15 October 1955: At Edwards Air Force Base, California, Lieutenant Gordon L. (“Gordo”) Gray, Jr., United States Navy, set a Fédération Aéronautique Internationale (FAI) World Record For Speed Over a Closed Circuit of 500 Kilometers when he flew a pre-production Douglas Aircraft Company YA4D-1 Skyhawk light attack bomber, Bureau of Aeronautics serial number (Bu. No.) 137820, to an average speed of 1,118.7 kilometers per hour (695.128 miles per hour).¹
The Douglas A4D-1 Skyhawk is a single-place, single-engine, delta-winged light attack bomber designed for operation from aircraft carriers. It is 39 feet, 4 inches (11.989 meters) long with a wingspan of 27 feet, 6 inches (8.382 meters) and overall height of 15 feet (4.572 meters). Its empty weight is 8,400 pounds (3,810.2 kilograms). It was powered by a Curtiss-Wright J65-W-2, a licensed-production version of the Armstrong Siddeley Sapphire axial flow turbojet engine, which had a 13-stage compressor and 2-stage turbine. It produced 7,200 pounds of thrust (32.03 kilonewtons).
The A4D was in production from 1956 to 1979. 2,960 one- and two-place aircraft were built. The Skyhawk remained in service with the United States Navy until 2003.
14 October 1938: At Buffalo, New York, test pilot Everett Edward Elliot made the first flight in the new Curtiss-Wright Corporation’s Model 75P, a prototype for a single-engine pursuit plane which had been designated XP-40 by the U.S. Army Air Corps.
Curtiss-Wright’s Chief Engineer, Donovan Berlin, had taken the tenth production P-36A Hawk, Air Corps serial number 38-10, and had its air-cooled radial engine replaced with a Harold Caminez-designed, liquid-cooled, supercharged, 1,710.597-cubic-inch-displacement (28.032 liter) Allison Engineering Co. V-1710-C13 (V-1710-19). This was a single overhead cam (SOHC) 60° V-12 engine with four valves per cylinder and a compression ration of 6.65:1. It had a Normal Power rating of 910 horsepower at 2,600 r.p.m. at Sea Level, and 1,060 horsepower at 2,950 r.p.m. for Takeoff. At 10,000 feet (3,048 meters), the V-1710-19 had Maximum Continuous Power rating of 1,000 horsepower at 2,600 r.p.m., and Military Power rating of 1,150 horsepower at 2,950 r.p.m. The engine required 100/130-octane aviation gasoline. It drove a three-bladed Curtiss Electric constant-speed propeller through a 2:1 gear reduction. The V-1710-19 was 8 feet, 1.75 inches (2.483 meters) long, 3 feet, 4.75″ (1.035 meters) high and 2 feet, 4.94 inches (0.735 meters) wide. It weighed 1,320 pounds (599 kilograms).
At 1,829.39-cubic-inches (29.978 liters), the original Pratt & Whitney Twin Wasp S1C1-G (R-1830-17) 14-cylinder radial engine had greater displacement and produced 80 horsepower more for takeoff than the Allison V-12. The long, narrow V-12, though, allowed for a much more streamlined engine cowling for higher speed and greater efficiency.
In the early testing, the XP-40 was much slower than expected, reaching only 315 miles per hour (507 kilometers per hour). (The P-36A Hawk had a maximum speed of 313 miles per hour). Engineers experimented with different placement for the coolant radiator, oil coolers and the engine air intake. The Air Corps project officer, Lieutenant Benjamin Scovill Kelsey, had the prototype sent to the National Advisory Committee for Aeronautics (NACA) Research Center at Langley Field, Virginia, where the full-size airplane was placed inside a wind tunnel.
Over a two-month period, NACA engineers made a number of improvements. The radiator was moved forward under the engine and the oil coolers utilized the same air scoop. The exhaust manifolds were improved as were the landing gear doors.
When they had finished, Lieutenant Kelsey flew the modified XP-40 back to Curtiss. Its speed had been increased to 354 miles per hour (570 kilometers per hour), a 12% improvement.
By December 1939 the airplane had been further improved and was capable of 366 miles per hour (589 kilometers per hour).
The Curtiss Hawk 75P, XP-40 38-10, was 31 feet, 1 inch (9.574 meters) long with a wingspan of 37 feet, 4 inches (11.354 meters) and overall height of 12 feet, 4 inches (3.734 meters). It had an empty weight of 5,417 pounds (2,457.1 kilograms) and maximum gross weight of 6,870 pounds (3,116.2 kilograms).
The prototype had a maximum speed of 342 miles per hour (550 kilometers per hour) at 12,200 feet (3,719 meters) with a gross weight of 6,260 pounds (2,839.5 kilograms). Its range was 460 miles (740 kilometers) flying at 299 miles per hour (481 kilometers per hour) with 100 gallons (378.5 liters) of fuel. With 159 gallons (601.9 liters) and with speed reduced to 200 miles per hour (322 kilometers per hour), the XP-40 had a maximum range of 1,180 miles (1,899 kilometers).
