Tag Archives: Allison Division of General Motors

26 January 1946

Colonel William H. Council, U.S. Army Air Corps, in teh cockpit of his record-setting Lockheed P-80A-1-LO Shooting Star. (San Diego Air and Space Museum)
Colonel William H. Councill, U.S. Army Air Forces, in the cockpit of his record-setting Lockheed P-80A-1-LO Shooting Star. (San Diego Air and Space Museum Archive)

26 January 1946: Colonel William Haldane Councill, U.S. Army Air Forces, a test pilot at the Flight Test Division, Wright Field, Ohio, made a record-breaking flight from Daugherty Field (Long Beach Airport), California, to overhead LaGuardia Airport, New York, in 4 hours, 13 minutes, 26 seconds. He was piloting a Lockheed P-80A-1-LO Shooting Star, serial number 44-85123. This flight set a new transcontinental speed record for the 2,457 miles (3,954 kilometers), averaging 584.82 miles per hour (941.18 kilometers per hour).

Colonel Councill was accompanied by two other P-80s flown by Captain John S. Babel and Captain Martin I. Smith. This was the longest non-stop flight by a jet aircraft up to that time.

Colonel Councill’s P-80A had been modified with the installation of a 100-gallon (379 liters) fuel tank in the nose. Along with 300-gallon (1,135 liters) wing tip tanks, the Shooting Star’s maximum fuel load had been increased to 1,165 gallons (4,410 liters).¹

The P-80s flown by Captains Babel and Smith also had the nose fuel tank installed, but carried 150-gallon wing tip tanks. They had to stop at Topeka, Kansas to refuel. Ground crews met them with four fuel trucks, and they were airborne in 4 minutes and 6 minutes, respectively.

Colonel William H. Councill, U.S. Air force, waves from the cockpit of his record-setting Lockheed P-80A-1-LO Shooting Star, 44-85123. (AP Wirephoto, Oklahoma Historical Society)
Colonel William H. Councill, U.S. Air Force, waves from the cockpit of his record-setting Lockheed P-80A-1-LO Shooting Star, 44-85123. (AP Wirephoto, Photograph 2012.201.B0243.0237, Oklahoma Historical Society)

William Haldane Councill was born 5 October 1911 at Bellevue, Pennsylvania. He was the second of four children of William Mansfield Councill, a manager for a fireproofing company, and Bertha Etta Wing Councill.

William H. Councill. (The Thistle of 1933)

Bill Councill studied at the Carnegie Institute of Technology, Pittsburgh, Pennsylvania. He was a member of the Reserve Officers Training Corps (R.O.T.C.), and the Delta Upsilon (ΔΥ) fraternity. He was also a member of the Scabbard and Blade, and co-chairman of the Military Ball. Councill graduated in 1933 with a Bachelor of Science in Mechanical Engineering degree (B.S.M.E.).

William H. Councill was commissioned as a second lieutenant, Engineer Reserve, 1 June 1933. He was appointed a flying cadet and trained as a pilot, 1 October 1933 to 14 October 1935. He then received a commission as a second lieutenant, Air Reserve.

Lieutenant Councill married Miss Lillie Louise Slay at Wahiawa Heights, Honolulu, Territory of Hawaii, 18 April 1936. They would have one daughter, Frances, born in 1943.

On 1 October 1938, Councill’s reserve commission was converted to second lieutenant, Air Corps, United States Army. Councill was promoted to first lieutenant, 1 October 1941.

During this time William Councill held a parallel commission in the Army of the United States. He was promoted to first lieutenant, A.U.S., 9 September 1940, and captain, A.U.S., 1 February 1942. On 1 March 1942, he was promoted to the rank of major, A.U.S. (A.C.), and to lieutenant colonel, 19 December 1942. On 3 July 1945, Councill advanced to the rank of colonel, A.U.S.

Colonel Councill was rated as a command pilot. During World War II, he flew 130 combat missions with the 13th Air Force in the southwest Pacific area. He was awarded the Distinguished Flying Cross and the Air Medal with four oak leaf clusters.

