Tag Archives: Allison Engineering Company

18 December 1941

First Lieutenant Boyd D. Wagner, USAAC. (U.S. Air Force)
First Lieutenant Boyd David Wagner, United States Army Air Corps. (U.S. Air Force)

18 December 1941: First Lieutenant Boyd David (“Buzz”) Wagner, United States Army Air Corps, commanding officer of the 17th Pursuit Squadron (Interceptor) at Nichols Field, Pasay City, Commonwealth of the Philippines, shot down his fifth Japanese airplane, a Mitsubishi A6M2 Type Zero fighter, with his Curtiss-Wright P-40B Warhawk, near Vigan, Luzon. He became the first U.S. Army “ace” of World War II.

On 12 December 1941, “Buzz” Wagner was flying a lone reconnaissance mission over the airfield at Aparri, which had been captured by the invading Japanese. He was attacked by several Zero fighters but he evaded them, then returned and shot down two of them.  As he strafed the airfield he was attacked by more Zeros and shot down two more, bringing his score for the mission to four enemy airplanes shot down.

On 18 December, Lieutenant Wagner lead a flight of four P-40s to attack the enemy-held airfield at Vigan. He and Lieutenant Russell M. Church strafed and bombed the field while two other P-40s covered from overhead. Wagner destroyed nine Japanese aircraft on the ground, but as he passed over the field a Zero took off. Wagner rolled inverted to locate the Zero, then after spotting him, chopped his throttle and allowed the Zero to pass him. This left Wagner in a good position and he shot down his fifth enemy fighter. Lieutenant Church was shot down by ground fire and killed.

Mitsubishi A6M3 Model 22 "Zeke" in the Solomon Islands, 1943. (Imperial Japanese Navy)
A Mitsubishi A6M3 Navy Type 0 Model 22, UI 105, (Allied reporting name “Zeke”, but better known simply as “the Zero”) in the Solomon Islands, May 1943. This fighter is flown by Petty Officer 1st Class Hiroyoshi Nishizawa, 251st Kōkūtai, Imperial Japanese Navy Air Service. (Imperial Japanese Navy)

This fifth shoot down made Buzz Wagner the first U.S. Army Air Corps ace of World War II. He was awarded the Distinguished Service Cross, the Distinguished Flying Cross, and the Purple Heart for injuries sustained in an air battle, 22 December 1941. He was evacuated to Australia in January 1942.

2nd Lieutenant Boyd D. Wagner, Air Corps, United States Army.

Boyd David Wagner was born 26 October 1916 at Emeigh, Pennsylvania. He was the first of two children of Boyd Matthew Wagner, a laborer, and Elizabeth Moody Wagner. After graduating from high school, Wagner enrolled in the University of Pittsburgh, where he majored in aeronautical engineering.

After three years of college, Boyd Wagner enlisted as a flying cadet in the U.S. Army Air Corps, at Pittsburgh, Pennsylvania, 26 June 1937. He was commissioned as a Second Lieutenant, Air Corps Reserve, 16 June 1938. Lieutenant Wagner received advanced flight training and pursuit training, and on 1 October 1938 his commission as a reserve officer was changed to Second Lieutenant, Army Air Corps.

Wagner was promoted to First Lieutenant, Army of the United States, on 9 September 1940. Lieutenant Wagner was assigned to the 24th Pursuit Group in the Philippine Islands, 5 December 1940.

1st Lieutenant Boyd David Wagner, United States Army Air Corps, Philippine Islands, 1 December 1941. (Photograph by Carl Mydans/TIME & LIFE Pictures/Getty Images)
Lt. Col. Boyd D. Wagner

Lieutenant Wagner was promoted to the rank of Captain, A.U.S., 30 January 1942. On 11 April 1942, Captain Wagner was again promoted, bypassing the rank of Major, to Lieutenant Colonel, A.U.S. He was assigned to the 8th Fighter Group in New Guinea. On 30 April 1942, while flying a Bell P-39 Airacobra, Wagner shot down another three enemy airplanes. In September 1942, Colonel Wagner was sent back to the United States to train new fighter pilots.

On 29 November 1942, Colonel Wagner disappeared while on a routine flight from Eglin Field, Florida, to Maxwell Field, Alabama, in a Curtiss-Wright P-40K Warhawk, 42-10271. Six weeks later, the wreck of his fighter was found, approximately 4 miles north of Freeport, Florida. Lieutenant Colonel Boyd David Wagner, United States Army Air Corps, had been killed in the crash. His remains are buried at Grandview Cemetery, Johnstown, Pennsylvania.

