North American Aviation NA-246 Sabreliner prototype, N4060K, during its first flight, 16 September 1958. (North American Aviation, Inc.)
16 September 1958: At Palmdale, in the high desert of southern California, the prototype North American Aviation, Inc., Model NA-246 Sabreliner, N4060K, took off on its first flight. The test pilots were James O’Connor (“J.O.”) Roberts, Jr., and George Mace. Following the flight, Roberts said, “The airplane handled exceptionally well in every maneuver we tried.”
The Sabreliner had been designed and built at North American’s expense to meet the U.S. Air Force specification for the UTX, a twin-engine jet that would be primarily used as a trainer for Air Force pilots in non-flying assignments but who needed to remain proficient. It could also be used as a passenger and cargo transport.
The NA-246 was flown by two pilots and could carry up to four passengers in “club seating.”
In October 1958, the Air Force ordered the Model 265 Sabreliner into production, designated T-39A-1-NA (Serial numbers 59-2868 to -2871). This aircraft could carry up to 7 passengers. In 1962, a commercial variant of the T-39A, the Model 265 Sabreliner, was certified by the Federal Aviation Administration.
North American Aviation Model 256, N4060K, during its first flight, 16 September 1958. (North American Aviation, Inc.)
The T-39A was 44 feet (13.411 meters) long, with a wingspan of 44 feet, 6 inches (13.564 meters) and overall height of 16 feet (14.874 meters). The wings were swept at 28°. It had an empty weight of approximately 9,250 pounds (4,196 kilograms) and maximum takeoff weight of 17,760 pounds (8,056 kilograms).
The Model 246 prototype was powered by General Electric J85 turbojet engines which produced about 2,000 pounds of thrust (8.90 kilonewtons). The the production T-39A used Pratt & Whitney J60-P-3 engines, rated at 3,000 pounds (13.34 kilonewtons) for takeoff.
The T-39A had a maximum allowable airspeed (VMO) of 350 knots, indicated (KIAS) (403 miles per hour/648 kilometers per hour) from Sea Level to 21,100 feet (6,431 meters). Above that altitude, speed was restricted to 0.77 Mach.
North American Aviation T-39A-1-NA, 62-4478, at the National Museum of the United States Air Force.. (U.S. Air Force)
The prototype was issued an Airworthiness Certificate by the Federal Aviation Administration 25 April 1958. The registration was cancelled 30 June 1970.
James O’Connor Roberts, Jr. (Test & Research Pilots, Flight Test Engineers)
James O’Connor Roberts, Jr., was born 17 April 1924 at Washington, D.C. He was the second son of James O’Connor Roberts, an attorney employed by the United States government, and Leah Irene Harris Roberts. He attended the Peddie School in Highstown, New Jersey, and Yale University, where he was a member of the Kappa Phi Sigma (ΚΦΣ) and Chi Psi (ΧΨ) fraternities.
Roberts enlisted in the United States Army Air Forces as an aviation cadet in February 1943.¹ He had blond hair and blue eyes, was 5 feet, 10½ inches (1.79 meters) tall and weighed 145 pounds (65.8 kilograms). He graduated from pilot training 7 January 1944 and was commissioned as a second lieutenant.
Second Lieutenant James O. Roberts, Jr., married Miss Evelyn Meryle Foss Johnson 19 January 1944 at the Walter Reed Memorial Chapel in Washington, D.C. The ceremony was officiated by Chaplain George F. Cotton. They would have four sons. (Mrs. Roberts later died and he remarried.)
Lieutenant Roberts was assigned to the Aleutian Islands where he flew the Curtiss-Wright P-40 Warhawk.
Following World War II, Lieutenant Roberts returned to Yale to complete his studies, graduating in 1946. He majored in Sociology.