At 10:54 a.m., 5 April 1954, Colonel Councill took off from Farmingdale, New York, in a Lockheed T-33A Shooting Star, enroute to Langley Field, Virginia. He never arrived. An extensive search was unsuccessful. It was presumed that Councill went down in the Atlantic Ocean.

According to his commanding officer, Major General Earl W. Barnes,

“. . . He was a most capable, dependable and responsible officer who was concientiously devoted to his tasks. His opinions on military matters were highly regarded by his superior officers. His pleasant personality, genial manner, and dry wit endeared him to the hearts of the many friends he had won during approximately twenty-one years of service in the United States Air Force. He was greatly beloved by those with whom he associated. . . I feel that our Country and the Air Force have lost an irreplaceable asset and a great leader.”

Wing Family Annals, Wing Family of America, Inc., Des Moines, Iowa. Vol. 54, No. 1, at Pages 7 and 8

Clarence L. “Kelly” Johnson with a scale model of a Lockheed P-80A-1-LO Shooting Star. Johnson’s “Skunk Works” also designed the F-104 Starfighter, U-2, A-12 Oxcart and SR-71A Blackbird. (Lockheed Martin Aeronautical Company)

The Lockheed P-80-1-LO was the United States’ first operational jet fighter. It was a single-seat, single engine airplane, designed by a team of engineers led by Clarence L. (“Kelly”) Johnson. The prototype XP-80A, 44-83020, nicknamed Lulu-Belle, was first flown by test pilot Tony LeVier at Muroc Army Air Field (now known as Edwards Air Force Base) 8 January 1944.

The P-80A was 34 feet, 6 inches (10.516 meters) long with a wingspan of 38 feet, 10.5 inches (11.849 meters) and an overall height of 11 feet, 4 inches (3.454 meters). It weighed 7,920 pounds empty (3,592.5 kilograms) and had a maximum takeoff weight of 14,000 pounds (6,350.3 kilograms).

Early production P-80As were powered by either an Allison J33-A-9 or a General Electric J33-GE-11 turbojet engine. The J33 was a licensed version of the Rolls-Royce Derwent. It was a single-shaft turbojet with a 1-stage centrifugal compressor section and a 1-stage axial-flow turbine. The -9 and -11 engines were rated at 3,825 pounds of thrust (17.014 kilonewtons). The were 8 feet, 6.9 inches (2.614 meters) long, 4 feet, 2.5 inches (1.283 meters) in diameter and weighed 1,775 pounds (805 kilograms).

Colonel Council's record-setting P-80A-1-LO in squadron markings. (U.S. Air Force)
Colonel Councill’s record-setting P-80A-1-LO 44-85123, in squadron markings at the National Air Races, Cleveland, Ohio, September 1946. (Unattributed)

The P-80A had a maximum speed of 558 miles per hour (898 kilometers per hour) at Sea Level and 492 miles per hour (801 kilometers per hour) at 40,000 feet (12,192 meters). The service ceiling was 45,000 feet (13,716 meters).

Several hundred of the early production P-80 Shooting stars had all of their surface seams filled, and the airplanes were primed and painted. Although this process added 60 pounds (27.2 kilograms) to the empty weight, the decrease in drag allowed a 10 mile per hour (16 kilometers per hour) increase in top speed. The painted surface was difficult to maintain in the field and the process was discontinued.

The P-80A Shooting Star was armed with six Browning AN-M2 .50-caliber (12.7×99 NATO) machine guns mounted in the nose.

Lieutenant Howard A. Johnson, USAAF, with Lockheed P-80A-1-LO Shooting Star 44-85123. (FAI)

On 3 June 1946, Lockheed P-80A-1-LO Shooting Star 44-85123, flown by Lieutenant Henry A. Johnson, set a Fédération Aéronautique Internationale (FAI) World Record for Speed Over a Closed Circuit of 1,000 Kilometers with an average speed of 745.08 kilometers per hour (462.97 miles per hour).²

On 2 September 1946, Major Gustav Lindquist won the Thompson Trophy Race, J Division, at the National Air Races, Cleveland, Ohio, 1946, with the same airplane, averaging 515.853 miles per hour (830.185 kilometers per hour) over a 180-kilometer (111.85-mile) course.

