Tag Archives: Heavy Bomber

11 December 1945

Bell-Atlanta B-29B-60-BA Superfortress 44-84061, the Pacusan Dreamboat. (U.S. Air Force)
Bell-Atlanta B-29B-60-BA Superfortress 44-84061, the Pacusan Dreamboat. (U.S. Air Force)

11 December 1945: Three days after Lieutenant Colonel Henry E. Warden and Captain Glen W. Edwards set a transcontinental speed record flying a prototype Douglas XB-42 from Long Beach, California, to Washington, D.C., in 5 hours, 17 minutes, Colonel Clarence S. Irvine and the crew of the B-29 Pacusan Dreamboat also set a record, flying from Burbank, California to overhead Floyd Bennett Field, New York, in 5 hours, 27 minutes, 8 seconds. The average speed for the 2,464-mile flight was 450.38 miles per hour (724.82 kilometers per hour).

Lieutenant General Clarence S. Irvine, U.S. Air Force

Irvine was Deputy Chief of Staff, Pacific Air Command, 1944–1947. He flew the Pacusan Dreamboat on several record-setting flights, including Guam to Washington, D.C., and Honolulu, Hawaii to Cairo, Egypt. He rose to the rank of lieutenant general in the United States Air Force, and served as Deputy Chief of Staff for Materiel.

Pacusan Dreamboat was a Bell Aircraft Corporation B-29B-60-BA Superfortress, built at Marietta, Georgia. The B-29B was a lightweight variant of the B-29, intended for operation at lower altitudes. It did not have the four power gun turrets and 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. Pacusan Dreamboat was further lightened. The tail guns were removed and the tail reshaped.

The B-29B was equipped with four air-cooled, fuel-injected Wright R-3350-CA-2 Duplex Cyclone two-row 18 cylinder radial engines and specially-designed propellers. The engine nacelles were modified for improved cooling.

The Superfortress had been lightened to an empty weight of 66,000 pounds (29,937 kilograms). A standard B-29B weighed 69,000 pounds (31,298 kilograms) empty and 137,000 pounds (62,142 kilograms) fully loaded. Additional fuel tanks installed on the Dreamboat were able to carry 10,000 gallons (37,854 liters) of gasoline.

Colonel Clarence S. Irvine (standing, left) with the crew of Pacusan Dreamboat: W.J.Benett, G.F.Broughton, Dock West, W.S. O’Hara, F.S. O’Leary, K.L. Royer, F.J.Shannon, J.A. Shinnault, G.R. Stanley. (FAI)
Colonel Clarence S. Irvine (standing, left) with the crew of Pacusan Dreamboat: W.J. Benett, G.F. Broughton, Dock West, W.S. O’Hara, F.S. O’Leary, K.L. Royer, F.J. Shannon, J.A. Shinnault, G.R. Stanley. (FAI)

© 2015, Bryan R. Swopes

22 November 1933

Kalinen K-7
К-7 на аэродроме (“K-7 at the airport”), right front quarter view. (Уголок неба)

22 November 1933:

The K-7 Disaster

     On Wednesday, November 22, the Russian aircraft K-7, claimed to be the largest landplane in the world, crashed near Kharkhoff, 420 miles south-west of Moscow. Fourteen lives were lost. It is reported that M.K.A. Kalinin, the designer and director of the Kharkhoff aeroplane works, and Snegeriff, one of the best-known pilots in Russia, are among the dead. It seems that sabotage is suspected by the authorities, for the O.G.P.U. (Soviet secret police) is represented on the commission of experts investigating the disaster. Twenty trial flights had been successfully made before the crash.

     The design and construction of the K-7 took five years. She had a span of 208 ft., weighed about 20 tons and accommodated 120 passengers. She was considered a big stride forward in the approach to the “all-wing” aircraft, and most of the accommodation and equipment was in the wing. A few days before the accident the existence of the K-7 was revealed to the general public by “Pravda.” It was declared that the aircraft represented a “victory of the utmost political importance,” as she was constructed entirely of Soviet steel from the mills at Duiepropetrovsk. Hitherto Russia had [imported] materials for her aircraft.

—The Aircraft Engineer, Supplement to FLIGHT, 30 November 1933, at Page 1201.

The K-7 was designed by Konstantin Alekseevich Kalinin and built over a two-year period at the Kharkov State Aircraft Manufacturing Company factory at Kharkov, Ukraine. It was intended as either a heavy bomber in military service or as a civil transport. The K-7 was the largest airplane built up to that time.

