23 April 1941: At North American Aviation’s Inglewood, California factory, test pilot Louis S. Wait takes the very first production Mustang Mk.I, AG345, (c/n 73-3098) for its first flight. The Royal Air Force had contracted with NAA to design and build a new fighter with an Allison V-1710 supercharged 12-cylinder engine producing 1,200 horsepower. 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).
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 cam (SOHC) 60° V-12 engine which turned a 10 foot, 9 inch (3.277 meter) diameter, three-bladed, Curtiss Electric constant-speed propeller through a 2.00:1 gear reduction. 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).
This 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).
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 Mk.I was 30 m.p.h. (48 kilometers per hour) faster than its contemporary, the Curtiss P-40 Warhawk, though both used the same engine. Below 15,000 feet (4,572 meters), the Mustang was also 30–35 m.p.h (48–56 kilometers per hour) faster than a Supermarine Spitfire, which had the more powerful Roll-Royce Merlin V-12.
Two Mustang Mk.Is, AG348 and AG354, were taken from the first RAF production order and sent to Wright Field for testing by the U.S. Army Air Force. These airplanes, assigned serial numbers 41-038 and 41-039, were designated XP-51. They would be developed into the legendary P-51 Mustang. In production from 1941 to 1945, a total of 16,766 Mustangs of all variants were built.
AG345 was retained by North American Aviation for long term testing. It was stricken off charge 3 December 1946.
6 April 1938:¹ After being shipped by truck from the Bell Aircraft Company factory at Buffalo, New York, the XP-39 prototype, 38-326, made its first flight at Wright Field, Ohio, with test pilot James Taylor ² in the cockpit.
The Bell XP-39 Airacobra was a single-place, single-engine prototype fighter with a low wing and retractable tricycle landing gears. The airplane was primarily built of aluminum, though control surfaces were fabric covered.
As originally built, the XP-39 was 28 feet, 8 inches (8.738 meters) long with a wingspan of 35 feet, 10 inches (10.922 meters). The prototype had an empty weight of 3,995 pounds (1,812 kilograms) and gross weight of 5,550 pounds (2,517 kilograms).
The XP-39 was unarmed, but it had been designed around the American Armament Corporation T9 37 mm autocannon, later designated Gun, Automatic, 37 mm, M4 (Aircraft).³ The cannon and ammunition were in the forward fuselage, above the engine driveshaft. The gun fired through the reduction gear box and propeller hub.
The XP-39 was originally powered by a liquid-cooled, turbosupercharged and supercharged 1,710.597-cubic-inch-displacement (28.032 liter) Allison Engineering Co. V-1710-E2 (V-1710-17), a single overhead cam (SOHC) 60° V-12 engine with a compression ratio of 6.65:1. The V-1710-17 had a Maximum Continuous Power rating of 1,000 horsepower at 2,600 r.p.m. at 25,000 feet (7,620 meters), and Takeoff/Military Power rating of 1,150 horsepower at 3,000 r.p.m. at 25,000 feet, burning 91 octane gasoline. The engine was installed in an unusual configuration behind the cockpit, with a two-piece drive shaft passing under the cockpit and turning the three-bladed Curtiss Electric constant-speed propeller through a remotely-mounted 1.8:1 gear reduction gear box. The V-1710-17 was 16 feet, 1.79 inches (4.922 meters) long, including the drive shaft and remote gear box. It was 2 feet, 11.45 inches (0.900 meters) high, 2 feet, 5.28 inches (0.744 meters) wide and weighed 1,350 pounds (612 kilograms).
During the test flight, Taylor flew the XP-39 to 390 miles per hour (628 kilometers per hour) at 20,000 feet (6,096 meters). The service ceiling was 32,000 feet (9,754 meters).