Today, 44-85123 is in the collection of the Air Force Flight Test Museum, Edwards Air Force Base. It is currently undergoing restoration.

Lockheed test pilots Anthony W. ("Tony") LeVier and David L. Ferguson stand in front of P-80A 44-85123 and an F-117A Nighthawk at the Lockheed Skunk Works, Palmdale, California, 17 June 1993. (Denny Lombard, Lockheed Martin)
Lockheed test pilots Anthony W. (“Tony”) LeVier and David L. Ferguson stand in front of P-80A Shooting Star 44-85123 and an F-117A Nighthawk at the Lockheed Skunk Works, Palmdale, California, 17 June 1993. (Denny Lombard, Lockheed Martin)

¹ Thanks to Jeffrey P. Rhodes of Lockheed Martin for additional information on Colonel Councill’s Lockheed P-80A Shooting Star.

² FAI Record File Number 10973

© 2018, Bryan R. Swopes

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10 January 1966

The prototype Bell Model 206A JetRanger, serial number 1, civil registration N8560F, hovering out of ground effect. (Bell Helicopter Company)
The prototype Bell Model 206A JetRanger, serial number 1, civil registration N8560F, hovering out of ground effect. (Bell Helicopter Company)

10 January 1966: The prototype Bell Model 206A JetRanger serial number 1, N8560F, made its first flight at at the Bell Helicopter Company plant at Hurst, Texas. This aircraft would be in production for almost 45 years. The final JetRanger to be built, Bell 206B-3 serial number 4690, was delivered in December 2010 and production came to an end.

During early production of the Model 206A, cabin sections were built by Beechcraft and Agusta then shipped to Bell at Fort Worth. (The vertical seam just to the rear of the fuel cap distinguished the two.) Oil pressure and temperature gauges for the engine and transmission, the loadmeter and fuel quantity indicator were provided by Cessna.

The  Bell JetRanger is a 5-place, single-engine light civil helicopter based on the Bell Helicopter’s unsuccessful OH-4 entrant for the U.S. Army’s Light Observation Helicopter (LOH, or “loach”) contract. It is flown by a single pilot in the right front seat. Dual flight controls can be installed for a second pilot. The helicopter was certified for VFR flight, but could be modified for instrument flight.

The industrial design firm of Charles Wilfred Butler “. . . was responsible for the complete redesign of the Bell OH4A prototype army helicopter (1961) into the Bell Jet Ranger (1965). He and his designers restyled the machine inside and out in the manner of automotive design, creating in the process one of the world’s most successful and beautiful helicopters.”Encyclopedia Britannica.

The JetRanger is 38 feet, 9.5 inches (11.824 meters) long, overall. On standard skid landing gear the overall height is 9 feet, 4 inches (2.845 meters). The Bell 206A has an empty weight of approximately 1,700 pounds (771 kilograms), depending on installed equipment. The maximum gross weight is 3,200 pounds (1,451.5 kilograms). With an external load suspended from the cargo hook, the maximum gross weight is increased to 3,350 pounds (1,519.5 kilograms).

The two-bladed main rotor is semi-rigid and under-slung, a common feature of Bell’s main rotor design. It has a diameter of 33 feet, 4.0 inches (10.160 meters) and turns counter-clockwise (seen from above) at 394 r.p.m. (100% NR). (The advancing blade is on the helicopter’s right side.) The rotor blade has a chord of 1 foot, 1.0 inches (0.330 meter) and 10° negative twist. The airfoil is symmetrical. The cyclic and collective pitch controls are hydraulically-boosted.

The first Bell 206B JetRanger (Bell Helicopter Co.)
The first Bell 206A JetRanger, N8560F. (Bell Helicopter Co.)

The two-bladed tail rotor assembly is also semi-rigid and is positioned on the left side of the tail boom in a pusher configuration. It turns at 2,550 r.p.m., clockwise, as seen from the helicopter’s left. (The advancing blade is below the axis of rotation.) The tail rotor diameter is 5 feet, 6.0 inches (1.676 meters).

