Daily Archives: February 12, 2017

12 February 1959

Convair B-36J-10-CF Peacemaker, 52-2827, the last B-36 built. (U.S. Air Force)
Convair B-36J-75-CF Peacemaker, 52-2827, the last B-36 built. (U.S. Air Force)

The Last Peacemaker: This gigantic airplane, a Convair B-36J-75-CF Peacemaker, serial number 52-2827, was the very last of the ten-engine strategic bombers built by the Convair Division of General Dynamics at Fort Worth, Texas. It was completed 1 July 1954. On 14 August, it was delivered to the Strategic Air Command, 92nd Bombardment Wing, Heavy, at Fairchild Air Force Base, Washington. Later, 52-2827 was assigned to the 95th Bombardment Wing, Heavy, at Biggs Air Force Base, El Paso, Texas.

The last one built, 52-2827 was also the last operational B-36.

Convair B-36J-10-CF Peacemaker 52-2827 at Amon Carter Field, Fort Worth, Texas, 12 February 1959. (Unattributed)
Convair B-36J-75-CF Peacemaker 52-2827 at Amon Carter Field, Fort Worth, Texas, 12 February 1959. (Unattributed)

On 12 February 1959, after 4 years, 5 months, 30 days service, the Air Force returned the bomber to Fort Worth. 52-2827 departed Biggs Air Force Base at 11:00 a.m., under the command of Major Frederick J. Winter, with 23 persons on board. It touched down at Amon Carter Field at 2:55 p.m.

After a ceremony attended by thousands, the bomber was officially retired. It was then put on display at Amon Carter Field.

After decades of neglect, the bomber was placed in the care of the Pima Air and Space Museum at Tucson for restoration and display.

The last Peacemaker, Convair B-36J-10-CF 52-2827, comes to the end of the assembly line at Fort Worth, Texas. (University of North Texas Libraries)
The last Peacemaker, Convair B-36J-75-CF 52-2827, comes to the end of the assembly line at Fort Worth, Texas. (University of North Texas Libraries)

Convair B-36J 52-2827 is one of 14 “Featherweight III” high altitude variants. It was built without the six retractable defensive gun turrets of the standard B-36, retaining only the two M24A1 20 mm autocannons in the tail. This reduced the crew requirement to 13. It is 162 feet, 1 inch (49.403 meters) long with a wingspan of 230 feet (70.104 meters) and overall height of 46 feet, 9 inches (14.249 meters). The empty weight is 166,125 pounds (75,353 kilograms) and loaded weight is 262,500 pounds (119,068 kilograms). Maximum takeoff weight is 410,000 pounds (185,973 kilograms).

The B-36J has ten engines. There are six air-cooled, supercharged 4,362.49 cubic-inch-displacement (71.488 liter) Pratt & Whitney Wasp Major C6 (R-4360-53) four-row, 28-cylinder radial engines placed inside the wings in a pusher configuration. These had a compression ratio of 6.7:1 and required 115/145 aviation gasoline. The R-4360-53 had a Normal Power rating of 2,800 horsepower at 2,600 r.p.m. Its Military Power rating was 3,500 horsepower at 2,800 r.p.m., and 3,800 horsepower at 2,800 r.p.m. with water injection—the same for Takeoff. The engines turned three-bladed Curtiss Electric constant-speed, reversible propellers with a diameter of 19 feet, 0 inches (5.791 meters) through a 0.375:1 gear reduction. The R-4360-53 is 9 feet, 9.00 inches (2.972 meters) long, 4 feet, 7.00 inches (1.397 meters) in diameter, and weighs 4,040 pounds (1,832.5 kilograms).

Four General Electric J47-GE-19 turbojet engines are suspended under the wings in two-engine pods. The J47 is a  single-shaft axial-flow turbojet engine with a 12-stage compressor section, 8 combustion chambers, and single-stage turbine. The J47-GE-19 was modified to run on gasoline and was rated at 5,200 pounds of thrust (23.131 kilonewtons).