After initial flight testing, the XP-39 was sent to NACA at Langley Field, Virginia for wind tunnel tests. Improvements in aerodynamics were recommended and the airplane was rebuilt as the XP-39B with an Allison V-1710-E5 (V-1710-37) engine. The turbosupercharger had been removed, which reduced the airplane’s power at altitudes above 15,000 feet (4,572 meters). The V-1710-37 had a maximum power of 1,090 horsepower at 3,000 r.p.m. at 13,300 feet (4,054 meters). This resulted in the P-39 being used primarily as a ground-attack weapon. The XP-39B, with test pilot George Price in the cockpit, was damaged when when its landing gear did not fully extend, 6 January 1940. It was repaired and test flights resumed.
On 6 August 1940, Captain Ernest K. Warburton stalled the prototype on landing. The impact resulted in significant structural damage, beyond economic repair. The airplane was later scrapped.
9,584 Bell P-39 Airacobras were built during World War II. More than half were sent to the Soviet Union.
¹ Reliable sources indicate the date of the first flight as both 1938 and 1939. The Bell Helicopter Company web site, “The History of Bell Helicopter: 1935–1949” states 1938.
² James Taylor may have been Lieutenant Commander James Blackstone Taylor, Jr., (1897–1942), Naval Aviator No. 437, a very well-known U.S. Navy test pilot.
³ The 37-mm Aircraft Gun Matériel M4 is a recoil-operated aircraft weapon designed by John M. Browning. It has an overall length of 7 feet, 5 inches (2.26 meters). The barrel, or “tube,” is 5 feet, 5 inches (1.65 meters) long with a caliber of 1.457 inches (37.0 millimeters) and weighs 55 pounds (25 kilograms). The barrel is part of the recoiling section of the gun and moves rearward 9-5/8 inches (245 millimeters). The weight of the gun with a loaded 30-round magazine is 306.4 pounds (138.98 kilograms). The M4 fires a high-explosive tracer round with a muzzle velocity of 2,000 feet per second (607 meters per second). Each M54 shell is 9.75 inches (248 millimeters) long and weighs 1.93 pounds, of which the projectile makes up 1.34 pounds (0.608 kilograms). The cannon has a cyclic rate of fire of 125–150 rounds per minute.
4 April 1917: Sous-Lieutenant René Pierre Marie Dorme of the Aéronautique Militaire (French Air Service) made the first flight of the famous World War I fighter, the SPAD S.XIII C.1.
Lieutenant Dorme was an ace with 18 confirmed victories. In the next seven weeks, he shot down another five enemy aircraft.
Designed by Technical Director Louis Béchéreau and manufactured by Société Pour L’Aviation et ses Dérivés as well as eight other companies, this was an improved and slightly larger version of the earlier SPAD S.VII C.1. It used a more powerful Hispano-Suiza 8Ba engine instead of the S.VII’s 8Aa, with an increase of 50 horsepower. (Later versions used 8Be engines.) Armament was increased from a single .303-caliber Vickers machine guns to two.
The SPAD was faster than other airplanes of the time and it had a good rate of climb. Though a product of France, it was used by both the Royal Flying Corps and the U.S. Army Air Service. In France, the airplane type now considered a “fighter” was called a chasseur (“hunter”). The letter “C-” in the SPAD’s designation reflects this. The “-.1” at the ending indicates a single-place aircraft.
The SPAD S.XIII C.1 was a single-seat, single-engine, two-bay biplane constructed of a wooden framework with a doped fabric covering. Sheet metal covered the engine and cockpit.
The S.XIII was 20 feet, 4 inches (6.198 meters) long.¹ The upper and lower wings had equal span and chord. The span was 26 feet, 3¾ inches (8.020 meters) and chord, 4 feet, 7-1/8 inches (1.400 meters). The vertical spacing between the wings was 3 feet, 10½ inches (1.181 meters), and the lower wing was staggered 1¼° behind the upper. Interplane struts and wire bracing was used to reinforce the wings. The wings had no sweep or dihedral. The angle of incidence of the upper wing was 1½° and of the lower, 1°. Only the upper wing was equipped with ailerons. Their span was 7 feet, 3½ inches (2.222 meters), and their chord, 1 foot, 7½ inches (0.495 meters). The total wing area was 227 square feet (21.089 square meters).