Curtiss P-40B Warhawks at Clark Field, Philippine Islands, early December 1941.
Curtiss-Wright P-40B Warhawks of the 17th Pursuit Squadron, Nichols Field, Luzon, Philippine Islands, early December 1941. This squadron was under the command of 1st Lieutenant Buzz Wagner. (U.S. Air Force)

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) and overall height of 10 feet, 7 inches (3.226 meters). Its empty weight was 5,590 pounds (2,536 kilograms), and 7,326 pounds (3,323 kilograms) gross. The maximum takeoff weight was 7,600 pounds (3,447 kilograms).

Curtiss-Wright P-40B or C Warhawk, circa 1942. (Niagara Aerospace Museum)

The P-40B 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, which had a Continuous Power Rating of 930 horsepower at 2,600 r.p.m., from Sea Level to 12,800 feet (3,901 meters), and 1,150 horsepower at 3,000 r.p.m. to 14,300 feet  (4,359 meters) for Take Off and Military Power. The engine drove 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) at 15,000 feet (4,572 meters). It had a service ceiling of 32,400 feet (9,876 meters). Its range was 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 of ammunition per gun, and four Browning AN-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.

These Curtiss P-40B Warhawks of the 44th Pursuit Squadron, 18th Pursuit Group, are the same type aircraft flown by Buzz Wagner. (U.S. Air Force)
These Curtiss P-40B Warhawks of the 44th Pursuit Squadron, 18th Pursuit Group, are the same type aircraft flown by Buzz Wagner in combat over the Philippine Islands. (U.S. Air Force)

© 2018, Bryan R. Swopes

Medal of Honor, Major Richard Ira Bong, United States Army Air Forces

Major Richard Ira Bong, Air Corps, United States Army, Leyte, 12 December 1944. Major Bong is wearing the Medal of Honor. (U.S. Air Force)

17 December 1944: Major Richard Ira Bong, United States Army Air Corps, flying a Lockheed P-38 Lighting over San José on the Island of Mindoro, Commonwealth of the Philippines, shot down an enemy Nakajima Ki-43 Hayabusa (Allied reporting name, “Oscar”).

This was Bong’s 40th confirmed aerial victory and made him the leading American fighter ace of World War II. He is officially credited with 40 aircraft destroyed, 8 probably destroyed and 7 damaged.

Five days earlier, 12 December, during a ceremony at an American airfield on the Island of Leyte, Philippine Islands, General Douglas MacArthur, United States Army, had presented Major Bong the Medal of Honor.

An Associated Press reporter quoted the General:

“Of all military attributes, that one which arouses the greatest admiration is courage. It is the basis of all successful military ventures. our forces possess it to a high degree and various awards are provided to show the public’s appreciation. The Congress of the United States has reserved to itself the honor of decorating those amongst all who stand out as the bravest of the brave. It’s this high and noble category, Bong, that you now enter as I pin upon your tunic the Medal of Honor. Wear it as a symbol of the invincible courage you have displayed so often in mortal combat. My dear boy, may a merciful God continue to protect you is the constant prayer of your commander in chief.”

[On 18 December 1944, Douglas MacArthur was promoted to General of the Army, a five-star rank held by only nine other U.S. military officers. General MacArthur was the son of a Medal of Honor recipient, and had himself been twice nominated for the Medal for his actions during the occupation of Vera Cruz (1914) and the Meuse-Argonne Offensive (1918). He was awarded the Medal of Honor for his defense of the Philippines, 1941–42.]

General Douglas MacArthur talks with Major Richard I. Bong, 12 December 1944. (U.S. Air Force)
General Douglas MacArthur talks with Major Richard I. Bong, Leyte, Philippine Islands, 12 December 1944. (U.S. Air Force)

Richard Bong’s citation reads:

MEDAL OF HONOR

The President of the United States of America, in the name of Congress, takes pleasure in presenting the Medal of Honor to Major (Air Corps) Richard Ira Bong, United States Army Air Forces, for conspicuous gallantry and intrepidity in action above and beyond the call of duty while serving with the 49th Fighter Group, V Fighter Command, Fifth Air Force, in action in the Southwest Pacific area from 10 October to 15 November 1944.

Though assigned to duty as gunnery instructor and neither required nor expected to perform combat duty, Major Bong voluntarily and at his own urgent request engaged in repeated combat missions, including unusually hazardous sorties over Balikpapan, Borneo, and in the Leyte area of the Philippines. His aggressiveness and daring resulted in his shooting down eight enemy airplanes during this period.

General Orders: War Department, General Orders No. 90, December 8, 1944
Action Date: October 10 – November 15, 1944
Service: Army Air Forces
Rank: Major
Regiment: 49th Fighter Group, V Fighter Command
Division: 5th Air Force.