The B-36J Featherweight III had a cruise speed of 230 miles per hour (370 kilometers per hour) and a maximum speed of 418 miles per hour (673 kilometers per hour). The service ceiling was 43,600 feet (13,289 meters) and its combat radius was 3,985 miles (6,413 kilometers). The maximum range was 10,000 miles (16,093 kilometers).

The B-36 was designed during World War II and nuclear weapons were unknown to the Consolidate-Vultee Aircraft Corporation engineers. The bomber was built to carry up to 86,000 pounds (39,009 kilograms) of conventional bombs in the four-section bomb bay. It could carry the 43,600 pound (19,777 kilogram) T-12 Cloudmaker, a conventional explosive earth-penetrating bomb. When armed with nuclear weapons, the B-36 could carry several Mk.15 3.8 megaton thermonuclear bombs. By combining the bomb bays, one Mk.17 15-megaton thermonuclear bomb could be carried.

Bomb, Mark 17, displayed with Convair B-36J Peacemaker at the National Museum of the United States Air Force. (U.S. Air Force)
Bomb, Mark 17 Mod 2, displayed with Convair B-36J Peacemaker at the National Museum of the United States Air Force. (U.S. Air Force)

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

Convair B-36J-10-CF 52-2827 at the Pima Air and Space Museum, Tucson, Arizona. (B-36 Peacemaker Museum)
Convair B-36J-75-CF 52-2827 at the Pima Air & Space Museum, Tucson, Arizona. (B-36 Peacemaker Museum)

© 2017, Bryan R. Swopes

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12 February 1935

USS Macon (ZRS-5) recovering two Curtiss F9C Sparrowhawk scout biplanes. (U.S. Navy)
USS Macon (ZRS-5) recovering two Curtiss F9C Sparrowhawk scout biplanes. (U.S. Navy)

12 February 1935: The United States Navy rigid airship USS Macon (ZRS-5), under the command of Lieutenant Commander Herbert Victor Wiley, crashed into the Pacific Ocean off Monterey Bay, on the central California coastline. The airship soon sank to the sea floor, approximately 1,500 feet (457 meters) below. Of the crew of 76 men, 74 survived.

Captain Herbert Victor Wiley, United States Navy

Lieutenant Commander Wiley was a 1915 graduate of the United States Naval Academy, Annapolis, Maryland. He had previously served aboard the U.S. Navy’s first rigid airship, USS Shenandoah (ZR-1) and then commanded USS Los Angeles (ZR-3), 1929–1930. He had been assigned as executive officer of USS Akron (ZRS-4) and had been one of only 3 crew members to survive the wreck of that airship off the coast of New Jersey, 4 April 1933. He took command of USS Macon in June 1934. During World War II, Captain Wiley commanded Destroyer Squadron 29 (consisting of thirteen Clemson-class “flush-deck” destoyers) with the Aisatic Fleet, and later, the Colorado-class battleship USS West Virginia (BB-48). He rose to the rank of rear admiral before retiring in 1947.

USS Macon was built by the Goodyear-Zeppelin Corporation at Akron, Ohio. It was launched 21 April 1933, and commissioned 23 June 1933.

USS Macon (ZRS-5) under construction at the Goodyear Airdock, Akron, Ohio, 1933. (U.S. Navy)

Macon was constructed of duralumin ring frames and girders, covered with a fabric envelope. The rigid airship was 785 feet (239.3 meters) long with a maximum diameter of 132 feet, 10 inches (40.488 meters). The overall height was 146 feet, 2 inches (44.552 meters). The airship displaced 7,401,260 cubic feet of air (209,580 cubic meters). Lift was provided by 6,500,000 cubic feet (184,060 cubic meters) of non-flammable helium gas contained in 12 rubberized fabric gas cells.

Macon had a dead weight of 108.2 tons (98,157 kilograms) and a useful lift of 160,644 pounds (72,867 kilograms).