К-7 в полете (“K-7 flight”) (Уголок неба)
К-7 в полете (“K-7 flight”) (Уголок неба)
Константин Алексеевич Калинин

The K-7 was an effort to perfect a “wing only” aircraft. The tail surfaces were supported by tail booms. It was operated by a crew of 11 and could carry up to 120 passengers in compartments inside the wings. The K-7 was 28.00 meters (91 feet, 10.4 inches) long with a wingspan of 53.00 meters (173 feet, 10.6 inches). The extremely large wing had an area of 254.00 meters².

As originally built the airplane was powered by six 2,896.1-cubic-inch-displacement (47.459 liter) liquid-cooled, supercharged, Mikulin AM-34 single overhead cam (SOHC) 60° V-12 engines mounted in nacelles on the leading edge of the wing. The engines were rated at 750 horsepower, each, and drove two-bladed propellers. When it was determined that power was insufficient, a seventh and then an eighth engine were added to the trailing edge in pusher configuration.

The K-7 had an empty weight of 21,000 kilograms and maximum weight of 40,000 kilograms. It’s cruise speed was 204 kilometers per hour (127 miles per hour) and the maximum speed was 234 kilometers per hour (145 miles per hour). The service ceiling was 5,500 meters (18,045 feet) and the range was 1,000 kilometers (621 miles).

In military configuration, the K-7 would be armed with 20 mm cannon and 7.62 mm machineguns. A bomb load of up to 16,000 kilograms (35,274 pounds) would be carried.

Cамолет К-7

The Kalinin K-7 made only 7 test flights before it crashed. 15 of the 20 persons aboard were killed. Kalinin was not among the dead, as had been report by Flight in the article above. One of the two tail booms failed. Some suggested that sabotage was involved. A government commission determined that the structure of the tailbooms was sufficiently strong, but that oscillations induced by aerodynamic flutter led to the failure.

During World War I, Konstantin Kalinin was awarded the Order of Sv.Stanislav. He had been given the Order of the Red Banner of Labor in 1935. However, during the Stalin purges, on 23 October 1938, he was executed as an enemy of the state.

Kalinen K-7
К-7 на аэродроме (“K-7 at the airport”), left front quarter view with engines running. (Уголок неба)

© 2018, Bryan R. Swopes

9 October 1943

In this iconic World War II photograph, a Douglas-built B-17F-50-DL Flying Fortress, 42-3352, “Virgin’s Delight,” of the 410th Bomb Squadron, 94th Bombardment Group (Heavy), 8th Air Force, is over the Focke-Wulf Fw 190 fighter factory, Marienburg, East Prussia, 9 October 1943. The aircraft commander was Lieutenant R.E. Le Pore. (U.S. Air Force)

VIII Bomber Command Mission Number 113 was an attack by nearly 100 American heavy bombers on the Focke-Wulf Flugzeugbau AG aircraft factory at Marienburg, East Prussia (Malbork, Poland), where the Luftwaffe‘s Fw 190 fighter was being built. Early in the war, German fighter production had been dispersed and it was thought that Marienburg was beyond the range of Allied bombers.

The Fw 190 was the most effective of Germany’s fighters. More than 20,000 were built in 16 variants.

A captured Focke-Wulf Fw 190 in flight. (U.S. Air Force)
A captured Focke-Wulf Fw 190 G-3 fighter, DN+FP, W.Nr. 160016, in flight. (U.S. Air Force)
Focke-Wulf Fw 190 G-3 DN+FP, W.Nr. 160016, in flight near Wright Field, Ohio, May 1946. (U.S. Air Force)
Focke-Wulf Fw 190 G-3 DN+FP, W.Nr. 160016, from above and behind. (U.S. Air Force)

100 B-17 Flying Fortress bombers were assigned to the target and 96 of these reached the plant. Between 1253 hours and 1302 hours, the B-17s arrived over the target in five waves at 11,000 to 13,000 feet (3,353 to 3,963 meters). They dropped 217.9 tons (197.7 metric tons) of bombs with a very high degree of accuracy.

During the mission, two B-17s were lost with 13 more damaged. Three airmen were wounded and 21 listed as Missing in Action. The bomber crews claimed 9 Luftwaffe aircraft destroyed and 2 probably destroyed in air-to-air combat. Target assessment estimated that 15 Focke-Wulf Fw 190 fighters were destroyed on the ground.

This strike photo was taken from B-17 42-30353 ("Ten Knights in a Bar Room") of the 95th Bombardment Group (Heavy). (U.S. Air Force)
This strike photo was taken from Boeing B-17F-100-BO Flying Fortress 42-30353 (“Ten Knights in a Bar Room”) of the 95th Bombardment Group (Heavy). (U.S. Air Force)

Casualties among the factory work force were high. Of 669 workers, 114 were killed and 76 injured.