The turboshaft engine is mounted above the roof of the fuselage, to the rear of the main transmission. Output shafts lead forward to the transmission and aft to the tail rotor 90° gear box. The transmission and rotor mast are mounted tilting slightly forward and to the left. This assists in the helicopter’s lift off to a hover, helps to offset its translating tendency, and keeps the passenger cabin in a near-level attitude during cruise flight.

A vertical fin is attached at the aft end of the tail boom. The fin is offset 4° to the right to unload the tail rotor in cruise flight. Fixed horizontal stabilizers with an inverted asymmetric airfoil are attached to the tail boom. In cruise flight, these provide a downward force that keeps the passenger cabin in a near-level attitude.

The 206A was powered by an Allison 250-C18 turboshaft engine (T63-A-700) which produced a maximum of 317 shaft horsepower at 104% N1, 53,164 r.pm. The improved Model 206B JetRanger and 206B-2 JetRanger II used a 370 horsepower 250–C20 engine, and the Model 206B-3 JetRanger III had 250-C20B, -C20J or -C20R engines installed, rated at 420 shaft horsepower at 105% N1, (53,519 r.p.m.). Many 206As were upgraded to 206Bs and they are sometimes referred to as a “206A/B.” The Allison 250-C20B has a 7-stage compressor section with 6-stage axial-flow stages, and 1 centrifugal-flow stage. The 4-stage axial-flow turbine has a 2-stage gas producer (N1) and 2-stage power turbine (N2). These were very light weight engines, ranging from just 141 to 173 pounds (64.0 to 78.5 kilograms).

The helicopter’s main transmission is limited to a maximum input of 317 shaft horsepower (100% Torque, 5-minute limit). The engine’s accessory gear unit reduces the output shaft speed to 6,016 r.p.m. N2, which is further reduced by the transmission’s planetary gears, and the tail rotor 90° gear box.

The JetRanger has a maximum speed, VNE, of 150 miles per hour (241 kilometers per hour) up to 3,000 feet (914 meters). Its best rate of climb, VY, is at 60 miles per hour (97 kilometers per hour) and best speed in autorotation (minimum rate of descent and maximum distance) is at 80 miles per hour (129 kilometers per hour), resulting in a glide ratio of about 4:1. The service ceiling is 13,500 feet (4,145 meters) with the helicopter’s gross weight above 3,000 pounds (1,361 kilograms), and 20,000 feet (6,096 meters) when below 3,000 pounds. The helicopter has a maximum range of 430 miles (692 kilometers).

After being used as a factory demonstrator and development aircraft, N8560F was retired from flight status and used as a maintenance ground training device at Bell’s training school at Hurst.

Note: The Model 206A-1 was adopted by the U.S. Army as the OH-58A Kiowa. Though very similar in appearance to the Model 206A and 206B, the OH-58A differs significantly. Few of the parts are interchangeable between the types.

Three view drawing of the Bell Model 206A/B JetRanger with dimensions. (Bell Helicopter TEXTRON)
Three view drawing of the Bell Model 206A/B JetRanger with dimensions. (Bell Helicopter TEXTRON)

© 2018, Bryan R. Swopes

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5 January 1956

Piasecki YH-16A-PH Transporter 50-1270 hovers in ground effect.
Piasecki YH-16A-PH Transporter 50-1270 hovers in ground effect. (Piasecki Aircraft Corporation)

5 January 1956: The prototype Piasecki Helicopter Company YH-16A-PH Transporter twin-turboshaft, tandem-rotor helicopter, serial number 50-1270, was returning to Philadelphia from a test flight, when, at approximately 3:55 p.m., the aft rotor desynchronized, collided with the forward rotor and the aircraft broke up in flight. It crashed at the Mattson Farm on Oldman’s Creek Road, near Swedesboro, New Jersey, and was completely destroyed.

Test pilots Harold W. Peterson and George Callahan were killed.

It was determined that a bearing associated with an internal coaxial shaft supporting test data equipment had seized, causing the rotor shaft to fail.

