19–20 November 1945: A Bell-Atlanta B-29B-60-BA Superfortress, 44-84061, named Pacusan Dreamboat, piloted by Colonel Clarence Shortridge Irvine and Lieutenant Colonel G.R. Stanley, flew non-stop and unrefueled from Guam, the largest and southernmost island in the Mariana Islands of the Western Pacific, to Washington, D.C. The four-engine heavy bomber covered the 8,198 miles (13,193 kilometers) in 35 hours, 5 minutes. It set a Fédération Aéronautique Internationale (FAI) record for Distance in a Straight Line: 12,739.59 kilometers (7,916.01 miles).¹
Pacusan Dreamboat was modified specifically for a series of long-distance flights. A standard production B-29B, a light-weight variant of the Boeing B-29 Superfortress, it did not have the four power gun turrets with their .50-caliber machine guns. A radar-directed 20 mm cannon and two .50-caliber machine guns in the tail were the only defensive weapons. Much of the standard armor plate was also deleted. It weighed 69,000 pounds (31,298 kilograms) empty and 137,000 pounds (62,142 kilograms) fully loaded. Pacusan Dreamboat was further lightened. The tail guns were removed and the tail reshaped. It had an empty weight of 66,000 pounds (29,937 kilograms). Its takeoff weight on this flight was 151,000 pounds (68,492 kilograms).
Pacusan Dreamboat carried a 12-man crew and 10,000 gallons (37,854 liters) of gasoline.
Pacusan Dreamboat set a number of distance and speed records, including Honolulu, Hawaii to Cairo, Egypt and Burbank to New York in 5 hours, 27 minutes, averaging 451.9 miles per hour (727.26 kilometers per hour).
The Pacusan Dreamboat was stricken from the Air Force inventory 8 August 1954 and reclaimed at Tinker Air Force Base, Oklahoma City, Oklahoma.
1 November 1954: The United States Air Force begins to retire the Boeing B-29 Superfortress from service. In the above photograph, B-29A-20-BN 42-94012 is at the aircraft storage facility, Davis-Monthan Air Force Base, Tucson, Arizona, “The Boneyard.” The dry desert climate and hard, alkaline soil make the base ideal for long-term aircraft storage. The Santa Catalina Mountains are in the background.
The B-29 Superfortress was the most technologically advanced—and complex—aircraft of World War II. It required the manufacturing capabilities of the entire nation to produce. Over 1,400,000 engineering man-hours had been required to design the prototypes.
The Superfortress was manufactured by Boeing at Seattle and Renton, Washington, and Wichita, Kansas; by the Glenn L. Martin Company at Omaha, Nebraska; and by Bell Aircraft Corporation, Marietta, Georgia.
There were three XB-29 prototypes, 14 YB-29 pre-production test aircraft, 2,513 B-29 Superfortresses, 1,119 B-29A, and 311 B-29B aircraft. The bomber served during World War II and the Korean War and continued in active U.S. service until 1960. In addition to its primary mission as a long range heavy bomber, the Superfortress also served as a photographic reconnaissance airplane, designated F-13, a weather recon airplane (WB-29), and a tanker (KB-29).
The B-29 was operated by a crew of 11 to 13 men. It was 99 feet, 0 inches (30.175 meters) long with a wingspan of 141 feet, 3 inches (43.068 meters). The vertical fin was 27 feet, 9 inches (8.305 meters) high. The wings had a total are of 1,720 square feet ( square meters). The angle of incidence was 4° with 4° 29′ 23″ dihderal. The leading edges were swept aft 7° 1′ 26″. The bomber’s empty weight was 71,500 pounds ( kilograms) with a maximum takeoff weight of 140,000 pounds ( kilograms).
The B-29 was powered by four air-cooled, supercharged, 3,347.66-cubic-inch-displacement (54.858 liter) Wright Aeronautical Division Cyclone 18 (also known as the Duplex-Cyclone) 670C18BA4 (R-3350-23A) two-row 18-cylinder radial engines, which had a Normal Power rating of 2,000 horsepower at 2,400 r.p.m., and 2,200 horsepower at 2,800 r.p.m. for takeoff. They drove 16 foot, 7 inch (5.055 meter) diameter, four-bladed, Hamilton Standard constant-speed propellers through a 0.35:1 gear reduction. The R-3350-23A was 6 feet, 4.26 inches (1.937 meters) long, 4 feet, 7.78 inches (1.417 meters) in diameter and weighed 2,646 pounds (1,200 kilograms).