The horizontal stabilizer had a span of 10 feet, 2 inches (3.099 meters) with a maximum chord of 1 foot, 8¾ inches (0.527 meters). The height of the vertical fin was 2 feet, 7/8-inch (0.876 meters) and it had a maximum length of 3 feet, 11¼ inches (1.200 meters). The rudder was 3 feet, 10-5/8 inches high (1.184 meters) with a maximum chord of 2 feet, 2 inches (0.660 meters).
The SPAD S.XIII C.1 had fixed landing gear with two pneumatic tires. Rubber cords (bungie cords) were used for shock absorption. The wheel track was 4 feet, 10¾ inches (1.492 meters). At the tail was a fixed skid.
The airplane had an empty weight of 1,464 pounds (664 kilograms), and gross weight 2,036 pounds (924 kilograms).
Initial production SPAD XIIIs were powered by a water-cooled 11.762 liter (717.769-cubic-inch displacement), La Société Hispano-Suiza 8Ba single overhead cam (SOHC) left-hand-tractor 90° V-8 engine. It was equipped with two Zenith down-draft carburetors and had a compression ratio of 5.3:1. The 8Ba was rated at 150 cheval vapeur (148 horsepower) at 1,700 r.p.m., and 200 cheval vapeur (197 horsepower) at 2,300 r.p.m. It drove a two-bladed, fixed-pitch, wooden propeller with a diameter of 2.50 meters (8 feet, 2.43 inches) through a 0.585:1 gear reduction. (The 8Be engine had a 0.75:1 reduction gear ratio and used both 2.50 meter and 2.55 meter (8 feet, 4.40 inches) propellers.) The Hispano-Suiza 8Ba was 1.36 meters (4 feet, 5.5 inches) long, 0.86 meters (2 feet, 9.9 inches) wide and 0.90 meters (2 feet, 11.4 inches) high. It weighed 236 kilograms (520 pounds).
The airplane had a main fuel tank behind the engine, with a gravity tank located in the upper wing. The total fuel capacity was 183 pounds (83 kilograms), sufficient for 2 hours, 30 minutes endurance at full throttle at 10,000 feet (3,048 meters), including climb. There was also a 4.5 gallon (17 liters) lubricating oil tank.
The SPAD S.XIII had a maximum speed of 135 miles per hour (218 kilometers per hour) at 6,560 feet (2,000 meters) and a service ceiling of 21,815 feet (6,650 meters).
The chasseur was armed with two fixed, water-cooled, .303-caliber (7.7 mm) Vickers Mk.I machine guns with 400 rounds of ammunition per gun, synchronized to fire forward through the propeller arc. Because of the cold temperatures at altitude, the guns’ water jackets were not filled, thereby saving considerable weight.
The SPAD S.XIII was produced by nine manufacturers. 8,472 were built. Only four are still in existence.
The airplane in the photograph above is SPAD S.XIII C.1, serial number 16594. It was built in October 1918 by Kellner et ses Fils, a piano maker in Paris, France. It did not see combat, but was shipped to the United States at the end of the War and was stationed at San Diego, California. It was restored by the National Museum of the United States Air Force and is painted in the markings of the airplane flown by Captain Edward V. Rickenbacker, commanding officer of the 94th Aero Squadron, American Expeditionary Forces. It is on display at NMUSAF, Wright-Patterson Air Force Base, Ohio.
The airplane in the photograph below is another SPAD S.XIII C.1, serial number 7689, also built by Kellner et ses Fils, in August 1918. It was sent to the 22nd Aero Squadron at Colombey-les-Belles and assigned to Lieutenant Arthur Raymond Brooks. Brooks’ fiancée attended Smith College and he named the SPAD Smith IV in her honor. With this airplane, Lieutenant Brooks shot down six enemy airplanes. Other pilots also flew it to shoot down another five.
