19 August 1940: At Mines Field (now known as Los Angeles International Airport), the first North American Aviation B-25 twin-engine medium bomber, serial number 40-2165, took off on its first flight with test pilot Vance Breese at the controls and engineer Roy Ferren in the co-pilot’s position.
The airplane, North American model NA-62, serial number 62-2834, was developed from two earlier designs which had been evaluated by the U.S. Air Corps but rejected, and it was ordered into production without a prototype being built.
The first few B-25s built—sources vary, but 8–10 airplanes—were built with a constant dihedral wing. Testing at Wright Field showed that the airplane had a slight tendency to “Dutch roll” so all B-25s after those were built with a “cranked” wing, with the outer wing panels having very slight dihedral ¹ and giving it the bomber’s characteristic “gull wing” appearance. The two vertical stabilizers were also increased in size.
40-2165 was retained by North American for testing while the next several aircraft were sent to Wright Field.
The B-25 was named Mitchell in honor of early air power advocate Brigadier General Billy Mitchell. A total of 9,984 B-25s, F-10 reconnaissance variants and U.S. Navy and Marine Corps PBJ-1 patrol bombers were built by North American Aviation at Inglewood, California and Kansas City, Kansas. The last one, a TB-25J, remained in service with the U.S. Air Force until 1960.
Twenty-three B-25s were built before the B-25A Mitchell went into production. The B-25 was operated by a crew of five. It was 54 feet, 1 inch (16.485 meters) long with a wingspan of 67 feet, 6.7 inches (20.592 meters) and overall height of 16 feet, 4 inches (4.978 meters). The empty weight was 17,258 pounds (7,828 kilograms) and the maximum gross weight was 28,557 pounds (12,953 kilograms).
The B-25 was powered by two air-cooled, supercharged, 2,603.737-cubic-inch-displacement (42.688 liter) Wright Aeronautical Division Cyclone 14 GR2600B665 (R-2600-9) two-row 14-cylinder radial engines which were rated at 1,500 horsepower at 2,400 r.p.m., and 1,700 horsepower at 2,600 r.p.m. for takeoff. These engines (also commonly called “Twin Cyclone”) drove three-bladed Hamilton Standard Hydromatic variable-pitch propellers through 16:9 gear reduction. The R-2600-9 was 5 feet, 3.1 inches (1.603 meters) long and 4 feet, 6.26 inches (1.378 meters) in diameter. It weighed 1,980 pounds (898 kilograms).
The medium bomber had a maximum speed of 322 miles per hour (518 kilometers per hour) at 15,000 feet (4,572 meters) and a service ceiling of 30,000 feet (9,144 meters). It could carry a 3,000 pound bomb load 2,000 miles (3,219 kilometers).
Defensive armament consisted of three air-cooled Browning M2 .30-caliber aircraft machine guns and one Browning AN-M2 .50-caliber machine gun.
After testing was completed, B-25 40-2165 was retained by North American and modified as a company transport. On 8 January 1945, flown by Edgar A. Stewart, the airplane suffered an engine failure and made a forced landing at Mines Field—the location of its first flight. The prototype B-25 was damaged beyond repair.
¹ The wing center section of the B-25H and B-25J has 4° 38′ 23″ dihedral. The outer sections have 0° 21′ 39″. The wing has 2° 29′ 37″ negative twist.
26 May 1942: The prototype Northrop XP-61-NO Black Widow, 41-19509, made its first flight at Northrop Field, Hawthorne, California, with free-lance test pilot Vance Breese at the controls. (Breese had taken the North American Aviation NA-73X, prototype of the Mustang, for its first flight, 20 October 1940.)
The first American airplane designed specifically as a night fighter, the XP-61 was the same size as a medium bomber: 48 feet, 11.2 inches (14.915 meters) long with a wingspan of 66 feet (20.117 meters) and overall height of 14 feet, 8.2 inches (4.475 meters). The prototype was equipped with a mockup of the top turret. Its empty weight was 22,392 pounds (10,157 kilograms), gross weight of 25,150 pounds (11,408 kilograms) and maximum takeoff weight of 29,673 pounds (13,459 kilograms).