Maybach VL-2 60° V-12 in the collection of the National Air and Space Museum. (NASM)

Propulsion was provided by eight water-cooled, fuel-injected, 33.251 liter (2,029.077-cubic-inch-displacement) Maybach VL-2 overhead valve 60° V-12 gasoline engines producing a maximum 570 horsepower at 1,600 r.p.m., each, or 450 horsepower at 1,400 r.p.m. for cruise. In addition to gasoline, the VL-2 could also use blau gas (similar to propane) as fuel. The engines were reversible and drove Allison Engineering Co. out-drives, which turned three-bladed fixed-pitch, rotatable propellers. The VL-2 is 6 feet, 5 inches (1.96 meters) long, 3 feet, 0 inches (0.91 meters) wide and 3 feet, 2 inches (0.97 meters) high. It weighs 2,530 pounds (1,148 kilograms).

The airship had a maximum speed of 75.6 knots (87.0 miles per hour, 140.0 kilometers per hour).

USS Macon was armed with eight Browning .30-caliber machine guns for defense. It also carried five Curtiss-Wright Airplane Division F9C-2 Sparrowhawk reconnaissance airplanes in an internal hangar bay. These were small single-place, single-engine biplanes, with a length of 20 feet, 7 inches (6.274 meters) and wingspan of 25 feet, 5 inches (7.747 meters). The Sparrowhawk had an empty weight of 2,114 pounds (959 kilograms) and loaded weight of 2,776 pounds (1,259 kilograms).

The F9C-2 was powered by an air-cooled, supercharged, 971.930-cubic-inch displacement (15.927 liter) Wright Aeronautical Division Whirlwind R-975E-3 (R-975-11, -24 or -26) nine-cylinder radial engine with a compression ratio of 6.3:1. The R-975E-3 had a normal power rating of 420 horsepower at 2,200 r.p.m., and 440 to 450 horsepower at 2,250 r.p.m. for takeoff, depending on variant. These were direct drive engines which turned two-bladed propellers. They were 3 feet, 7.00 inches to 3 feet, 7.47 inches (1.092–1.104 meters) long, 3 feet, 11 inches to 3 feet, 11.25 inches (1.143–1.149 meters) in diameter, and weighed from 660 to 700 pounds (299–317.5 kilograms).

The Sparrowhawk had a maximum speed of 176 miles per hour (283 kilometers per hour), a range of 297 miles (478 kilometers) and a service ceiling of 19,200 feet (5,852 meters).

The airplane was armed with two fixed Browning .30-caliber machine guns, synchronized to fire forward through the propeller arc.

Four of Macon‘s fighters, Bureau of Aeronautics serial numbers A9058–A9061, were lost when the airship went down.

Curtiss F9C-2 Sparrowhawk, Bu. No. 9056. (U.S. Navy)
Curtiss-Wright F9C-2 Sparrowhawk, Bu. No. A9056. (U.S. Navy)

During an earlier transcontinental flight, USS Macon had encountered severe turbulence while crossing mountains in Arizona. A diagonal girder in one of the ring frames failed. Temporary repairs were made, but permanent repairs were deferred until the next scheduled overhaul.

On 12 February 1935, the airship flew into a storm near Point Sur, California. The ring frame failed and the upper vertical fin was lost. Pieces of broken girders punctured several of the aft helium cells.

With the loss of helium, Macon lost rear buoyancy and began to settle. To compensate, all engines were run at full power and ballast was released. The airship began to climb with a nose-up pitch angle. When it passed 2,800 feet (853.4 meters) altitude, it reached its Pressure Altitude Limit. At this point, expanding helium began to vent from the gas cells. Macon continued rising until reaching 4,850 feet (1,478.3 meters), by which time it had lost so much helium that the engines could no longer keep it airborne and it again began to settle toward the ocean’s surface. The descent took twenty minutes.

One sailor jumped from the airship, but did not survive the fall. Another swam back to the sinking ship to collect personal belongings and drowned. The rest of the crew was rescued by the light cruiser USS Richmond (CL-9).

USS Macon was the U.S. Navy’s last rigid airship. For the next twenty years, all lighter-than-air craft were non-rigid “blimps”.

USS Macon (ZRS-5) is seen from directly below as it passes over San Diego, California, 9 February 1934. (U.S. Navy)
USS Macon (ZRS-5) is seen from directly below as it passes over San Diego, California, 9 February 1934. (U.S. Navy)

© 2017, Bryan R. Swopes

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