Dick Bong poses with "Marge," his Lockheed P-38J Lightning. A large photograph of his fiancee, Miss Marjorie Vattendahl, is glued to the fighter's nose.
Dick Bong poses with “Marge,” his Lockheed P-38J-15-LO Lightning, 42-103993, Lockheed serial number 2827. A large photograph of his fiancée, Miss Marjorie Ann Vattendahl, is affixed to the fighter’s nose.

Major Bong flew a number of different Lockheed P-38s in combat. He is most associated, though, with P-38J-15-LO 42-103993, which he named Marge after his fiancée, Miss Marjorie Ann Vattendahl, a school teacher from Poplar, Wisconsin.

Richard Bong had flown 146 combat missions. General George C. Kenney, commanding the Far East Air Forces, relieved him from combat and ordered that he return to the United States. He was assigned to test new production P-80 Shooting Stars jet fighters being built at Lockheed Aircraft Corporation’s Burbank, California plant.

On 6 August 1945, the fuel pump of the new P-80 Bong was flying failed just after takeoff. The engine failed from fuel starvation and the airplane crashed into a residential area of North Hollywood, California. Major Richard Ira Bong was killed.

Nakajima Ki-43 Type 1 Army Fighter (AvionsLegendaires.net)

The Nakajima Ki-43 Type 1 Hayabusa was a single-place, single-engine fighter manufactured by Nakajima Hikoki K.K. for the Imperial Japanese Army Air Service. The light weight fighter was very maneuverable and was a deadly opponent. It was identified as “Oscar” by Allied forces. The Ki-43 shot down more Allied airplanes during World War II than any other Japanese fighter.

The Ki-43 was 29.2 feet (8.90 meters) long, with a wingspan of 35.6 feet (10.85 meters) and height of 9 feet (2.74 meters). Its empty weight was 4,170 pounds (1,878 kilograms) and gross weight  was 5,500 pounds (2,495 kilograms).

The Ki-43 Type 1 Army Fighter was powered by an air-cooled, supercharged Nakajima Ha-115 Toku two-row, 14-cylinder radial engine which produced 925 horsepower at 9,350 feet (2,850 meters), 800 horsepower  at 20,000 feet (6,096 meters), and 1,105 horsepower at Sea Level for takeoff. The engine drove a three-bladed constant-speed propeller with a diameter of 9.2 feet (2.80 meters).

Nakajima Ki-43 Type 1 Army Fighter, called “Oscar” by the Allied forces. (The Java Gold’s Blog)

Compared to American fighters, the Oscar was lightly armed with just two synchronized 7.7 mm × 58 mm Type 89 or 12.7 mm × 81 mm Type 1 machine guns, or a combination of one 7.7 mm and one 12.7 mm gun. The 12.7 machine gun could fire explosive ammunition. (The Type 89 was a licensed version of the Vickers .303-caliber machine gun, while the design of the Type 1 was based on the Browning M1921 .50-caliber machine gun.)

The Oscar’s maximum speed was 295 miles per hour (475 kilometers per hour) at Sea Level, and 347 miles per hour (558 kilometers per hour) at 20,000 feet (6,096 meters). Its service ceiling was 37,100 feet (11,308 meters). The maximum range with a normal fuel load of 149 U.S. gallons (564 liters) was 1,180 miles (1,899 kilometers) at 1,500 feet (457 meters).

Lockheed P-38J-10-LO Lightning 42-68008, Lockheed serial number 2519. (Lockheed Martin)

The Lockheed P-38 lightning is a single-place, mid-wing, twin-engine fighter. It is an unusual configuration, with the cockpit, weapons and nose landing gear in a central nacelle, and engines, turbochargers, cooling system and main landing gear in outer “booms.” The airplane was originally designed by Clarence L. “Kelly” Johnson.

The P-38J is 37 feet, 10 inches (11.532 meters) long, with a wingspan of 52 feet, 0 inches (15.850 meters) and overall height of 9 feet, 9-11/16 inches (2.989 meters). The fighter has an empty weight of 12,700 pounds (5,761 kilograms) and maximum gross weight of 21,600 pounds (9,798 kilograms).

