Tag Archives: Strategic Air Command

26 June 1948

Convair B-36A-1-CF (S/N 44-92004, the first -A model built) in flight. (U.S. Air Force photo)
Convair B-36A-1-CF 44-92004, the first B-36A built. (U.S. Air Force)

26 June 1948: The 7th Bombardment Wing, Very Heavy, at Carswell Air Force Base, Fort Worth, Texas, received the United States Air Force’s first Consolidated-Vultee Aircraft Corporation (“Convair”) B-36A, a six-engine, very long range heavy bomber. Its mission was to serve as a nuclear-capable deterrent until the Boeing B-52 Stratofortress came into service five years later. A total of 22 B-36As were delivered by February 1949. These were not armed and were used for crew training. Most were later converted by Convair to RB-36E reconnaissance bombers, beginning in 1950.

The B-36A differed from the XB-36 prototype in several areas, but two features were the most apparent: The cockpit had been completely revised and now covered by a large dome. The single-wheel main landing gear was replaced by four-wheel bogies to better spread the airplane’s weight over the runway surface.

A crew of thirteen airmen with their Convair B-36A-10-CF Peacemaker, 44-92014. (LIFE Magazine via Jet Pilot Overseas)
A crew of thirteen airmen with their Convair B-36A-10-CF Peacemaker, 44-92013, at Carswell AFB, 1949. (LIFE Magazine via Jet Pilot Overseas)

The B-36A was 162.1 feet (49.4 meters) long with a wingspan of 230.0 feet (70.1  meters) and overall height of 46.8 feet (14.3 meters). The wings had 2° dihedral, an angle of incidence of 3° and -2° twist. The wings’ leading edges were swept aft to 15° 5′. The airplane’s total wing area was 4,772 square feet (443.33 square meters). Its empty weight was 135,020 pounds (61,244 kilograms). The combat weight was 212,800 pounds (96,524 kilograms) and maximum takeoff weight (MTOW) was 310,380 pounds (140,786 kilograms).

Convair B-36A 44-92015 at Carswell Air Force Base.

The initial production version of the Peacemaker was powered by six air-cooled, supercharged, 4,362.5 cubic-inch-displacement (71.489 liter) Pratt & Whitney Wasp Major R-4360 Pusher (R-4360-25) four-row, 28-cylinder radial engines rated at 2,500 horsepower at 2,550 r.p.m. at 37,000 feet (11,278 meters), and 3,000 horsepower at 2,700 r.p.m. for takeoff. Each engine drove a 19-foot (5.791 meter) three-bladed propeller through a 0.381:1 gear reduction. The R-4360-25 was 9 feet, 1.75 inches (2.788 meters) long and 4 feet, 4.50 inches (1.334 meters) in diameter. It weighed 3,483 pounds (1,580 kilograms).

Convair B-36A 44-92015

The six radial engines gave the bomber a maximum speed of 300 knots (345 miles per hour/556 kilometers per hour) at 31,600 feet (9,632 meters). It took 53 minutes for the giant airplane to climb to an altitude of 20,000 feet (6,396 meters). The service ceiling for the B-36A was 39,100 feet (11,918 meters), and combat ceiling was 35,800 feet (10,912 meters). The ferry range was 9,136 miles (14,702 kilometers).

The B-36As initially carried no defensive armament. The maximum bomb load was seventy-two 1,000 pound bombs (total, 72,000 pounds/32,659 kilograms) carried in four internal bomb bays. With a bomb load of 10,000 pounds (4,536 kilograms), the B-36A had a combat radius of 3,370 nautical miles (3,878 miles/6,241 kilometers).

Designed during World War II when nuclear weapons were unknown to aeronautical engineers, the bomber was designed to carry up to 86,000 pounds (39,009 kilograms) of conventional bombs. It could carry a single 43,600 pound (19,777 kilogram) T-12 Cloudmaker, a conventional explosive earth-penetrating bomb, or, later, several Mk.15 thermonuclear bombs. By combining the bomb bays, one Mk.17 15-megaton thermonuclear bomb could be carried.