After the War came to an end, 7689 was shipped to the United States and used in a Liberty Bond fund-raising tour. In December 1919, the United States Army gave the fighter to the Smithsonian Institution. It was restored at the Paul E. Garber Center, 1984–1986, and remains in the collection of the National Air and Space Museum.
René Dorme fought 120 aerial engagements, many while flying a SPAD S.VII C.1. He is officially credited with 22 victories, and may have shot down as many as 59 enemy aircraft. His personal airplane was marked with a green Cross of Lorraine. He was a Chevalier de la légion d’honneur, and had been awarded the Médalle Militaire and the Croix de Guerre with 17 Palms. Dorme was killed in action 25 May 1917 when his SPAD VII was shot down by Oberleutnant Heinrich Kroll of Jasta 9 at Fort de la Pompelle near Reims.
¹ Dimensions, weights, capacities and performance data cited above refer to SPAD S.XIII C.1 serial number 17956 (A.S. 94101), which was tested at McCook Field, Dayton, Ohio (Project Number P-154), 1921.
3 April 1941: North American Aviation test pilot Robert Creed Chilton takes his first flight—a one hour familiarization—in the company’s prototype of a new fighter for the Royal Air Force, the NA-73X, NX19998, at Mines Field. (Mines would later become Los Angeles International Airport, LAX.)
The airplane’s had first been flown by free-lance test pilot Vance Breese, 26 October 1940, and he had flown it several times. North American’s Chief Test Pilot, Paul Baird Balfour, on his first flight in NX19998, ran out of fuel and crash landed in a plowed field 150 yards (137 meters) west of the airfield, 20 November 1940. The prototype had flown just 3 hours, 20 minutes.
The NA-73X was repaired and Bob Chilton was assigned to complete the testing program. The airplane would become the legendary P-51 Mustang, and Chilton would continue to conduct the majority of flight testing on its improvements and modifications.
Robert Creed Chilton was born 6 February 1912 at Eugene, Oregon, the third of five children of Leo Wesley Chilton, a physician, and Edith Gertrude Gray. He attended Boise High School in Idaho, graduating in 1931. Chilton participated in football, track and basketball, and also competed in the state music contest. After high school, Chilton attended the University of Oregon where he was a member of the Sigma Chi fraternity (ΣΧ). He was also a member of the Reserve Officers Training Corps (ROTC).
Bob Chilton enlisted as an Aviation Cadet in the U.S. Army Air Corps, 25 June 1937. He was trained as a fighter pilot at Randolph Field and Kelly Field in Texas, and was commissioned as a Second Lieutenant in 1938. Lieutenant Chilton was assigned to fly the Curtiss P-36 Hawk with the 79th Pursuit Squadron, 20th Pursuit Group, at Barksdale Field, Louisiana. Because of a medical condition, he was released from active duty, 1 April 1939.
At some time prior to 1940, Bob Chilton, married his first wife, Catherine. They lived in Santa Maria, California, where he worked as a pilot at the local airport.
In January 1941, Chilton went to work as a production test pilot for North American Aviation, Inc., Inglewood, California. After just a few months, he was assigned to the NA-73X.
Chilton married his second wife, Betty W. Shoemaker, 15 November 1951.
On 10 April 1952, Bob Chilton returned to active duty with the U.S. Air Force, with the rank of lieutenant colonel. He served as Chief of the Repulic F-84 and F-105 Weapons System Project Office, Air Material Command, at Wright-Patterson Air Force Base, Dayton, Ohio, until 9 March 1957.
From 1958, Chilton was a vice president for Horkey-Moore Associates, an engineering research and development company in Torrance, California, founded by former North American aerodynamacist Edward J. Horkey. In 1961, he followed Horkey to the Space Equipment Corporation, parent company of Thompson Industries and Kerr Products, also located in Torrance. Chilton served as corporate secretary and contracts administrator.
