000 pound (4,536 kilogram) bomb load.

The prototype Convair XB-36, 42-13570, lifts off the runway at Fort Worth, Texas. (U.S. Air Force)
The prototype Consolidated-Vultee XB-36, 42-13570, lifts off the runway at Fort Worth, Texas. (U.S. Air Force)

After testing, improvements were incorporated into the second prototype, YB-36 42-13571. In June 1948, the XB-36 was modified with R-4360-41 engines, and the main landing gear was changed from a single-wheel design to a 4-wheel bogie. With these and other changes the XB-36 was redesignated YB-36A. It was used for continued testing for the next several years, but was eventually stripped of its engines and equipment and used for firefighter training at the adjacent Carswell Air Force Base.

The YB-36 was selected for production as the B-36A Peacemaker. The B-36 series was produced in both bomber and reconnaissance versions and was in front line service from 1949 to 1959. Beginning with the B-36D, four turbojet engines were mounted beneath the wings in pods similar to those on the Boeing B-47 Stratojet, greatly increasing the bomber’s performance. A total of 384 were built. Only five still exist. The Peacemaker was never used in combat.

The Convair XB-36 in flight. (U.S. Air Force)
The Consolidated-Vultee XB-36, 42-13570, in flight. (U.S. Air Force)

© 2018, Bryan R. Swopes

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29 June 1955

The first operational Boeing B-52 Stratofortress, RB-52B-15-BO 52-8711. (U.S. Air Force)
The first operational Boeing B-52 Stratofortress, RB-52B-15-BO 52-8711. (U.S. Air Force)

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.

Pressurized two-man RB-52 reconnaissance pod.
Pressurized two-man RB-52 reconnaissance pod. (U.S. Air Force)

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.)

The bomb bay of this RB-52B-10-BO Stratofortress, 52-012, is open, revealing the reconnaissance pod. (U.S. Air Force)

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).

Boeing RB-52B-10-BO Stratofortress 52-013. (U.S. Air Force)

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.

Tail gun turret of an early B-52 Stratofortress
B-52 tail gun turret

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.

A Strategic Air Command alert crew runs to man their bomber, Boeing RB-52B-15-BO Stratofortress 52-8711, 22 Bombardment Wing (Heavy), the first operational B-52, at March Air Force Base, California, 1965. (U.S. Air Force)
A Strategic Air Command alert crew runs to man their bomber, Boeing RB-52B-15-BO Stratofortress 52-8711, 22 Bombardment Wing (Heavy), the first operational B-52, at March Air Force Base, California, 1965. (U.S. Air Force)

© 2019, Bryan R. Swopes

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