The maximum speed of the B-29 was 353 knots (406 miles per hour/654 kilometers per hour) at 30,000 feet (9,144 meters), though its normal cruising speed was 198 knots (228 miles per hour/367 kilometers per hour) at 25,000 feet (7,620 meters). At its maximum takeoff weight, the B-29 required 1 hour, 1.5 minutes to climb from Sea Level to 20,000 feet (6,096 meters). The bomber’s service ceiling was 43,200 feet (13,167 meters). The combat range was 3,445 nautical miles (3,964 statute miles/6,380 kilometers) and its maximum ferry range was 4,493 nautical miles (5,170 statute miles/8,321 kilometers).
The Superfortress could carry a maximum of 20,000 pounds (9,072 kilograms) of bombs in two bomb bays. For defense it had 12 Browning M2 .50-caliber machine guns in four remote-controlled turrets and a manned tail position. The B-29 carried 500 rounds of ammunition per gun.
A number of B-29 Superfortresses are on display at locations around the world, but only two, the Commemorative Air Force’s B-29A-60-BN 44-62070, Fifi, and B-29-70-BW 44-69972, Doc, are airworthy. (After a lengthy restoration, Doc received its Federal Aviation Administration Special Airworthiness Certificate, 19 May 2016.)
21 September 1942: At Boeing Field, Seattle, Washington, the Boeing Model 345, the first of three XB-29 prototypes, Air Corps serial number 41-002, took off on its first flight.
Edmund T. “Eddie” Allen, Director of Aerodynamics and Flight Research, was in command, with Al Reed, Chief of Flight Test and Chief Test Pilot, as co-pilot. They climbed to 6,000 feet (1,829 meters) and began testing the XB-29’s stability and control, control power and response, and stall characteristics.
The flight was uneventful. Landing after 1 hour, 15 minutes, Allen is supposed to have said, “She flew!”
The XB-29 was 98 feet, 2 inches (29.921 meters) long with a wing span of 141 feet, 3 inches (43.053 meters), and 27 feet, 9 inches (8.458 meters) high to the top of its vertical fin. The prototype bomber had a gross weight of 105,000 pounds (47,627 kilograms).
The prototype bomber was powered by four air-cooled, supercharged and fuel-injected 3,347.662-cubic-inch-displacement (54.858 liter) Wright Aeronautical Division Duplex-Cyclone 670C18H1 (R-3350-13) twin-row 18-cylinder radial engines with a compression ratio of 6.85:1. The R-3350-13 was rated at 2,000 horsepower at 2,400 r.p.m., and 2,200 horsepower at 2,800 r.p.m. for takeoff, burning 100-octane gasoline. These engines drove 17-foot-diameter (5.182 meters) three-bladed Hamilton Standard constant-speed propellers through a gear reduction of 0.35:1. The R-3350-13 was 76.26 inches (1.937 meters) long, 55.78 inches (1.417 meters) in diameter, and weighed 2,668 pounds (1,210 kilograms). Wright built 50 of these engines.
The XB-29 had a maximum speed of 368 miles per hour (592 kilometers per hour) and cruised at 255 miles per hour (410 kilometers per hour). Its service ceiling was 32,100 feet (9,784 meters).
The airplane was designed to carry 20,000 pounds (9,072 kilograms) of bombs. Though the prototypes were unarmed, the production B-29s were defended by 10 Browning AN-M2 .50-caliber machine guns in four remotely-operated power turrets, with 2 more .50-caliber machine guns and a single AN-M2 20mm autocannon in the tail.
The B-29 Superfortress was the most technologically advanced—and complex—aircraft of the War. It required the manufacturing capabilities of the entire nation to produce. Over 1,400,000 engineering man-hours had been required to design the prototypes.