The prototype was armed with two air-cooled Browning AN-M2 .50-caliber machine guns mounted above the engine and synchronized to fire forward through the propeller arc.
The Air Corps placed an initial order for 524 P-40s. This was the largest single order for airplanes by the U.S. military up to that time. The first production model was the P-40 Warhawk, armed with two .50-caliber machine guns. There was only one P-40A variant which was a P-40 modified as a camera aircraft. The definitive pursuit model was the P-40B Warhawk, which retained the two .50-caliber guns of the P-40 and added two Browning M2 .30-caliber machine guns to each of the wings.
The P-40B was best known as the airplane flown by the American Volunteer Group fighting for China against the Japanese. They were called the “Flying Tigers”. Between 1939 and 1945, Curtiss built 13,738 P-40s in many configurations. They flew in combat in every theater of operations during World War II.
5 October 1954: Chief Engineering Test Pilot Tony LeVier made the first flight in the second prototype Lockheed XF-104 Starfighter, 53-7787, at Edwards Air Force Base in the high desert of southern California. This was the armament test aircraft and was equipped with a General Electric T171 Vulcan 20mm Gatling gun. This six-barreled gun was capable of firing at a rate of 6,000 rounds per minute.
The XF-104 was 49 feet, 2 inches (14.986 meters) long with a wingspan of 21 feet, 11 inches (6.680 meters) and overall height of 13 feet, 6 inches (4.115 meters). The prototypes had an empty weight of 11,500 pounds (5,216 kilograms) and maximum takeoff weight of 15,700 pounds (7,121 kilograms).
While the first prototype, 53-7776, was equipped with a Buick J65-B-3 turbojet engine, the second used a Wright Aeronautical Division J65-W-6 with afterburner. Both were improved derivatives of the Armstrong Siddely Sa.6 Sapphire, built under license. The J65 was a single-shaft axial-flow turbojet with a 13-stage compressor and 2-stage turbine. The J65-B-3 was rated at 7,330 pounds of thrust, and the J65-W-6, rated at 7,800 pounds (34.70 kilonewtons), and 10,500 pounds (46.71 kilonewtons) with afterburner.
The XF-104 had a maximum speed of 1,324 miles per hour (2,131 kilometers per hour), a range of 800 miles (1,287 kilometers) and a service ceiling of 50,500 feet (15,392 meters).
The YF-104A pre-production aircraft and subsequent F-104A production aircraft had many improvements over the two XF-104 prototypes. The fuselage was lengthened 5 feet, 6 inches (1.68 meters). The J65 engine was replaced with a more powerful General Electric J79-GE-3 turbojet. There were fixed inlet cones added to control airflow into the engines. A ventral fin was added to improve stability.
53-7787 was lost 19 April 1955 when it suffered explosive decompression at 47,000 feet (14,326 meters) during a test of the T171 Vulcan gun system. The lower escape hatch had come loose due to an inadequate latching mechanism. Lockheed test pilot Herman R. (“Fish”) Salmon was unable to find a suitable landing area and ejected at 250 knots (288 miles per hour/463 kilometers per hour) and 15,000 feet (4,572 meters). The XF-104 crashed 72 miles (117 kilometers) east-northeast of Edwards Air Force Base. Salmon was found two hours later, uninjured, about 2 miles (3.2 kilometers) from the crash site.
14 August 1942: The 27th Fighter Squadron (Twin Engine), 1st Fighter Group, VIII Fighter Command, was ferrying its Lockheed P-38 Lightning fighters across the North Atlantic Ocean from Presque Isle, Maine to England as part of Operation Bolero. Iceland was a mid-Atlantic fuel stop on the Northern Ferry Route.
Just over a week earlier, 6 August 1942, 30 Curtiss P-40C Warhawks of the 33rd Fighter Squadron had been flown off the aircraft carrier USS Wasp (CV-7). Among the 32 Army Air Corps pilots who boarded the carrier with the fighters at Norfolk, Virginia, was Second Lieutenant Joseph D.R. Shaffer, U.S.A.A.C., service number O-427002.
On the morning of 14 August, a Royal Air Force Northrop N-3PB Nomad of No. 330 Squadron (Norwegian) tracked a German Luftwaffe Focke-Wulf Fw 200 C-4 Condor four-engine maritime reconnaissance bomber, marked NT+BY, flying near a convoy south of the island. The bomber then proceeded northward and overflew the peninsula west of Reykjavik.
Lieutenant Shaffer, his squadron now assigned to the 342d Composite Group, Iceland Base Command, one of the units responsible for the air defense of Iceland, located and attacked the Condor with his P-40, damaging one of the bomber’s engines.
At 11:15 a.m., two P-38s of the 27th Squadron, flown by Major John W. Weltman and Second Lieutenant Elza E. Shahan, followed up Shaffer’s attack. Shahan was flying Lockheed P-38F-1-LO Lightning, serial number 41-7540.