North American Aviation F-86A-5-NA Sabre 48-273, 335th Fighter-Interceptor Squadron, 4th Fighter-Interceptor Group, in the markings of the Silver Sabres Aerobatic Team, at Langley Air Force Base, circa 1950. (U.S. Air Force)
Remaining in the Air Force after the war, he transitioned to the North American P-51 Mustang and the Lockheed P-80 Shooting Star. Assigned to the 4th Fighter Group at Andrews Air Force Base, he was a member of the USAF Champion Gunnery Team and the Silver Sabres Aerobatic Team, flying “slot” and solo. The team flew the North American Aviation F-86A Sabre.
4th Fighter-Interceptor Group North American Aviation F-86A Sabres at Suwon, Korea, June 1951. (U.S. Department of Defense VIRIN: HD-SN-99-03072)
The 4th Fighter-Interceptor Group deployed to Korea in 1950. On 22 December 1950, Captain Roberts was flying one of eight F-86As in an air battle against fifteen Mikoyan-Gurevich MiG-15 fighters. Roberts shot down one of the six MiGs destroyed in the battle. No Sabres were lost. He later shot down a second MiG-15.
Major Roberts resigned from the Air Force in March 1952 and joined North American Aviation as an engineering test pilot. He was involved in testing the F-86H fighter bomber variant of the Sabre, the F-100A Super Sabre, and the F-107A. Roberts was a founding member of the Society of Experimental Test Pilots.
Roberts retired from North American after thirty years.
James O’Connor Roberts, Jr., died at Salinas, California, 6 September 2008, at the age of 84 years.
¹ The Department of Veterans Affairs gives an enlistment date of 17 April 1937.
Major Richard Lowe Johnson, United States Air Force. (Unattributed)Major Richard L. Johnson with the record-setting North American Aviation F-86A Sabre. (Unattributed)
15 September 1948: Major Richard L. Johnson, U.S. Air Force, Air Materiel Command, set a new Fédération Aéronautique Internationale (FAI) World Record Speed Over a 3 Kilometer Course,¹ flying the sixth production North American Aviation F-86A-1-NA Sabre, serial number 47-611, at Muroc Air Force Base, California (renamed Edwards AFB in 1949).
The air temperature was 70° F. (21° C.) with very little wind. Making four consecutive passes at an altitude of 75–125 feet (23 to 38 meters), the Sabre averaged 1,079.84 kilometers per hour (670.98 miles per hour) — 0.889 Mach. The slowest pass was 669.830 miles per hour and the fastest was 672.762 miles per hour (1,077.987 and 1,082.705 kilometers per hour, respectively) — 0.8875–0.8914 Mach.
This was Major Lowe’s second attempt for the speed record. At the National Air Races in Cleveland, Ohio, on 5 September, official timers clocked the wrong airplane, and then on a repeat pass, a timing camera jammed. During that attempt, Major Johnson flew under a light airplane which had wandered onto the course, missing it by about ten feet (3 meters).
Major Richard L. Johnson, USAF with F-86A-1-NA Sabre 47-611 and others at Muroc AFB, 15 September 1948. Note the gun port doors on this early production aircraft. They opened in 1/20 second as the trigger was pressed. Proper adjustment was complex and they were soon eliminated. (Image from F-86 Sabre, by Maurice Allward, Charles Scribner’s Sons, New York, 1978, Chapter 3 at Page 24.)The De la Vaulx Medal.
Major Johnson was awarded the De la Vaulx Medal by the Fédération Aéronautique Internationale.
North American Aviation claimed that any F-86 coming off the assembly line could beat this world record speed. This record stood until 1952 when it was broken by an F-86D Sabre.
The Associated Press reported:
Air Force Tells Of New Speed
NEW YORK — (AP) — The Air Force announced Saturday a new world speed record of 670.981 miles an hour, made with a fully armed standard jet fighter, the North American F-86.
The mark was set Wednesday. It is 20 miles an hour faster than the record set in August, 1947, by a Navy research plane, the Douglas D-558.
It was the first world speed mark in history for a production model aircraft ready to fight.