The B-29 was manufactured by Boeing at Seattle and Renton, Washington, and at Wichita, Kansas; by the Glenn L. Martin Company at Omaha, Nebraska; and by Bell Aircraft Corporation, Marietta, Georgia. There were three XB-29 prototypes, 14 YB-29 pre-production test aircraft, 2,513 B-29, 1,119 B-29A, and 311 B-29B Superfortress aircraft. The bomber served during World War II and the Korean War and continued in active U.S. service until 1960.
The first prototype, 41-002, was scrapped in 1948.
9 August 1945: Three days after an atomic bomb had been used against the Japanese industrial city of Hiroshima, a second attack was made on Nagasaki. Major Charles W. Sweeney,¹ in command of the Martin-Omaha B-29-35-MO Superfortress 44-27297, named Bockscar, departed Tinian Island in the Marshal Group at 3:47 a.m., and flew to Iwo Jima where it was to rendezvous with two other B-29s, The Great Artiste and The Big Stink, the instrumentation and photographic aircraft for this mission.
Like its sistership, Enola Gay, 44-27297 was a specially modified “Silverplate” B-29. The Silverplate B-29s differed from the standard production bombers in many ways. They were approximately 7,200 pounds (3,266 kilograms) lighter. The bomber carried no armor. Additional fuel tanks were installed in the rear bomb bay. The bomb bay doors were operated by quick-acting pneumatic systems. The bomb release mechanism in the forward bomb bay was replaced by a single-point release as was used in special British Lancaster bombers. A weaponeer’s control station was added to the cockpit to monitor the special bomb systems.
Bockscar had four air-cooled, supercharged, 3,347.662-cubic-inch-displacement (54.858 liter) Wright Aeronautical Division R-3350-41 (Cyclone 18 787C18BA3) two-row 18-cylinder radial engines with direct fuel injection. The R-3350-41 had a compression ratio of 6.85:1 and required 100/130 aviation gasoline. It was rated at 2,000 horsepower at 2,400 r.p.m. at Sea Level, and 2,200 horsepower at 2,800 r.p.m, for take-off. The engines drove four-bladed Curtiss Electric reversible-pitch propellers with a diameter of 16 feet, 8 inches (5.080 meters), through a 0.35:1 gear reduction. The R-3350-41 was 6 feet, 2.26 inches (1.937 meters) long, 4 feet, 7.78 inches (1.417 meters) in diameter and weighed 2,725 pounds (1,236 kilograms).
With the exception of the tail gunner’s position, all defensive armament—four powered remotely operated gun turrets with ten .50-caliber machine guns—were deleted. Their remote sighting positions were also removed. Enola Gay carried 1,000 rounds of ammunition for each of the two remaining Browning AN-M2 .50-caliber machine guns in the tail.
With these changes, the Silverplate B-29s could fly higher and faster than a standard B-29, and the fuel-injected R-3350-41 engines were more reliable. Bockscar had a cruising speed of 220 miles per hour (354 kilometers per hour) and a maximum speed of 365 miles per hour (587 kilometers per hour). Its service ceiling was 31,850 feet (9,708 meters) and its combat radius was 2,900 miles (4,667 kilometers).
44-27297, Victor 7, was assigned to aircraft commander Captain Frederick C. Bock and his crew. Major Sweeney and his crew ordinarily flew The Great Artiste. Sweeney’s B-29 had been the the instrumentation aircraft for the Hiroshima mission and there was not time to remove that equipment and re-install it aboard Bock’s bomber, so the crews switched airplanes. For operational security, Bockscar‘s normal identification was changed from the number 7 on the fuselage to 77. The 509th’s tail code of a circle surrounding a forward-pointing arrow was changed to another unit’s “Triangle N” identification.
All of these last minute changes resulted in confusion in contemporary reports as to which B-29 had actually dropped Fat Man on Nagasaki.