Harold W. Peterson (left) and George Callahan, with the prototype Piasecki YH-16A Turbo Transporter, 50-1270. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)
Harold W. Peterson (left) and George Callahan, with the prototype Piasecki YH-16A Turbo Transporter, 50-1270. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)

At the time, the YH-16 was the largest helicopter in the world. The United States Air Force intended it as a very-long-range rescue helicopter, while the U.S. Army expected it to serve as a heavy lift cargo and troop transport.

YH-16 50-1269 was powered by two 2,181.2-cubic-inch-displacement (35.74 liter) air-cooled, supercharged Pratt & Whitney Twin Wasp E2 (R-2180-11) two-row, fourteen-cylinder radial engines with a Normal Power Rating of 1,300 horsepower at 2,600 r.p.m. at 8,000 feet ( meters), and 1,650 horsepower at 2,600 rp.m., for Takeoff.

The second YH-16A, 50-1270, was modified while under construction and was powered by two Allison Division YT38-A-10 turboshaft engines which produced 1,800 shaft horsepower, each. This made the YH-16A the world’s first twin-engine turbine-powered helicopter.

The Piasecki YH-16A Transporter was the world's largest helicopter in 1956. (Piasecki Aircraft Corporation)
The Piasecki YH-16A Transporter was the world’s largest helicopter in 1956. (Piasecki Aircraft Corporation)

The YH-16A had a fuselage length of 78 feet (23.774 meters), and both main rotors were 82 feet (24.994 meters) in diameter. With rotors turning, the overall length was 134 feet ( meters). Their operating speed was 125 r.p.m. Overall height of the helicopter was 25 feet (7.62 meters). The helicopter’s empty weight was 22,506 pounds (10,209 kilograms) and the gross weight was 33,577 pounds (15,230 kilograms).

The cruise speed of the YH-16A was 146 miles per hour (235 kilometers per hour). In July 1955, Peterson and Callahan had flown 50-1270 to an unofficial record speed of 165.8 miles per hour (266.83 kilometers per hour). The service ceiling was 19,100 feet (5,822 meters) and the maximum range for a rescue mission was planned at 1,432 miles (2,305 kilometers).

After the accident, the H-16 project was cancelled.

Prototype Piasecki YH-16A Transporter 50-1270, hovering in ground effect at Philadelphia Airport, 1955. (Piasecki Aircraft Corporation)
Prototype Piasecki YH-16A Transporter 50-1270, hovering in ground effect at Philadelphia Airport, 1955. (Piasecki Aircraft Corporation)

© 2017, Bryan R. Swopes

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7 December 1941

Lieutenants Ken Taylor and George Welch, U.S. Army Air Corps. (U.S. Air Force)
Lieutenants Kenneth Marlar Taylor and George Schwartz Welch, Air Corps, United States Army. (U.S. Air Force)

On the morning of December 7, 1941, very few American fighter pilots were able to get airborne to fight the Japanese attackers. Ken Taylor and George Schwartz were two of them.

Distinguished Service Cross
Distinguished Service Cross

Second Lieutenants Kenneth Marlar Taylor and George S. Welch took two Curtiss-Wright P-40B Warhawk fighters from a remote airfield at Haleiwa, on the northwestern side of the island of Oahu, and against overwhelming odds, each shot down four enemy airplanes: Welch shot down three Aichi D3A Type 99 “Val” dive bombers and one Mitsubishi A6M2 Type 0 (“Zero”) fighter. Taylor also shot down four Japanese airplanes.

Although both officers were nominated for the Medal of Honor by General Henry H. (“Hap”) Arnold, they were awarded the Distinguished Service Cross.

During the War, Welch flew the Bell P-39 Airacobra and Lockheed P-38 Lightning on 348 combat missions. He had 16 confirmed aerial victories over Japanese airplanes and rose to the rank of Major.

Suffering from malaria, George Welch was out of combat and recuperating in Australia. When North American Aviation approached General Arnold to recommend a highly experienced fighter pilot as a test pilot for the P-51H Mustang, Arnold suggested Welch and authorized his resignation from the Air Corps.