The Fw 200 was hit in and around the bomb bay. It exploded and went into the sea approximately 8 miles northwest of Grotta Point. Its crew, F Ofw. Fritz Kühn, Ofw. Phillip Haisch, Ofw. Ottmar Ebner, Uffz. Wolgang Schulze, Ofw. Arthur Wohlleben and Ofw. Albert Winkelmann were all killed.
This was the very first U.S. Army Air Forces air combat victory in the European Theater of Operations during World War II. Lieutenants Shaffer and Shahan both shared credit for the victory. They were awarded the Silver Star for their actions.
6 August 1945: At 0245 hours, a four-engine, long range heavy bomber of the 509th Composite Group, United States Army Air Forces, took off from North Field on the island of Tinian in the Marshall Group, on the most secret combat mission of World War II.
The Martin-Omaha B-29-45-MO Superfortress, 44-86292, under the command of Colonel Paul W. Tibbets, Jr., was carrying Bomb Unit L-11, the first nuclear weapon to be used during war. This was a 9,700-pound (4,400 kilogram) “gun type” fission bomb, the Mark I, code-named Little Boy. It contained 64 kilograms (141.1 pounds) of highly-enriched uranium. The bomb was 120 inches (3.048 meters) long with a diameter of 28 inches (0.711 meter). Although it was a very inefficient weapon, it was considered to be such reliable design that it had not been tested.
On the morning before the mission, Colonel Tibbets had his mother’s name painted on the nose of the airplane: Enola Gay. He had personally selected this bomber, serial number 44-86292, while it was still on the assembly line at the Glenn L. Martin Company plant at Bellevue, Nebraska, 9 May 1945. The B-29 was accepted by the Army Air Corps on 15 May and flown to the 509th’s base at Wendover, Utah, by Captain Robert A. Lewis, a B-29 aircraft commander who would act as Tibbets’ co-pilot on the atomic bombing mission.
The B-29 Superfortress was designed by the Boeing Airplane Company as its Model 345. Produced in three major version, the B-29, B-29A and B-29B, it was built by Boeing at Wichita, Kansas and Redmond, Washington; by the Bell Aircraft Corporation at Marietta, Georgia; and the Glenn L. Martin Company at Fort Crook (now Offutt Air Force Base, Omaha, Nebraska. A total of 3,943 Superfortresses were built.
The B-29 was the most technologically advanced airplane built up to that time, and required an immense effort by American industry to produce.
The B-29 Superfortress was 99 feet, 0 inches (30.175 meters) long with a wingspan of 141 feet, 3 inches (43.053 meters) and an overall height of 27 feet, 9 inches (8.458 meters). The standard B-29 had an empty weight of 74,500 pounds (33,793 kilograms) and gross weight of 120,000 pounds (54.431 kilograms).
The Silverplate B-29s differed from the standard production bombers in many ways. They were approximately 6,000 pounds (2,722 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.
Enola Gay 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 new engines were more reliable. Enola Gay 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).
At 09:15:17 a.m., (mission time, 8:15 a.m., local), Enola Gay was at 31,000 feet (9,450 meters) over the Japanese city of Hiroshima on the island of Honshu, an industrial center with a population of about 340,000 people. The bombardier initiated the automatic release sequence and the the atomic bomb was dropped. It fell for 44.4 seconds and detonated at an altitude of 1,968 feet (600 meters), about 800 feet (244 meters) from the aiming point, the Aioi Bridge over the Ota River.
Ground Zero, the point on the surface directly below the explosion, was the Shima Hospital. The overpressure is estimated to have been 4.5–6.7 tons per square meter. The two-story brick building was completely obliterated. Of the patients, technicians, nurses and doctors inside, nothing remained.
The resulting explosion was approximately equivalent in explosive force to the detonation of 16,000 tons (14,515 metric tons) of TNT (16 “kilotons”). An estimated 70,000 people were killed immediately, and another 70,000 were wounded. As many as 160,000 people may have died as a result of the atomic bombing by the end of 1945. More would follow over the next few years.
An area of the city with a radius of 1 mile (1.6 kilometers) from the point of detonation (“hypocenter”) was totally destroyed, and combined with the fires that followed, 4.7 square miles (12.17 kilometers²) of the city were destroyed. 69% of all buildings in Hiroshima were completely destroyed and another 6% damaged.
As soon as the bomb was released, Colonel Tibbets turned his B-29 away to avoid the blast. It was just over 11 miles (17.7 kilometers) from the detonation point when the shock waves hit, but no damage resulted. The bomber was then flown back to Tinian, landing after an elapsed time of 12 hours, 13 minutes.
Enola Gay was placed in storage at Davis-Monthan Army Air Field, Tucson, Arizona, 26 July 1946, and was transferred to the Smithsonian Institution just over one month later, 30 August 1946. For decades it sat in storage at different locations around the country, but finally a total restoration was performed. Today, the B-29 is on display at the Steven F. Udvar-Hazy Center, National Air and Space Museum.