In Bockscar‘s forward bomb bay was a 10,213 pound (4,632 kilograms) bomb called Fat Man. This was a completely different and much more complex weapon than the Little Boy (Mark I) atomic bomb dropped by Colonel Paul Tibbet’s Enola Gay on 6 August. The bomb was 12 feet, 8⅜ inches ¹ (3.261 meters) long, 5 feet, ¼ inch ² (1.530 meters) in diameter,
Designated Mark III, the egg-shaped weapon contained a 9.17 centimeter (3.61 inches), 6.15 kilogram (13.6 pound) sphere of Plutonium Pu 239, with a 2.1 centimeter (0.83 inch) hollow cavity at its center. A beryllium neutron initiator was in this cavity. The plutonium sphere was surrounded by a 22.86 centimeter (9.0 inch) diameter uranium tamper with a mass of 108 kilograms (238 pounds). This nuclear assembly was contained in a boron/acrylic shell and surrounded by about 2,390 kilograms (5,269 pounds) of high-explosive, consisting of Composition B and Baratol. The explosives were formed in “lenses” that would direct the force inward in a very precise manner. The purpose was to compress—or implode— the Plutonium to a much greater density, resulting in a “critical mass.”
In the conduct of this mission, Major Sweeney made a number of serious errors that nearly caused the mission to fail, and might very well have led to the loss of the bomber and its crew.
Prior to takeoff, the B-29’s crew chief informed Sweeney that a fuel transfer pump was inoperative which made it impossible to transfer 625 gallons (2,366 liters) of fuel from one fuel tank. This meant that nearly 9% of the total fuel load of 7,250 gallons (27,444 liters) was unusable. Chuck Sweeney decided to go anyway.
Next, though under direct orders from the 509th Composite Group commander, Colonel Paul Tibbets, to wait at the rendezvous no more than 15 minutes, when The Big Stink failed to arrive on schedule, Sweeney elected to stay 30 minutes beyond that.
Meanwhile, the two weather reconnaissance B-29s, Enola Gay and Laggin’ Dragon, were over Kokura, the primary target, and the secondary, Nagasaki. Weather over both cities were within the mission parameters.
During the 45 minutes that Sweeney waited at the rendezvous, weather over Kokura had deteriorated. By the time Bockscar arrived overhead, clouds covered the city. The bomber made three attempts to bomb the city over a 50-minute period, but the bombardier was not able to see the target.
Now an hour and twenty minutes behind schedule, Sweeney diverted to the secondary target, Nagasaki. Because of the delays and the unusable fuel as a result of the failed fuel pump, Sweeney reduced engine power to try to conserve fuel during the twenty minute flight to the alternate target. But weather there had also deteriorated.
Sweeney decided that they should bomb through the clouds using radar, but at the last minute, the bombardier was able to see the aim point. The Fat Man was dropped from 30,000 feet (9,144 meters) at 11:01 a.m. After falling for 43 seconds, the atomic bomb detonated at an altitude of 1,950 feet (594 meters). It missed the intended target point by nearly 1.5 miles (2.4 kilometers) and exploded over the Urakami Valley, halfway between the Mitsubishi Steel and Arms Works and the Mitsubishi-Urakami Ordnance Works.
The estimated force of the explosion was 21 kilotons—equivalent to the explosive force of 21,000 tons of TNT (19,050 metric tons)—nearly 20% greater than the Hiroshima bomb. The surrounding hills contained the explosion, protecting a large part of the city. Still, approximately 60% of Nagasaki was destroyed and 70,000 people were killed. By December 1945, at least 80,000 of the city’s 250,000 residents had died.
Now critically low on fuel and unable to reach the emergency B-29 recovery field on Iwo Jima, Sweeney headed for the airfields of Okinawa. When Bockscar touched down on the runway, one engine quit due to fuel starvation. As they turned off the runway, a second engine ran out of fuel. Charles Sweeney had cut it very, very close.
Five days after the bombing of Nagasaki, the Emperor of Japan—recognizing that his country now faced total destruction—agreed to surrender. World War II was over.
In 1946, Bockscar was placed in storage at Davis-Monthan Army Air Field, Tucson, Arizona. On 26 September 1961, the B-29 was flown to the National Museum of the United States Air Force, Wright-Patterson Air Force Base, Dayton, Ohio, where it remains in the museum’s collection of historic aircraft.
