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.
27 June 1941: The experimental Douglas XB-19 long range heavy bomber took off on its first flight from Clover Field, Santa Monica, California. The four-engine airplane, which had originally been designated XBLR-2, serial number 38-471, was under the command of Major Stanley Milward Ulmstead, U.S. Army Air Corps, with 7 additional crewmembers. (Ulmstead had previously made the first flight of the Boeing XB-15.)
Major Ulmstead flew the XB-19 from Santa Monica to March Field in Riverside County. The duration of the flight was 55 minutes.
The Douglas XB-19 was a gigantic airplane for its time. The airplane was 132 feet, 1-7/8 inches (40.281225 meters) long with a wingspan of 212 feet, 0 inches (64.618 meters) and overall height of 41 feet, 4½ inches (12.611 meters). Its empty weight was 86,000 pounds (39,009 kilograms), and the gross weight, 140,000 pounds (63,503 kilograms). The maximum takeoff weight was 162,000 pounds (73,482 kilograms).
The wings had a chord of 33 feet, 0 inches (10.058 meters) at the root, and a maximum thickness of 8 feet (2.44 meters). The total area was 4,285 square feet (398.09 square meters). Their angle of incidence was 6°, and they had 6° dihedral. The wings were swept aft 10° 13′ at 25% chord.
The XB-19 was powered by four air-cooled, supercharged, direct-fuel-injected 3,347.662-cubic-inch-displacement (54.858 liter) Wright Aeronautical Division R3350-5 Duplex-Cyclone (GR3350A77) twin-row 18-cylinder radial engines. These had a compression ratio of 6.85:1 and required 100-octane gasoline. They had a normal power rating of 1,620 horsepower at 2,300 r.p.m., and a maximum 2,000 horsepower at 2,400 r.p.m. The R3350-5 was 4 feet, 7.12 inches (1.400 meters) in diameter, 5 feet, 11.5 inches (1.816 meters) long, and weighed 2,450 pounds (1,111 kilograms). The engines turned three-bladed propellers with a diameter of 18 feet, 2 inches (5.537 meters) through a 16:7 gear reduction.
The XB-19 had a cruise speed of 135 miles per hour (217 kilometers per hour) and a maximum speed of 224 miles per hour (360 kilometers per hour) at 15,700 feet (4,785 meters). The service ceiling was 39,000 feet (11,887 meters) and the maximum range was 7,750 miles (12,472 kilometers).
Defensive armament consisted of two 37 mm cannon, five .50-caliber machine guns, and six .30-caliber machine guns.
The XB-19 was converted to a transport and re-engined with experimental liquid-cooled, turbosupercharged Allison V-3420-11 24-cylinder “double-vee” engines. It was redesignated XB-19A. The airplane was scrapped at Davis-Monthan Air Force Base, Tucson, Arizona, in July 1949.
16–17 May 1943: Nineteen modified Avro Lancaster B.III Special long-range heavy bombers of No. 617 Squadron, Royal Air Force, carried out Operation Chastise, a low-level night attack against four hydroelectric dams in the Ruhr Valley.
The purpose of the attack was to disrupt German steel production. It was estimated that 8 tons of water were required to produce 1 ton of steel. Breaching the dams would reduce the available water and hydroelectric power, disrupt transportation of materials on the rivers, and flood iron ore and coal mines and power plants. If the dams were destroyed, it was believed that the effects would be the same as attacks against 26 categories of industrial targets further down the Ruhr Valley.
Led by 24-year-old Wing Commander Guy Penrose Gibson, D.S.O. and Bar, D.F.C. and Bar, a veteran of 172 combat missions, the aircrews of No. 617 Squadron dropped a spinning cylindrical bomb, code-named “Upkeep,” from a height of just 60 feet (18.3 meters) over the reservoirs behind the dams, while flying at precisely 240 miles per hour (386.2 kilometers per hour).
The 9,250-pound (4,195.8 kilogram) Vickers Type 464 bomb was designed to skip along the surface and to strike the dam, and then sink to the bottom. There, a pressure detonator exploded the 6,600 pound (2,994 kilogram) Torpex charge directly against the wall with the water pressure directing the energy through the wall.
Nineteen Lancasters took off from RAF Scampton in Lincolnshire, England, beginning at 9:28 p.m. on the 16th, and flew across the North Sea at only 100 feet (30.5 meters) to avoid being detected by enemy radar. The bombers succeeded in destroying the Möhne and Eder dams and damaging the Sorpe. A fourth dam, the Ennepe, was attacked but not damaged. The last surviving bomber returned to base at 6:15 a.m. on the 17th.
Of the nineteen Lancasters launched, two were damaged and turned back before reaching the targets. Six were shot down and two more collided with power lines during the low-level night flight. Of 133 airmen participating in the attack, 53 were killed.
For his planning, training and execution of the raid, Wing Commander Gibson was awarded the Victoria Cross by King George VI. An additional 33 survivors were also decorated. 617 Squadron became known as “The Dambusters.” A book, The Dam Busters, was written about the raid by Paul Brickhill, who also wrote The Great Escape. A 1955 movie starred Richard Todd, O.B.E., as Wing Commander Gibson. There have been reports that a new movie is planned.