The sixteenth B-36A, 44-92020, after conversion to the RB-36E reconnaissance configuration. (U.S. Air Force)
The sixteenth B-36A, 44-92020, after conversion to the RB-36E reconnaissance configuration. (U.S. Air Force)

The RB-36E reconnaissance bomber carried a crew of 22. The radial engines were upgraded to R-4360-41s which increased takeoff horsepower with water injection to 3,500 at 2,700 r.p.m. at Sea Level. Four General Electric J47-GE-19 turbojet engines were added in two two-engine pods at the outer end of each wing. These changes significantly increased the airplane’s maximum speed and altitude capability and reduced the required takeoff distance by 25%. Fourteen reconnaissance cameras were installed. There were four additional radomes on the belly and numerous external antennas for electronic intelligence gathering.

The empty weight of the RB-36E increased to 164,238 pounds (74,497 kilograms) and the maximum takeoff weight to 370,000 pounds (167,829 kilograms).

The maximum speed of the RB-36E was 363 knots (418 miles per hour/672 miles per hour) at 38,200 feet (11,643 meters). Its service ceiling was 46,400 feet (14,143 meters).

The reconnaissance bomber carried eighty 188 pound (85.3 kilogram) T-56 photo flash bombs. Defensive armament consisted of sixteen M24A1 20 mm autocannon in five remotely-operated turrets. 9,200 rounds of ammunition were carried.

Between 1946 and 1954, 384 B-36 Peacemakers were built. They were never used in combat. Only five still exist.

The first Consolidated-Vultee B-36A, 44-92004, was flown to Wright Field, Dayton, Ohio, for structural testing. Redesignated YB-36A, it was tested to destruction.

Convair YB-36 (B-36A) 004 under structural testing at Wright Field. (U.S. Air Force)
Convair YB-36A 44-92004 under structural testing at Wright Field. (U.S. Air Force)

The name, “Peacemaker,” was suggested by a Convair employee. It is a reference to the Colt Model 1873 Single-Action Army® revolver, the classic “six-shooter” of the American frontier, which is also known as the Peacemaker®.

© 2018, Bryan R. Swopes

17 June 1986

Boeing B-47E-25-DT Stratojet 52-166 is prepared to Depart NAWC China Lake. (U.S. Navy)
B-47E-25-DT Stratojet 52-166 is prepared to depart Armitage Field, NAWS China Lake, 17 June 1986. (U.S.  Air Force)

17 June 1986: After being returned to flyable condition, B-47E-25-DT Stratojet serial number 52-166, made the very last flight of a B-47 when it was flown by Major General John D. (“J.D.”) Moore and Lieutenant Colonel Dale E. Wolfe, U.S. Air Force, from the Naval Air Weapons Station China Lake in the high desert of Southern California, to Castle Air Force Base in California’s San Joaquin Valley, to be placed on static display.

52-166 had been built by the Douglas Aircraft Company at Air Force Plant No. 3, Tulsa, Oklahoma, in 1952. 52-166 had not been flown in twenty years, having sat in the Mojave Desert serving as a radar target. General Moore and Colonel Wolf were experienced B-47 pilots, though they hadn’t flown one in the same twenty years. Because the B-47 it had not been through a complete overhaul prior to the ferry flight, it was decided to leave the landing gear extended to avoid any potential problems.

During the 43 minute trip, the aircraft had several systems fail, including airspeed sensors, intercom, and partial aileron control. On approach to Castle Air Force Base, a 16 foot (4.9 meters) approach parachute was deployed. This created enough aerodynamic drag to slow the airplane while the early turbojet engines were kept operating at high power settings. These engines took a long time to accelerate from idle, making a go-around a very tricky maneuver. Releasing the chute allowed the airplane to climb out as the engines were already operating at high r.p.m.

B-47E-25-DT Stratojet 52-166 enroute Castle Air Force Base with a Lockheed T-33A Shooting Star chase. California’s Sierra Nevada Mountains are in the distance. (TSGT Michael Hagerty/U.S. Air Force)
Douglas-built B-47E-25-DT Stratojet 52-166 enroute Castle Air Force Base with a Lockheed T-33A Shooting Star chase, 17 June 1986. California’s Sierra Nevada Mountains are in the distance. (U.S. Air Force)

Designed by Boeing, the Stratojet was a high-subsonic speed strategic bomber and reconnaissance aircraft, in service from 1951 until 1977. The B-47 could fly higher and faster than jet fighters of the time, and it was also highly maneuverable. B-47E (Boeing Model 450-157-35) was flown by a two pilots in a tandem cockpit. A navigator/bombardier was at a station in the nose.