The P-38J was powered by two liquid-cooled, turbosupercharged 1,710.597-cubic-inch displacement (28.032 liter) Allison Engineering Company V-1710-F-17R and -F17L (V-1710-89 and -91, respectively) single overhead cam (SOHC) 60° V-12 engines with a continuous power rating of 1,100 horsepower at 2,600 r,p.m., to 30,000 feet (9,144 meters), and a takeoff/military power rating of 1,425 horsepower at 3,000 r.p.m. The counter-rotating engines drove 11 feet, 6 inches (3.505 meters) diameter, three-bladed Curtiss Electric full-feathering constant-speed propellers through a 2.00:1 gear reduction. The engines were 7 feet, 1.34 inches (2.168 meters) long, 3 feet, 0.75 inches (0.933 meters) high, 2 feet, 5.28 inches (0.744 meters) wide, and weighed 1,350 pounds (612 kilograms).

A flight of two camouflaged Lockheed P-38J Lightnings, circa 1943. Dick Bong is flying the closer airplane, P-38J-5-LO 42-67183. (Lockheed Martin)

The P-38J had a maximum speed of 420 miles per hour (676 kilometers per hour) at 26,500 feet (8,077 meters). The service ceiling was 44,000 feet (13,411 meters). Carrying external fuel tanks, the Lightning had a maximum range of 2,260 miles (3,637 kilometers).

P-38s were armed with one 20 mm Hispano M2 aircraft autocannon with 150 rounds of ammunition, and four air-cooled Browning AN-M2 .50-caliber machine guns with 500 rounds per gun. All guns are grouped close together in the nose and aimed straight ahead.

A Lockheed P-38 Lighning test fires its guns. (Lockheed Martin)

Between 1939 and 1945, Lockheed Aircraft Corporation built 10,037 P-38 Lightnings at Burbank, California. 2,970 of these were P-38Js.

Major Richard Ira Bong, Air Corps, United States Army. (Richard I. Bong Veterans Historical Center/National Endowment for the Humanities)

© 2018, Bryan R. Swopes

20 August 1944

North American Aviation Mustang Mk.I AG346 at Speke Aerodrome, Liverpool, England, November 1941. © IWM (ATP 10608C)

20 August 1944: Mustang Mk.I AG346, while flying with No. 168 Squadron, Second Tactical Air Force, Royal Air Force, from a forward airfield at Sainte-Honorine-des-Pertes, Normandy, France, was shot down near Gacé by antiaircraft fire.

The very first operational North American Mustang, AG346 (North American serial number 73-3099) was the second airplane to come off the assembly line at Inglewood, California.

After flight testing by North American’s test pilots and Royal Air Force fighter pilots Chris Clarkson and Michael “Red Knight” Crossley, AG346 was crated and then shipped to England, arriving at Liverpool, 24 October 1941. It was taken to the Lockheed facility at Speke Aerodrome (now, Liverpool John Lennon Airport, LPL) where it was reassembled and put through additional performance and flight tests.

AG346 was then assigned to an operational RAF fighter squadron. It served with Nos. 225, 63 and 26 Squadrons before being assigned to No. 41 Operations Training Unit. AG346 was returned to operations with No. 16 Squadron, and finally, No. 168 Squadron.

A North American Aviation Mustang Mk.I of No. 168 Squadron, Royal Air Force, banking over Pierrefitte-en-Cinglais, Normandy, on a tactical reconnaissance sortie, August 1944. Allied tanks can be seen on the road below. © IWM (C 4559)

The Mustang Mk.I was a new fighter built by North American Aviation, Inc., for the Royal Air Force. The RAF had contracted with NAA to design and build a fighter with a liquid-cooled Allison V-1710 12-cylinder engine. The first order from the British Purchasing Commission was for 320 airplanes, and a second order for another 300 soon followed.

The Mustang Mk.I (NAA Model NA-73) was a single-place, single-engine fighter primarily of metal construction with fabric control surfaces. It was 32 feet, 3 inches (9.830 meters) long with a wingspan of 37 feet, 5/16-inches (11.373 meters) and height of 12 feet, 2½ inches (3.721 meters). The airplane’s empty weight was 6,280 pounds (2,849 kilograms) and loaded weight was 8,400 pounds (3,810 kilograms).

North American Aviation Inc. Mustang Mk.I fighter, AG348, built for the Royal Air Force, at Mines Field, Los Angeles, California, 1941. This airplane would be transferred to the U.S. Army Air Corps as XP-51 41-038. North American Aviation, Inc., photograph. (Ray Wagner Collection/SDASM)

The Mustang Mk.I was powered by a liquid-cooled, supercharged 1,710.597-cubic-inch-displacement (28.032 liter) Allison Engineering Company V-1710-F3R (V-1710-39) single overhead camshaft (SOHC) 60° V-12 engine with four valves per cylinder and a compression ratio of 6.65:1. The engine had a takeoff rating of 1,150 horsepower at 3,000 r.p.m. at Sea Level with 45.5 inches of manifold pressure (1.51 Bar), and a war emergency rating of 1,490 horsepower with 56 inches of manifold pressure (1.90 Bar). The Allison drove a 10 foot, 9 inch (3.277 meter) diameter, three-bladed, Curtiss Electric constant-speed propeller through a 2.00:1 gear reduction. The V-1710-39 was 7 feet, 4.38 inches (2.245 meters) long, 3 feet, 0.54 inches (0.928 meters) high, and 2 feet, 5.29 inches (0.744 meters) wide. It weighed 1,310 pounds (594 kilograms).