Air Chief Marshal Sir Charles Portal, KCB, DSO, MC, Royal Air Force, described the Marienburg attack as the “. . . most perfect example in history of the accurate distribution of bombs over a target.”

Damage assessment photograph
Reconnaissance photograph taken by a de Havilland DH.98 Mosquito PR flown by Squadron Leader R.A. Lenton and Pilot Officer Heney of No. 540 Squadron, R.A.F., 10 October 1943, showing results of the previous day’s attack. (Royal Air Force)
The target area as it appears today. (Google Maps)
"Instrument workers line up aerial cameras at Benson, Oxfordshire, before installing them in a De Havilland Mosquito PR Mark IX: (left to right) two Type F.24 (14-inch lens) vertical cameras, one F.24 (14-inch lens) oblique camera, two Type F.52 (36-inch lens) 'split pair' vertical cameras." (Imperial War Museum CH-18399)
“Instrument workers line up aerial cameras at Benson, Oxfordshire, before installing them in a De Havilland Mosquito PR Mark IX: (left to right) two Type F.24 (14-inch lens) vertical cameras, one F.24 (14-inch lens) oblique camera, two Type F.52 (36-inch lens) ‘split pair’ vertical cameras.” (Imperial War Museum CH-18399)

© 2017, Bryan R. Swopes

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, Carswell AFB, June 1948. (U.S. Air Force Historical Research Agency)

The XB-36 was 162 feet, ½ inch (49.390 meters) long with a wing span of 230 feet (70.104 meters), nearly 90 feet longer than that of the B-29 Superfortress that it would replace. Its height was 46 feet, 9-7/8 inches (14.272 meters) to the tip of the vertical fin. The wings’ leading edges were swept aft 15° 5′ 39″, and the trailing edges, 3°. They had 2° dihedral. The wings’ angle of incidence was 3° and they incorporated 2° of negative twist. The total wing area was 4,772 square feet (443.33 square meters). The prototype’s empty weight was 131,240 pounds (59,530 kilograms), and it had a maximum gross weight of 274,929 pounds (124,706 kilograms).

Convair XB-36 three-view illustration with dimensions. (U.S. Air Force)

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 Curtiss 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 estimated maximum speed was 347 miles per hour (558 kilometers per hour) at 35,000 feet (10,668 meters) and the cruising speed, 216 miles per hour (348 kilometers per hour). The service ceiling was predicted at 36,080 feet (10,997 meters) with all six engines running. It had an estimated range of 9,430 miles (15,176 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)

The bomber was designed to carry a maximum bomb load of 72,000 pounds (32,659 kilograms): as many as 132 500-pound bombs; 72 1,000 pound; 44 1,600 pound; 28 2,000-pound; or 12 4,000-pounders. Defensive armament was planned as two 37mm cannon in each of the forward upper and lower turrets, with 100 rounds of ammunition per gun; four .50-caliber machine guns in the rear upper and lower turrets with 1,000 rounds per gun; and one 37 mm cannon and two .50-caliber machine guns in the tail. The tail cannon would have 300 rounds, and the machine guns, 1,000 rounds per gun.

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 prototype, 42-13570, in flight. (U.S. Air Force)

© 2023, Bryan R. Swopes

28 July 1935

Boeing Model 299, NX13372, photographed during its first flight, 28 July 1935. (The Boeing Company)
Boeing Model 299 X13372, photographed during its first flight, 28 July 1935. (The Boeing Company)
Boeing test pilot Les Tower. (Boeing)
Boeing’s Chief Test Pilot Leslie R. Tower.

28 July 1935, At Boeing Field, Seattle, Chief Test Pilot Leslie Ralph (“Les”) Tower and Louis Waite took off on the maiden flight of the Boeing Model 299, X13372,¹ a prototype four-engine long range heavy bomber. For approximately one-and-a-half hours, Tower flew back and forth between Tacoma and Fort Lewis. When he landed, he said, “It handles just like a little ship—a little bigger, of course.”

The Boeing Model 299 was a four-engine bomber operated by a crew of eight. It  was designed to meet a U.S. Army Air Corps proposal for a multi-engine bomber that could carry a 2,000 pound (907 kilogram) bomb load a distance of 2,000 miles (3,219 kilometers) at a speed greater than 200 miles per hour (322 kilometers per hour). Design of the prototype began in June 1934 and construction was started 16 August 1934. The Air Corps designated it B-299, and later, XB-17. It did not carry a military serial number, being marked with civil experimental registration X13372.