The B-47E Stratojet differed from the earlier B-47B primarily with upgraded engines and strengthened landing gear to handle an increase in maximum weight. The B-47E Stratojet is 107.1 feet (32.644 meters) long with a wingspan of 116.0 feet (35.357 meters), and an overall height of  28.0 feet (8.534 meters). The wings are shoulder-mounted and have a total area of 1,428 square feet (132.67 square meters). The wings’ leading edges are swept aft to 36° 37′. The angle of incidence is 2° 45′ and there is 0° dihedral (the wings were very flexible). The B-47E in standard configuration had an empty weight of 78,620 pounds (35,661 kilograms) and maximum takeoff weight of 200,000 pounds (90,718 kilograms).

The B-47E was powered by six General Electric J47-GE-25 turbojet engines in four nacelles mounted on pylons below the wings. This engine has a 12-stage axial-flow compressor, eight combustion chambers, and single-stage turbine. The -25 has a continuous power rating of 5,320 pounds of thrust (23.665 kilonewtons) at 7,630 r.p.m., at Sea Level; Military Power, 5,670 pounds (25.221 kilonewtons) at 7,800 r.p.m. (30 minute limit); and Maximum Power, 7,200 pounds (32.027 kilonewtons) at 7,950 r.p.m. with water/alcohol injection (5 minute limit). The J47-GE-25 has a maximum diameter of 3 feet, 1 inch (0.940 meters) and length of 12 feet, 0 inches (3.658 meters) and weighs 2,653 pounds (1,203 kilograms)

The B-47E had a maximum speed of 497 knots (572 miles per hour/920 kilometers per hour) at 20,000 feet (6,096 meters), and 485 knots (558 miles per hour/898 kilometers per hour) at 38,600 feet (11,765 meters).

The service ceiling was 31,500 feet (9,601 meters) and combat ceiling 40,800 feet (12,436 meters).

The combat radius of the B-47E was 1,780 nautical miles 2,048 miles (3,297 kilometers with a 10,000 pound (4,536 kilograms) bomb load. Ferry range with 14,720 gallons (55,721 liters) of fuel was 4,095 nautical miles (4,712 miles/7,584 kilometers).

For defense the B-47E was armed with two M24A1 20 mm autocannons with 350 rounds of ammunition per gun. The remotely-operated tail turret was controlled by the co-pilot.

The maximum bomb load of the B-47E was 12,000 pounds (5,443 kilograms). The B-47 could carry up to six 2,000 pound (907 kilogram) bombs, or one 10,670 pound (4,840 kilograms) “Special Store”: a B-41 three-stage radiation-implosion thermonuclear bomb with a yield of 25 megatons).

B-47E-25-DT Stratojet 52-166 flies over California's Central Valley farmland as it heads to Castle Air Force Base on the very last B-47 flight, 17 June 1986. (U.S. Air Force)
B-47E-25-DT Stratojet 52-166 flies over California’s Central Valley farmland as it heads to Castle Air Force Base on the very last B-47 flight, 17 June 1986. (U.S. Air Force)

A total of 2,032 B-47s were built by a consortium of aircraft manufacturers: Boeing Airplane Company, Wichita, Kansas; Douglas Aircraft Company, Tulsa, Oklahoma; Lockheed Aircraft Company, Marietta, Georgia.

The Stratojet is one of the most influential aircraft designs of all time and its legacy can be seen in almost every jet airliner built since the 1950s: the swept wing with engines suspended below and ahead on pylons. The B-47 served the United States Air Force from 1951 to 1977. From the first flight of the Boeing XB-47 Stratojet prototype, 17 December 1947, to the final flight of B-47E 52-166, was 38 years, 6 months, 1 day.

B-47E-25-DT Stratojet 52-166 on final approach to land at Castle Air Force Base, 17 June 1986. The braking chute is deployed. This is teh very last time that a B-47 flew.
Douglas-built B-47E-25-DT Stratojet 52-166 on final approach to land at Castle Air Force Base, 17 June 1986. The approach chute is deployed. This was the very last time that a B-47 flew.

© 2018, Bryan R. Swopes