The XP-61 was powered by two air-cooled, supercharged, 2,804.4-cubic-inch-displacement (45.956 liter) Pratt & Whitney Double Wasp SSB2-G (R-2800-10) two-row, 18-cylinder radial engines with a compression ratio of 6.65:1. The R-2800-10 had a Normal Power rating of 1,550 horsepower at 2,550 r.p.m. at 21,500 feet (6,553 meters), and 2,000 horsepower at 2,700 r.p.m. for takeoff, burning 100-octane gasoline. The R-2800-10 had a 2:1 gear reduction and drove four-bladed Curtiss Electric constant-speed propellers which had a 12 foot, 2 inch (3.708 meter) diameter. The R-2800-10 was 4 feet, 4.50 inches (1.334 meters) in diameter, 7 feet, 4.47 inches (2.247 meters) long, and weighed 2,480 pounds (1,125 kilograms), each.
The prototype Black Widow had a top speed of 370 miles per hour (595 kilometers per hour) at 29,900 feet (9,114 meters) and a service ceiling of 33,100 feet (10,089 meters). The maximum range was 1,450 miles (2,334 kilometers).
The night fighter was crewed by a pilot, a gunner and a radar operator. A large Bell Laboratories-developed, Western Electric-built SCR-720 air search radar was mounted in the airplane’s nose. The gunner sat above and behind the pilot and the radar operator was in the rear fuselage.
The Black Widow was armed with four Browning AN-M2 .50-caliber machine guns in a remotely-operated upper turret, and four AN-M2 20 mm aircraft automatic cannons, grouped close together in the lower fuselage and aimed directly ahead. This was a superior arrangement to the convergent aiming required for guns mounted in the wings. The fire control system was similar to that used by the B-29 Superfortress. The guns could be fired by either the gunner or the radar operator. The Black Widow carried 200 rounds of ammunition for each cannon,
The XP-61 was built with a center “gondola” for the crew, radar and weapons, with the engines outboard in a twin-boom configuration, similar the the Lockheed P-38 Lightning. The Black Widow did not use ailerons. Instead, it had spoilers mounted on the upper wing surface outboard of the engines. Roll control was achieved by raising a spoiler, decreasing lift on that wing and causing it to drop. A similar system was employed on the Boeing B-52 Stratofortress ten years later.
The P-61 got its nickname, Black Widow, from the glossy black paint scheme that scientists at the Massachusetts Institute of Technology (M.I.T.) had determined was the best camouflage for a night fighter. Over 700 P-61s were built, with 36 built as the F-15 photo reconnaissance variant. They served in both the Pacific and European Theaters during World War II, and were also used during the Korean War. After the war, the radar-equipped fighter was used for thunderstorm penetration research.
20 November 1940: North American Aviation’s Chief Test Pilot, Paul Baird Balfour, made his first flight in the NA-73X, NX19998, prototype for a Royal Air Force fighter, the Mustang Mk.I.
Vance Breese was the free-lance test pilot who made the first seven flights in the new airplane. Breese claimed to have made a bet with North American executives that Balfour would crash the prototype on his first flight.
This flight was scheduled to be a high speed test. Edgar Schmued, the designer, offered to show Balfour around the airplane. “Before this flight, I asked Balfour to get into the airplane and go through the routine of a takeoff and flight. He responded that one airplane is like another and he would not need the routine checkout.”
The ground crew started the NA-73X’s 1,150 horsepower Allison V-1710-39 liquid-cooled V-12 engine at 5:40 a.m. and let it warm up to normal operating temperature. When it was restarted just prior to Paul Balfour’s flight, “it was a little hard to start,” according to Olaf Anderson, the airplane’s mechanic.
Balfour took off from Mines Field at about 7:10 a.m. After about twelve minutes of flight, the Allison stopped running. Balfour was too far from Mines Field to make it back to the runway. He landed in a plowed field west of Lincoln Boulevard. When the tires hit the soft surface, the prototype flipped over. Balfour was not hurt and was able to crawl out of the upside-down wreck.
The Civil Aeronautics Board report described the damage as “engine housing broken, both wingtips damaged, tail surfaces damaged, top of fuselage damaged, and other miscellaneous damage.” The NA-73X had accumulated just 3 hours, 20 minutes of flight.
Vance Breese won his bet.
According to the C.A.B. investigation, the engine had stopped due to fuel starvation when Balfour neglected to select another tank.