The Boeing Model 299 with Mount Rainier. (U.S. Air Force)
The Boeing Model 299 with Mount Rainier. (U.S. Air Force)

The Model 299 was 68 feet, 9 inches (20.955 meters) long with a wingspan of 103 feet, 9–3/8 inches (31.633 meters) and height of 14 feet, 11–5/16 inches (4.554 meters). Its empty weight was 21,657 pounds (9,823 kilograms). The maximum gross weight was 38,053 pounds (17,261 kilograms).

The prototype was powered by four air-cooled, supercharged, 1,690.537-cubic-inch-displacement (27.703 liter) Pratt & Whitney Hornet S1E-G nine-cylinder radial engines with a compression ratio of 6.5:1. The S1E-G was rated at 750 horsepower at 2,250 r.p.m., and 875 horsepower at 2,300 r.p.m. for takeoff, using 87-octane gasoline. They turned 11 foot, 6 inch (3.505 meters) diameter, three-bladed, Hamilton Standard Hydromatic constant-speed propellers through a 3:2 gear reduction. The S1E-G was 4 feet, 1.38 inches (1.254 meters) long, 4 feet, 6.44 inches (1.383 meters) in diameter and weighed 1,064 pounds (483 kilograms)

Boeing Model 299. (U.S.  Air Force)

In flight testing, the Model 299 had a cruise speed of 204 miles per hour (328 kilometers per hour) and a maximum speed of 236 miles per hour (380 kilometers per hour) at 10,000 feet (3,048 meters). The service ceiling was 24,620 feet (7,504.2 meters). Its maximum range was 3,101 miles (4,991 kilometers). Carrying a 2,573 pounds (1,167 kilograms) load of bombs, the range was 2,040 miles (3,283 kilometers).

Boeing 299 NX13372, all engines running.
Boeing 299 X13372, all engines running.

The XB-17 could carry eight 500 pound (226.8 kilogram) bombs in an internal bomb bay. Defensive armament consisted of five air-cooled Browning .30-caliber machine guns.

Nose turret of the Boeing Model 299, photographed 24 July 1935. (U.S. Air Force)
Nose turret of the Boeing Model 299, photographed 24 July 1935. (The Boeing Company)

X13372 was destroyed when it crashed on takeoff at Wright Field, Dayton, Ohio, 30 October 1935. An Army Air Corps pilot making his first familiarization flight neglected to remove the control locks. This incident led directly to the creation of the ”check list” which is used by all aircraft crew members.

Waist gun position of the Boeing 299. (U.S. Air force)
Waist gun position of the Boeing 299. (The Boeing Company)

Designated XB-17 by the Army Air Corps, this airplane and the YB-17 pre-production models that followed would undergo several years of testing and improvement before entering production as the B-17 Flying Fortress, a legendary airplane of World War II. By the end of the war 12,731 B-17s had been built by Boeing, Douglas and Lockheed Vega.

Boeing Model 299 NX13372, designated XB-17, at Wright Field, Ohio, 1935. (U.S. Air Force)
Boeing Model 299 X13372, designated XB-17, at Wright Field, Ohio, 1935. (U.S. Air Force)

Leslie Ralph Tower was born at Sisseton, South Dakota, 21 January 1903. He was the first of three children of Ralph R. Tower, a farmer who would later serve as a state senator for Montana, and Mayme Amanda Johnson Tower, a Swedish immigrant.

Les Tower attended high school at Polson, Montana, graduating in 1922. He then attended the University of Washington, where he studied engineering. He was a member of the Radio Club.

Tower enlisted in the United States Army as an aviation cadet, training at Brooks and Kelly airfields in Texas. He then served with the 2nd Bombardment Squadron at Langley Field, Virginia.

In 1925 Tower started working for Boeing as a draftsman, but soon began test flying new airplanes, which included the B-9 bomber and the Model 247 commercial airliner. He also demonstrated and delivered Boeing airplanes around the world.

On 20 August 1935, Tower and Louis Wait flew the Model 299 from Seattle to Dayton, approximately 2,100 miles, in 9 hours, 3 minutes, averaging 233 miles per hour (375 kilometers per hour).

Les Tower was aboard the XB-17 as an observer during the 30 October flight. He saw that the control locks had not been released and tried to reach them, but was unable. In the fire that followed the crash, Tower suffered severe burns to his face, right arm and both legs.

Leslie Ralph Tower died of his injuries 19 November 1935 at Miami Valley Hospital in Dayton. His remains were transported by train, escorted by Army airplanes, and were buried at Lakeview Cemetery, Polson, Montana.

¹ At that time, experimental and restricted category aircraft were prohibited from displaying the letter “N” at the beginning of their registration mark.

© 2020, Bryan R. Swopes