Tag Archives: Curtiss P-40 Warhawk

14 October 1938

The Curtiss-Wright XP-40 prototype, 38-10, on its first flight, 14 October 1938. Test pilot Ed Elliot is in the cockpit. (San Diego Air and Space Museum Archives) 16_008532

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 Reese Berlin, had taken the tenth production P-36A Hawk, Air Corps serial number 38-10, and had its air-cooled radial engine replaced with the Harold Caminez-designed, liquid-cooled, supercharged, 1,710.597-cubic-inch-displacement (28.032 liter) Allison Engineering Co. V-1710-C13 (V-1710-19).

Donovan Reese Berlin. (Niagara Aerospace Museum)

The V-1710-19 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 inches (1.035 meters) high and 2 feet, 4.94 inches (0.735 meters) wide. It weighed 1,320 pounds (599 kilograms).

Curtiss-Wright XP-40 38-10 (SDASM 16_008531)

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.

XP-40 16_008533
Curtiss-Wright XP-40 prototype. (SDASM 16_008534)
The Curtiss XP-40 prototype at Langley Field in the original configuration. (NASA)
The Curtiss-Wright XP-40 in the original configuration at Langley Field. (NASA)
Everett Edward Elliot (1907–1981).

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-Wright XP-40 prototype in a wind tunnel at Langley Field, 24 April 1939. (NASA)
Curtiss XP-40 in the NACA Full Scale Wind Tunnel at Langley Field, Virginia, April 1939. (NASA)
Curtiss-Wright XP-40 in the NACA Full Scale Wind Tunnel at Langley Field, Virginia, 24 April 1939. (NASA)

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.

A Curtiss-Wright P-40B Warhawk, 79th Pursuit Squadron, 20th Pursuit Group, Hamilton Field, California, 1940. (U.S. Air Force)

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.

A Curtiss-Wright Hawk 81-A3 (Tomahawk IIb) of the American Volunteer Group, Kunming, China, 1942. (U.S. Air Force)

© 2018, Bryan R. Swopes

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4 April 1940

Chief test Pilot H. Lloyd Child (left, wearing goggles and flight suit) with a P-40 Warhawk. (LIFE Magazine)
Chief Test Pilot H. Lloyd Child (left, wearing goggles and flight suit) and Herbert O. Fisher, Chief Production Test Pilot, look at a Curtiss-Wright P-40 Warhawk. (Dmitri Kessel, LIFE Magazine)

4 April 1940: Curtiss-Wright’s Chief Test Pilot H. Lloyd Child flew the first production P-40 Warhawk, c/n13033, Air Corps serial number 39-156, on its first flight at Buffalo, New York.

Curtiss Model 81, P-40 Tomahawk. (San Diego Air and Space Museum Archive)
Curtiss-Wright Model 81, P-40 Warhawk 39-156. (San Diego Air and Space Museum Archive)

The Curtiss-Wright Corporation Hawk 81 (P-40 Warhawk) was a single-seat, single-engine pursuit. It was a low-wing monoplane of all-metal construction and used flush riveting to reduce aerodynamic drag. It had an enclosed cockpit and retractable landing gear (including the tail wheel). Extensive wind tunnel testing at the NACA Langley laboratories refined the airplane’s design, significantly increasing the top speed.

Curtiss P-40 Warhawk 39-156. (U.S. Air Force)
Curtiss-Wright P-40 Warhawk 39-156. (U.S. Air Force)

The new fighter was 31 feet, 8-9/16 inches (9.666 meters) long with a wingspan of 37 feet, 3½ inches (11.366 meters) and overall height of 9 feet, 7 inches (2.921 meters). The P-40’s empty weight was 5,376 pounds (2,438.5 kilograms) and gross weight was 6,787 pounds (3,078.5 kilograms).

Curtiss P-40 Warhawk 39-156. (U.S. Air Force)
Curtiss-Wright P-40 Warhawk 39-156. (U.S. Air Force)

The P-40 was powered by a liquid-cooled, supercharged, 1,710.597-cubic-inch-displacement (28.032 liter) Allison Engineering Co. V-1710-C15 (V-1710-33), a single overhead cam (SOHC) 60° V-12 engine with a compression ratio of 6.65:1. The V-1710-33 had a continuous power rating of 930 horsepower at 2,600 r.p.m. at 12,800 feet (3,901 meters), and 1,040 horsepower at 2,800 r.p.m. for takeoff, burning 100-octane gasoline. It turned a three-bladed Curtiss Electric constant-speed propeller through a 2:1 gear reduction. The V-1710-33 was 8 feet, 2.54 inches (2.503 meters) long, 3 feet, 5.88 inches (1.064 meters) high, and 2 feet, 5.29 inches (0.744 meters) wide. It weighed 1,340 pounds (607.8 kilograms).