The pilot was Maj. Richard L. Johnson, slender quiet-spoken test flier for the Air Material Command at Wright-Patterson Airbase near Dayton Ohio. He flew the course at Muroc Lake, Calif., where the record was raised three times last year.
Gen. Hoyt S. Vandenberg, Air Force chief of staff, announced the new mark at Mitchel Field, Long Island, where he participated in one of the numerous shows being held in observance of the first anniversary of the Air Force.
Major Johnson had made a previous speed record attempt flying a different Sabre, but due to a technical problem with the timing equipment, that attempt was disqualified.
F-86A-1-NA 47-605 was the first production Sabre. It first flew on 20 May 1948. (U.S. Air Force)
47-611 was from the first production block of thirty-three F-86A-1-NA Sabres (originally designated P-86A) and was built at North American Aviation’s Inglewood, California, plant. Its NAA serial number was 151-38438. The airplane was withdrawn from service 16 November 1955 and assigned as a ground trainer for the California Air National Guard at Van Nuys, California.
The F-86A was a single-seat, single-engine, swept-wing day fighter, powered by a turbojet engine. The airplane’s design team was headed by Edgar Schmued, who was also responsible for North American’s legendary P-51 Mustang of World War II.
The F-86A had the same dimensions as the prototype XP-86 which had first flown almost two years earlier. The F-86A was 37 feet, 6.6 inches (11.445 meters) long with a wingspan of 37 feet, 1.4 inches (11.313 meters) and overall height of 14 feet, 8.9 inches (4.493 meters). It had an empty weight of 10,093 pounds (4,578 kilograms) and the maximum takeoff weight was 15,876 pounds (7,201 kilograms).
North American Aviation F-86A-1-NA Sabre 47-605, the first production aircraft. (U.S. Air Force)
The F-86 wings’ leading edges were swept to 35° and included leading edge slats, which automatically extended at low speed to provide an increase in lift.
The F-86A was initially powered by a General Electric TG-190A (J47-GE-1) turbojet engine. This was a major improvement over the Chevrolet-built J35-C-3 that had powered the prototype, and it produced almost 25% greater thrust. The J47-GE-1 was rated at 4,850 pounds of thrust (21.57 kilonewtons), or 5,820 pounds (25.89 kilonewtons) with water injection. The J47 was an axial-flow turbojet with a 12-stage compressor, eight combustion chambers, and single-stage turbine. The engine was 12 feet, 0.0 inches (3.658 meters) long, 3 feet, 3.0 inches (0.991 meters) in diameter and weighed 2,475 pounds (1,123 kilograms).
Early in F-86A production, the engine was standardized with the J47-GE-13, which was rated at 5,200 pounds of thrust (23.13 kilonewtons) and 6,000 pounds (26.69 kilonewtons) “wet.” The -13 had the same exterior dimensions as the -1 engine, but weighed 50 pounds (23 kilograms) more.
North American Aviation F-86A-1-NA Sabre 47-630. (North American Aviation, Inc.)
The F-86A had a maximum speed of 679 miles per hour (1,093 kilometers per hour) at Sea Level, and 601 miles per hour (967 kilometers per hour) at 35,000 feet (10,668 meters). The service ceiling as 48,000 feet (14,630 meters) and it could climb to 40,000 feet (12,192 meters) in 10 minutes, 24 seconds. It had a range of 1,200 miles (1,931 kilometers).
This photograph of a Canadair CL-13 Sabre (a license-built F-86E) test-firing its guns shows the firepower of the six .50-caliber machine guns placed close together in the airplane’s nose. The smoke trails show the spin of the bullets caused by the gun barrels’ rifling. The total rate of fire is approximately 7,200 rounds per minute. (Royal Canadian Air Force)
Designed as a day fighter, the F-86 Sabre was armed with six air-cooled Browning AN-M3 .50-caliber aircraft machine guns with 267 rounds of ammunition per gun. These guns had a rate of fire of 1,200 rounds per minute. The F-86A-1-NA had electrically-actuated doors covering the gun ports to maintain the aerodynamically clean surface. Because of their complexity, these doors were deleted beginning with the F-86A-5-NA aircraft.