Chilton married his third wife, Wilhelmina E. Redding (Billie E. Johnson) at Los Angeles, 26 July 1964. They divorced in 1972.
In 1965, Bob Chilton returned to North American Aviation as a flight test program manager. He retired in 1977.
Robert Creed Chilton died at Eugene, Oregon, 31 December 1994, at the age of 82 years.
31 March 1945: Messerschmitt AG test pilot and technical inspector Hans Fay (1888–1959) defected to the Allies at Frankfurt/Rhein-Main Airfield, Frankfurt, Germany. He brought with him a brand new Me 262 A-1 twin-engine jet fighter.
Fay had been waiting for an opportunity to bring an Me 262 to the Americans, but feared reprisals against his parents. When he learned that the U.S. Army controlled their town, he felt that it was safe to go ahead with his plan.
On 31 March, Fay was ordered to fly one of twenty-two new fighters from the Me 262 assembly factory at Schwäbisch-Hall to a safer location at Neuburg an der Donau, as they were in danger of being captured by advancing Allied forces. His airplane was unpainted other than low visibility Balkenkreuz markings on the wings and fuselage, and standard Luftwaffe markings on the vertical fin. Fay was the fourth to take off, but instead of heading east-southeast toward Neuburg, he flew north-northwest to Frankfurt, arriving there at 1:45 p.m.
The Messerchmitt Me 262 Schwalbe was the first production jet fighter. It was a single-place, twin-engine airplane with the engines placed in nacelles under the wings. It was 34 feet, 9 inches (10.592 meters) long with a wingspan of 41 feet (12.497 meters) and overall height of 11 feet, 4 inches (3.454 meters). According to Fay, the fighter’s empty weight was 3,760 kilograms (8,289 pounds) and the maximum gross weight was 7,100 kilograms (15,653 pounds) at engine start.
The Me 262 A-1 was powered by two Junkers Jumo TL 109.004 B-1 turbojet engines. The 004 was an axial-flow turbojet with an 8-stage compressor section, six combustion chambers and single-stage turbine. The 004 engine case was made of magnesium for light weight, but this made it vulnerable to engine fires. The engine was designed to run on diesel fuel, but could also burn gasoline or, more commonly, a synthetic fuel produced from coal, called J2. The engine was first run in 1940, but was not ready for production until 1944. An estimated 8,000 engines were built. The 004 B-1 produced 1,984 pounds of thrust (8.825 kionewtons) at 8,700 r.p.m.
During interrogation, Hans Fay said that for acceptance, the production Me 262 was required to maintain a minimum of 830 kilometers per hour (515 miles per hour) in level flight, and 950 kilometers per hour (590 miles per hour) in a 30° dive. The fighter’s cruise speed was 750 kilometers per hour (466 miles per hour).
A number of factors influenced the Me 262’s maximum range, but Fay estimated that the maximum endurance was 1 hour, 30 minutes. U.S. Air Force testing establish the range as 650 miles (1,046 kilometers) and service ceiling at 38,000 feet (11,582 meters).
It was armed with four 30 mm Rheinmetall-Borsig MK 108 autocannons with a total of 360 rounds of ammunition. It could also be armed with twenty-four R4M Orkan 55 mm air-to-air rockets. Two bomb racks under the wings could each be loaded with a 500 kilogram (1,102 pounds) bomb.
1,430 Me 262s were produced. They entered service during the summer of 1944. Luftwaffe pilots claimed 542 Allied airplanes shot down with the Me 262.
Hans Fay’s Messerschmitt Me 262 A-1, WNr. 111711, was transported to the United States and was tested at Wright Field, Dayton, Ohio.
711 was lost during a test flight, 20 August 1946, when one of its engines caught fire. The test pilot, Lieutenant Walter J. “Mac” McAuley, Jr., U.S. Army Air Corps, safely bailed out. The Me 262 crashed 2 miles (3.2 kilometers) east of Lumberton, Ohio, and was completely destroyed.