A 1939 Allison Engine Company V-1710-33 liquid-cooled, supercharged SOHC 60° V-12 aircraft engine at the Smithsonian Institution National Air and Space Museum. This engine weighs 1,340 pounds (607.8 kilograms) and produced 1,040 horsepower at 2,800 r.p.m. During World War II, this engine cost $19,000. (NASM)
Allison Engineering Co. V-1710-33 V-12 aircraft engine at the Smithsonian Institution National Air and Space Museum Steven F. Udvar-Hazy Center. (NASM)

The cruising speed of the P-40 was 272 miles per hour (438 kilometers per hour) and the maximum speed was 357 miles per hour (575 kilometers per hour) at 15,000 feet (4,572 meters). The Warhawk had a service ceiling of 30,600 feet (9,327 meters) and the absolute ceiling was 31,600 feet (9,632 meters). The range was 950 miles (1,529 kilometers) at 250 miles per hour (402 kilometers per hour).

The fighter (at the time, the Air Corps designated this type as a “pursuit”) was armed with two air-cooled Browning AN-M2.50-caliber machine guns on the engine cowl, synchronized to fire through the propeller arc, with 380 rounds of ammunition per gun. Provisions were included for one Browning M2 .30-caliber aircraft machine gun in each wing, with 500 rounds per gun.

Captain Charles W. Stark, Jr., 35th Pursuit Squadron, climbing from the cocpit of Curtis P-40 Warhawk 39-188, at Langley, Field, Virginia, 1941.
Captain Charles W. Stark, Jr., 35th Pursuit Squadron, 8th Pursuit Group, climbing from the cockpit of Curtis-Wright P-40 Warhawk 39-188, at Langley, Field, Virginia, 1941. (Rudy Arnold Collection/NASM))

On 26 April 1939, the U.S. Army Air Corps ordered 524 P-40 Warhawks, the largest single aircraft order up to that time. Only 200 of these aircraft were produced in the P-40 configuration. The Army deferred its order to allow Curtiss-Wright to produce Hawk 81A fighters for France. France fell before any could be delivered and 140 of these were taken over by Britain’s Royal Air Force as the Tomahawk Mk.I. Another 16 P-40s were delivered to the Soviet Air Force, having been purchased with gold.

The 8th Pursuit Group at Langley Field, Virginia, was the first Army Air Corps unit to be equipped with the P-40.

On 30 May 1942, P-40 39-156 was being flown by 2nd Lieutenant Leon Marcel Zele, 55th Fighter Squadron, 20th Fighter Group, based at Morris Field, North Carolina. At approximately 11:00 a.m., the P-40 crashed near Iron Station, North Carolina. Lieutenant Zele was killed when the airplane exploded.

A Curtiss P-40 Warhawk of the 33rd Pursuit Squadron, 8th Pursuit Group, Langley Field, Virginia, 1941. (U.S. Air Force)
A Curtiss-Wright P-40 Warhawk of the 33rd Pursuit Squadron, 8th Pursuit Group, Langley Field, Virginia, 1941. (Alfred T. Palmer)

Henry Lloyd Child was born at Philadelphia, Pennsylvania, 25 May 1904, the second of two children of Edward Taggart Child, a consulting engineer in shipbuilding, and Lillian Rushmore Cornell Child. He was baptised at the Church of the  Good Shepherd, Rosemont, Pennsylvania, 22 December 1913. Child graduated from Flushing High School in Flushing, New York, then attended the Haverford School in Philadelphia.

“Skipper” Child majored in mechanical engineering at the University of Pennsylvania where he was a member of the Hexagon Senior Engineering Society and the Phi Sigma Kappa (ΦΣΚ) and Sigma Tau (ΣΤ) fraternities. He was a member of the varsity and all-state soccer team (left halfback), and also played football and tennis. Child graduated with a bachelor of science degree, 15 June 1926.

After graduation from college, Child went to work for the Curtiss-Wright Corporation as an engineer.

Child joined the United States Navy, 23 November 1927. He was trained as a pilot at Naval Air Station Hampton Roads, Norfolk, Virginia, and was commissioned as an Ensign. He was promoted to lieutenant (junior grade), 7 November 1932, and to lieutenant, 11 November 1935.

While maintaining his commission in the Navy, Child returned to Curtiss-Wright as a test pilot. He made the first flight of the P-36 Hawk.

He became famous as the “World’s Fastest Human” when he put a Hawk 75A demonstrator into a vertical dive from 22,000 feet (6,706 meters), over Buffalo Airport, 24 January 1939. It was believed at the time that he had reached a speed in excess of 575 miles per hour (925 kilometers per hour). A contemporary news report said that the needle of the recording instrument had gone off the edge of the graph paper, and that the actual speed may have been faster than 600 miles per hour (966 kilometers per hour).

H. Lloyd Child worked for Lockheed from 1958 to 1968, when he retired. He died at Palmdale, California 5 August 1970 at the age of 66 years.

H. Lloyd Child, Curtiss-Wright Corporation chief test pilot. (Test and Research Pilots, Flight Test Engineers)

© 2017, Bryan R. Swopes

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