Aichi D3A Type 99 dive bomber, “Val”. (San Diego Air and Space Museum Archives)

George Welch tested the P-51H, XP-86 Sabre and YF-100A Super Sabre for North American Aviation. Reportedly, while demonstrating the F-86 Sabre’s capabilities to Air Force pilots during the Korean War, he shot down as many as six MiG 15s.

George Welch was killed while testing a F-100A Super Sabre, 12 October 1954.

A Mitsubishi A6M2 Type 0 Model 21, A1-108, flown by PO2c Sakae Mori, takes of from IJN Akagi, an aircraft carrier of the Imperial Japanese Navy, 7 December 1941. (U.S. Navy)

Ken Taylor scored two more victories at Guadalcanal before wounds received in an air raid sent him back to the United States. He remained in the Air Force until he retired in 1971 with the rank of Brigadier General. He died in 2006.

The Curtiss-Wright Corporation Hawk 81B (P-40B 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. Extensive wind tunnel testing at the NACA Langley laboratories refined the airplane’s design, significantly increasing the top speed.

The P-40B Warhawk was 31 feet, 8¾ inches (9.671 meters) long, with a wingspan of 37 feet, 4 inches (11.379 meters). Its empty weight was 5,590 pounds (2,536 kilograms), an 7,326 pounds (3,323 kilograms) gross. The maximum takeoff weight was 7,600 pounds (3,447 kilograms).

The P-40B was powered by a liquid-cooled, supercharged, 1,710.60-cubic-inch-displacement (28.032 liter) Allison Engineering Co. V-1710-C15 (V-1710-33), a single overhead cam (SOHC) 60° V-12 engine, which produced 1,040 horsepower at 2,800 r.p.m., and 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).

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)
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)

Heavier than the initial production P-40, the P-40B was slightly slower, with a maximum speed of 352 miles per hour (567 kilometers per hour). It had a service ceiling of 32,400 feet (9,876 meters) and range of 730 miles (1,175 kilometers).

Armament consisted of two air-cooled Browning AN-M2 .50-caliber machine guns mounted in the cowling and synchronized to fire forward through the propeller arc, with 380 rounds per gun, and four Browning M2 .30-caliber aircraft machine guns, with two in each wing.

Curtiss-Wright produced 13,738 P-40s between 1939 and 1944. 131 of those were P-40B Warhawks.

A flight of six Curtiss P-40B Warhawks of the 44th Pursuit Squadron, 18th Pursuit Group, over the Territory of Hawaii, August 1941. (U.S. Air Force)
A flight of six Curtiss-Wright P-40B Warhawks of the 44th Pursuit Squadron, 18th Pursuit Group, over the island of Oahu, Territory of Hawaii, 9:00 a.m., 1 August 1941. (U.S. Air Force)

© 2016, Bryan R. Swopes

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14 October 1938

The Curtiss-Wright XP-40 prototype on its first flight, 14 October 1938. Test pilot Ed Elliot is in the cockpit. (San Diego Air and Space Museum Archives)
The Curtiss-Wright XP-40 prototype on its first flight, 14 October 1938. Test pilot Ed Elliot is in the cockpit. (San Diego Air and Space Museum Archives)
Everett Edward Elliot (1919–1981). Photograph courtesy of Neil Corbett, Test Pilot and Engineers)
Everett Edward Elliot (Photograph courtesy of Neil Corbett, Test Pilot and Engineers)

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.

Curtiss-Wright XP-40 prototype. (SDASM)
The Curtiss XP-40 prototype at Langley Field in the original configuration. (NASA)
The Curtiss XP-40 in the original configuration at Langley Field. (NASA)

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.

Lt. Benjamin Scovill Kelsey, U.S. Army Air Corps, in  the cockpit of a Curtiss P-36A Hawk at Wright Field, 1938. (U.S. Air Force)

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 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 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 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 Hawk 81-A3 (P-40B Warhawk) of the American Volunteer Group, Kunming, China, 1942. (U.S. Air Force)

© 2017, Bryan R. Swopes

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