The prototype was taken back to the factory and rebuilt. It would become the famous Mustang, one of the most significant aircraft of World War II.
Robert C. Chilton was hired as the new Chief Test Pilot. He would continue testing the Mustang developments throughout the war. Chilton made his first flight in NA-73X on 3 April 1941.
Paul Balfour continued to work for North American Aviation, testing the NA-40 and NA-40B prototypes and the B-25 Mitchell medium bomber. He later served in the United States Air Force.
Paul Baird Balfour was born 5 July 1908 in Washington State. He was the son of Fred Patrick Balfour and Edna May Baird Balfour. Balfour attended two years of college.
Paul Balfour entered the U.S. Army Air Corps (prior to 1930). He was stationed at Rockwell Field, San Diego, California.
Balfour married Martha Lillette Cushman of Coronado, California, at Yuma, Arizona, 6 June 1930.
Balfour began working as a test pilot for North American Aviation, Inc., 1 March 1936.
On 2 July 1938, he married Lois Tresa Watchman at Kingman, Arizona. They would have two children.
On 9 November 1951, Major Paul B. Balfour, U.S. Air Force, attached to the 1002nd Inspector General Group at Norton Air Force Base, California, was flying a North American VB-25J, 44-30955, a transport conversion of a B-25J-30-NC Mitchell medium bomber.
Shortly after takeoff, at about 10:00 a.m., the airplane developed engine trouble. Unable to return to Norton, Balfour attempted a belly landing at a small private airfield. Witness saw that the airplane’s left engine was idling, and its propeller was feathered. As he approached, the airplane was blocked by a windbreak of eucalyptus trees bordering U.S. Route 66. Balfour banked away from the trees but the B-25 crashed in an orange grove along Bloomington Avenue in Rialto, approximately 7 miles (11 kilometers) north of Norton.
Balfour, still buckled in his seat, was thrown clear of the burning wreck and landed in the street. One man on board was killed and two others seriously injured. Balfour died in a hospital three hours later. He was 41 years old. Major Balfour was buried at the Inglewood Park Cemetery, Inglewood, California.
26 October 1940: At Mines Field, Los Angeles, California (now, Los Angeles International Airport), free lance test pilot Vance Breese took the prototype North American Aviation NA-73X, civil registration NX19998, on a five-minute first flight. Later in the day, Breese flew the NA-73X another ten minutes. He would make six more test flights between 26 October and 13 November, totaling approximately 3 hours, 30 minutes of flight time.
With Great Britain at war with Nazi Germany, the Royal Air Force was the primary defender of the island nation. Airplane manufacturers were turning out Hawker Hurricanes and Supermarine Spitfires as rapidly as possible, but they were barely keeping up with combat losses. England needed more fighters. They had taken over an order for Curtiss-Wright Hawk 81-A1 fighters which had been built for France, but which had not been shipped by the time France surrendered. The RAF called these fighters the Tomahawk Mark I (P-40 Warhawk in U.S. service).
The British Purchasing Commission asked North American Aviation in Los Angeles, California, to build additional Tomahawks under license from Curtiss-Wright. North American countered with a proposal to design a completely new and superior fighter around the P-40’s Allison V-12 engine, and begin production in no more time than it would take to get a P-40 production line up and running. The Purchasing Commission agreed, and with a letter of understanding, North American began work on the NA-73X on 1 May 1940. They were to produce 320 fighters before 30 September 1941, approximately 50 per month, at a total price of $14,746,964.35.
In a contract amendment dated 9 December 1940, the British Purchasing Commission directed that the NA-73 would be identified by the name, “Mustang.”
The prototype NA-73X, North American serial number 73-3097, was a single-seat, single-engine, low wing monoplane with retractable landing gear. It was primarily of metal construction, though the flight control surfaces were fabric covered. The airplane was designed for the maximum reduction in aerodynamic drag. The fuselage panels were precisely designed and very smooth. Flush riveting was used. The Mustang was the first airplane to use a laminar-flow wing. The coolant radiator with its intake and exhaust ducts was located behind and below the cockpit. As cooling air passed through the radiator, it was heated and expanded, so that as it exited, it actually produced some thrust.
The prototype was 32 feet, 2–5/8 inches (9.820 meters) long, with a wing span of 37 feet, 5/16 inch (11.286 meters). Empty weight of the NA-73X was 6,278 pounds (2,848 kilograms) and normal takeoff weight was 7,965 pounds (3,613 kilograms).