The Avro Lancaster B.III Special was a four-engine long range heavy bomber modified to carry the Type 464 bomb. It was operated by a crew of seven: Pilot, flight engineer, navigator, radio operator, bomb aimer, nose gunner and tail gunner. The “Lanc” was 69 feet, 6 inches (21.184 meters) long with a wingspan of 102 feet, 0 inches (31.090 meters) and overall height of 20 feet, 4 inches (6.198 meters), in 3-point position. The Lancaster’s wings had a total area of 1,300.0 square feet (120.8 square meters). Their angle of incidence was 4° and the outer wing panels had 7° dihedral. The span of the horizontal stabilizer was 33 feet, 0 inches (10.058 meters). The modified bomber had an empty weight of 35,240 pounds (15,984.6 kilograms and a maximum takeoff weight (MTOW) of 60,000 pounds (27,215.5 kilograms).
The Lancaster B.III Special was powered by the Packard Motor Car Company’s license-built version of the Rolls-Royce Merlin 24, the Packard V-1650-1 Merlin 224. These were liquid-cooled, supercharged, 1,648.96-cubic-inch-displacement (27.022-liter) single overhead cam (SOHC) 60° V-12 engines with four valves per cylinder and a compression ratio of 6.0:1. The Merlin 224 used a two-speed, single-stage supercharger. 100/130-octane aviation gasoline was required. The engine had a Normal Power rating of 1,080 horsepower at 2,650 r.p.m. and 9,500 feet (2,896 meters); Military Power, 1,240 horsepower at 3,000 r.p.m. at 11,000 feet (3,353 meters); and 1,300 horsepower at 3,000 horsepower with 54.3 inches of manifold pressure (1.84 Bar) for Takeoff. The Merlins drove three-bladed de Havilland Hydromatic quick-feathering, constant-speed propellers which had a diameter of 13 feet (3.962 meters). The propeller gear reduction ratio was 0.477:1. The V-1650-1 was 6 feet, 7.7 inches (2.024 meters) long, 2 feet, 6.0 inches (0.762 meters) wide and 3 feet, 6.6 inches (1.082 meters) high. It weighed 1,512 pounds (685.8 kilograms).
These engines gave the Lancaster a cruising speed of 200 miles per hour (321.9 kilometers per hour) and maximum speed of 272 miles per hour (437.7 kilometers per hour). The service ceiling was 24,700 feet (7,528.6 meters) and maximum range was 2,530 miles (4,071.6 kilometers).
Defensive armament for a standard Lancaster consisted of eight air-cooled Browning .303-caliber Mark II machine guns in three power turrets, nose, dorsal and tail. The Lancasters assigned to Operation Chastise had the dorsal turret deleted to reduce weight and aerodynamic drag. The gunner normally operating that turret was moved to the front turret, relieving the bomb aimer to deal with the operation of the specialized mission equipment.
7,377 Avro Lancasters were built. Only two remain in airworthy condition.
Highly Recommended: The Dam Busters, by Paul Brickhill. Evans Brothers, London, 1951
15 May 1942: The first Ford-built B-24 Liberator long range heavy bomber came off the assembly line at the Willow Run Airplane Plant, just 160 days after the United States entered World War II. 6,971 B-24s more would follow, along with assembly kits for another 1,893, before production came to an end, 28 June 1945.
30 April 1959: Convair B-36J-1-CF Peacemaker, serial number 52-2220, landed at Wright-Patterson Air Force Base, Dayton, Ohio, completing the very last flight ever made by one of the giant Cold War-era bombers. It is on the collection of the National Museum of the United States Air Force.
Convair B-36J 52-2220 was among the last group of 33 B-36 bombers built. It was operated by an aircraft commander/pilot, co-pilot, two navigators, bombardier, two flight engineers, two radio operators, two electronic countermeasures operators and five gunners, a total 16 crewmembers. Frequently a third pilot and other additional personnel were carried.
The bomber 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 171,035 pounds (77,580 kilograms) and combat weight is 266,100 pounds (120,700 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 (71.49 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 had a cruise speed of 203 miles per hour (327 kilometers per hour) and a maximum speed of 411 miles per hour (661 kilometers per hour) at 36,400 feet (11,905 meters) . The service ceiling was 39,900 feet (12,162 meters) and its range was 6,800 miles (10,944 kilometers) with a 10,000 pound (4,536 kilogram) bomb load. The maximum range was 10,000 miles (16,093 kilometers).
Designed during World War II, nuclear weapons were unknown to the Consolidated-Vultee engineers. The bomber was built to carry up to 86,000 pounds (39,009 kilograms) of conventional bombs in two bomb bays. It could carry the 43,600 pound (19,776.6 kilogram) T-12 Cloudmaker, a conventional explosive earth-penetrating bomb, or several Mk.15 thermonuclear bombs. By combining the bomb bays, one Mk.17 25-megaton thermonuclear bomb could be carried.
For defense, the B-36J had six retractable defensive gun turrets and gun turrets in the nose and tail. All 16 guns were remotely operated. Each position mounted two M24A1 20 mm autocannons. 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.