This engine gave the Mustang Mk.I a maximum speed of 382 miles per hour (615 kilometers per hour) and cruise speed of 300 miles per hour (483 kilometers per hour). The service ceiling was 30,800 feet (9,388 meters) and range was 750 miles (1,207 kilometers).

North American Aviation Mustang Mk.I AG365 of the Air Fighting Development Unit at Duxford, Cambridgeshire, February 1942. © IWM (CH17966)

The Mustang Mk.I was equipped with four Browning .303 Mk.II machine guns, two in each wing, and four Browning AN-M2 .50-caliber machine guns, with one in each wing and two mounted in the nose under the engine.

The British would recommend that the Allison be replaced by the Rolls Royce Merlin V-12. This became the Mustang Mk.III and the U.S.A.A.F. P-51B. Eventually, over 15,000 Mustangs were built, and it was a highly successful combat aircraft. Today, after 71 years, the Mustang is one of the most recognizable of all airplanes.

AG346 was the first one to go to war.

No. 168 Squadron was a reconnaissance unit. Its motto was Rerum cognoscere causas (“To know the cause of things”)

Mustang Mk.1 of No. 168 Squadron, Royal Air Force. (RAF)
Mustang Mk.I of No. 168 Squadron, Royal Air Force. (RAF)

© 2018, Bryan R. Swopes

24 April 1939

The Curtiss XP-40 prototype at Langley Field in the original configuration. (NASA)
The Curtiss-Wright XP-40 prototype, 36-10, at Langley Field in the original configuration. Compare this to the first production P-40 Warhawk in the photograph below. (NASA)
Curtiss P-40 Warhawk 39-156. (U.S. Air Force)
Curtiss-Wright P-40 Warhawk 39-156. (U.S. Air Force)

24 April 1939: Curtiss-Wright’s prototype fighter, the XP-40 (Model 75P), was evaluated by the National Advisory Committee for Aeronautics (NACA) at the Langley Memorial Aeronautical Laboratory, Langley Field, Virginia, in March and April 1939. NACA engineers placed the XP-40 inside the Full-Scale Wind Tunnel, which was capable of accepting airplanes with wing spans of up to 40 feet (12.2 meters).

Compare this production Curtiss-Wright P-36A Hawk to the first production P-40 Warhawk in the photograph below.
Curtiss Model 81, P-40 Warhawk, 39-156. (San Diego Air and Space Museum Archive)

The airplane was a production Curtiss P-36A Hawk, serial number 38-10, which had been modified by replacing its original air-cooled Pratt & Whitney Twin Wasp S1C1-G (R-1830-17) 14-cylinder radial engine 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).

Curtiss XP-40 prototype in the NACA wind tunnel at Langley Field, Virginia, 24 April 1939. The technician at the lower left of the photograph provides scale. (NASA)
Curtiss-Wright XP-40 prototype in the NACA wind tunnel at Langley Field, Virginia, 24 April 1939. The technician at the lower left of the photograph provides scale. (NASA)

The primary benefit of the engine change was the streamlined fuselage that resulted. The new airplane was capable of a speed of 366 miles per hour (589 kilometers per hour), a 53 miles per hour (85 kilometers per hour) increase over the P-36.

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 Benjamin Scovill Kelsey flew the modified XP-40 back to Curtiss at Buffalo, New York. Its speed had been increased to 354 miles per hour (570 kilometers per hour), a 12% improvement. Other improvements were recommended which may have increased the XP-40’s speed by an additional 18 miles per hour (29 kilometers per hour). By December 1939, the airplane had been further improved and was capable of 366 miles per hour (589 kilometers per hour).

These photographs show the full-size prototype in the NACA wind tunnel at Langley, 24 April 1939. Two days later, the U.S. Army Air Corps ordered 524 airplanes as the P-40 Warhawk. By the time production ended in 1945, 13,738 Warhawks had been built.

Curtiss XP-40 in the NACA full scale wind tunnel, Langley Field, Virginia, April 1939. (NASA)
Curtiss XP-40 in the NACA full scale wind tunnel, Langley Field, Virginia, April 1939. (NASA)

© 2018, Bryan R. Swopes