The NA-73X was powered by a liquid-cooled, supercharged, 1,710.60-cubic-inch-displacement (28.032 liter) Allison Engineering Company V-1710-F3R (V-1710-39) single overhead cam 60° V-12 engine, with a compression ratio of 6.65:1 and a single-stage, single-speed supercharger. This was a right-hand tractor engine (the V-1710 was built in both right-hand and left-hand configurations) which drove a 10 foot, 6 inch (3.200 meter) diameter, three-bladed, Curtiss Electric constant-speed propeller through a 2.00:1 gear reduction.
The V-1710-39 had a Normal Power rating of 880 horsepower at 2,600 r.p.m. at Sea Level; Take Off Power rating of 1,150 horsepower at 3,000 r.p.m. at Sea Level, with 44.5 inches of manifold pressure (1.51 Bar), 5 minute limit; and a War Emergency Power rating of 1,490 horsepower at 3,000 r.p.m., with 56 inches of manifold pressure (1.90 Bar). The V-1710-F3R was 3 feet, ¾ inches (0.934 meters) high, 2 feet, 5-9/32 inches (0.744 meters) wide and 7 feet, 1-5/8 inches (2.175 meters) long. It had a dry weight of 1,310 pounds (594 kilograms).
The NA-73X had a maximum speed of 382 miles per hour (615 kilometers per hour) at 13,700 feet (4,176 meters). The service ceiling was 32,000 feet (9,754 meters). The fuel capacity was 180 gallons (681.37 liters), giving the airplane a range of 750 miles (1,207 kilometers).
NX19998 was substantially damaged on 20 November 1940 when North American’s Chief Test Pilot, Paul B. Balfour, unable to make it back to Mines Field after the Allison engine failed, made a forced landing in a plowed field just west of Lincoln Boulevard. The prototype flipped over and landed upside down. Sources differ as to the cause of the engine failure, with some citing carburetor icing and others suggesting that Balfour failed to switch fuel tanks and the engine stopped running due to fuel starvation. Balfour was replaced by Robert C. Chilton and NA-73X was rebuilt.
Bob Chilton said that “. . . NA-73X was a clean-flying aircraft with no bad vices. It was quite pleasant in the air and handled very similar to later production articles.”
There was only one NA-73X prototype. Its status is not known. Chilton recalled, “. . . NA-73X was just pushed aside after it had been retired from its last flight. It probably ended up on the company’s junk pile, but I do not recall seeing it there.” The prototype may have been given to a local industrial trade school.
Vance Breese was born 20 April 1904 at Keystone, Washington, He was the first of five children of Lee Humbert Breese, a machinist, and Anna E. Dixon Breese.
Breese founded the Breese Aircraft Company in 1926, based at San Francisco, California, and then, as the Breese-Wilde Corporation, moved to Oregon. The company produced the Breese-Wilde Model 5, a single-engine light airplane. Two of these, Aloha and Pabco Flyer, flew in the notorious 1927 Dole Air Race from Oakland, California, to Honolulu, Hawaii. Pabco Flyer crashed on takeoff when its landing gear collapsed. Aloha finished in second place.
Breese formed a partnership with Gerard Vultee in 1932, with the Airplane Development Corporation at Detroit Michigan. They produced the Vultee V-1A, an 8 passenger light transport. He was also involved in an express mail company, Air Express Corporation.
Vance Breese was well known as a test pilot, making a number of first flights and conducting flight tests for various airplane manufacturers. As a test pilot, Breese pioneered the use of recording equipment during flight testing. He used a Dictaphone to record his notes, and a cine camera to film the instruments during the flight.
Breese was married three times. He first married Miss Kathryn (“Kitty”) M. McConnell in 1922. They divorced. Later, Breese married Eleanor Louise Buckles at Los Angeles, California, 18 November 1946. They had a son, Vance Breese, Jr., who became a well-known motorcycle racer and land speed record holder. They divorced in 1967. Breese then married Mireille E. Demartelley (AKA Mireille E. Hunt), 13 July 1967, at Santa Barbara, California.
He died at Santa Monica, California, 26 June 1973, at the age of 69 years. He is an Honorary Fellow of the Society of Experimental Test Pilots.