¹ The other members of the crew of Bockscar were Captain Charles Donald Albury, co-pilot; Second Lieutenant Frederick John Olivi, co-pilot; Captain James Frederick Van Pelt, Jr., navigator; Captain Kermit King Beahan, bombardier; Master Sergeant John Donald Kuharek, flight engineer; Staff Sergeant Raymond C. Gallagher, assistant flight engineer; Staff Sergeant Edward Kenneth Buckley, radar operator; Sergeant Abe M. Spitzer, radio operator; Sergeant Albert Travis Dehart, tail gunner; Commander Frederick Lincoln (“Dick”) Ashworth, U.S. Navy, weaponeer; Lieutenant Philip M. Barnes, U.S. Navy, assistant weaponeer; First Lieutenant Jacob Beser, radar countermeasures. (Lieutenant Beser also flew aboard Enola Gay, 6 August 1945.)
8 July 1941: Three Royal Air Force Boeing Fortress Mk.I heavy bombers departed from their base at RAF Watton to attack Wilhelmshaven, Germany. This was a daylight bombing mission, with the airplanes flying at 30,000 feet (9,144 meters). One bomber diverted to a secondary target because of engine trouble, while the remaining two Fortresses continued to the primary target.
At the very high altitudes flown, the defensive heavy machine guns that gave the airplane its name froze due to the low temperatures and could not be fired. (In standard atmospheric conditions, the temperature at 30,000 feet would be -45 °C., or -49 °F.)
All three aircraft returned safely to their base. The mission was completely ineffective, however.
This was the very first use of the Boeing B-17 Flying Fortress in combat.
The Boeing Model 299H, designated B-17C, was the second production variant ordered by the U.S. Army Air Corps. 38 were built by Boeing for the U.S. Army Air Corps, but 20 were transferred to Great Britain’s Royal Air Force, designated Fortress Mk.I. (Boeing Model 299T.) They were initially assigned to No. 90 Squadron, Bomber Command. (A 1941 book, War Wings: Fighting Airplanes of the American and British Air Forces, by David C. Cooke, Robert M. McBride & Company, New York, refers to the B-17C in British service as the “Seattle,” which is in keeping with the R.A.F.’s system of naming bombers after cities.)
Of the 20 Fortress Mk.I bombers, 8 were lost in combat or in accidents.
The Boeing B-17C/Fortress Mk.I was 67 feet, 10-9/16 inches (20.690 meters long with a wingspan of 103 feet, 9⅜ inches (31.633 meters) and the overall height was 15 feet, 4½ inches (4.686 meters). The B-17C had an empty weight of 30,900 pounds (14,016 kilograms). The maximum design gross weight was 47,500 pounds (21,546 kilograms).
The B-17C was powered by four air-cooled, supercharged, 1,823.129-cubic-inch-displacement (29.876 liters) Wright Cyclone G666A (R-1820-65)¹ nine-cylinder radial engines with a compression ratio of 6.70:1. The engines were equipped with remote General Electric turbochargers capable of 24,000 r.p.m. The R-1820-65 was rated at 1,000 horsepower at 2,300 r.p.m. at Sea Level, and 1,200 horsepower at 2,500 r.p.m. for takeoff. The engine could produce 1,380 horsepower at War Emergency Power. 100-octane aviation gasoline was required. The Cyclones turned three-bladed, constant-speed, Hamilton-Standard Hydromatic propellers with a diameter of 11 feet, 7 inches (3.835 meters) though a 0.5625:1 gear reduction. The R-1820-65 engine is 3 feet, 11.59 inches (1.209 meters) long and 4 feet, 7.12 inches (1.400 meters) in diameter. It weighs 1,315 pounds (596 kilograms).
The B-17C had a maximum speed of 323 miles per hour (520 kilometers per hour) at 25,000 feet (7,620 meters). Its service ceiling was 37,000 feet (11,278 meters) and the maximum range was 3,400 miles (5,472 kilometers).
The Fortress Mk.I could carry 4,800 pounds (2,177 kilograms) of bombs in an internal bomb bay. Defensive armament consisted of one Browning AN-M2 .30-caliber air-cooled machine gun at the nose and four Browning AN-M2 .50-caliber heavy machine guns in dorsal, ventral and waist positions.