The fighter could also carry bombs or rockets.
In this photograph, the record-settining North American Aviation F-86A Sabre, 47-611, is seen suspended from a crane while it conducts armament tests. It has just launched a 5-inch High Velocity Aerial Rocket. (U.S. Air Force)
Richard Lowe Johnson ² was born at Cooperstown, North Dakota, 21 September 1917. He was the eighth of nine children of Swedish immigrants, John N. Johnson, a farmer, and Elna Kristina Helgesten Johnson, a seamstress.
Dick Johnson attended Oregon State College at Corvallis, Oregon, as a member of the Class of 1943. He was a member of the Sigma Alpha Epsilon (ΣΑΕ) fraternity.
Dick Johnson was a pitcher for the college baseball team, and later, played for the Boston Red Sox “farm” (minor league) system.
On 18 June 1942, Johnson enlisted as a private in the Air Corps, United States Army. On 5 November, he was appointed an aviation cadet and assigned to flight training.
Aviation Cadet Johnson married Miss Juanita Blanche Carter, 17 April 1943, at Ocala, Florida. The civil ceremony was officiated by Judge D. R. Smith.
After completing flight training, on 1 October 1943, Richard L. Johnson was commissioned as a second lieutenant, Army of the United States (A.U.S.).
Lieutenant Johnson was assigned to the 66th Fighter Squadron, 57th Fighter Group, Twelfth Air Force, in North Africa, Corsica, and Italy, flying the Republic P-47 Thunderbolt. He was promoted to first lieutenant, A.U.S., 9 August 1944, and just over three months later, 26 November 1944, to the rank of captain, A.U.S. On 14 May 1945, Captain Johnson was promoted to the rank of major, A.U.S. (Major Johnson was assigned a permanent rank of first lieutenant, Air Corps, United States Army, on 5 July 1946, with a date of rank retroactive to 21 September 1945.)
Republic P-47D-25-RE Thunderbolt 42-26421, assigned to the 66th Fighter Squadron, 57th Fighter group, Twelfth Air Force. This airplane was purchased by the employees of Republic Aviation. (American Air Museum in Britain UPL 25505)
During World War II, Major Johnson flew 180 combat missions with the 66th Fighter Squadron. He is officially credited with one air-to-air victory, 1 July 1944. Johnson was awarded the Silver Star, the Distinguished Flying Cross with two oak leaf clusters (3 awards), and the Air Medal with twelve oak leaf clusters (thirteen awards).
In 1946, was assigned to the Air Materiel Command Engineering Test Pilot School at the Army Air Forces Technical Base, Dayton, Ohio (Wright-Patterson Air Force Base). He was the second U.S. Air Force pilot to be publicly acknowledged for breaking the “sound barrier.”
A few weeks after arriving at Dayton, Major Johnson met Miss Alvina Conway Huester, the daughter of an officer in the U.S. Navy. Dick Johnson and his wife Juanita were divorced 8 January 1947, and he married Miss Huester in a ceremony in Henry County, Indiana, 10 January 1947. They would have three children, Kristie, Lisa and Richard.
During the Korean War, Major Johnson was sent to the war zone to supervise field installations of improvements to the F-86 Sabre. He was “caught” flying “unauthorized” combat missions and was sent home.
Lieutenant Colonel Johnson resigned from the Air Force in 1953 to become the Chief Test Pilot for the Convair Division of General Dynamics. He made the first flights of the YF-102 on 24 October 1953, the F-106A Delta Dart, 26 December 1956. He made the first flight of the F-111 on 21 December 1964.
Chief Test Pilot Dick Johnson in the cockpit of a Convair B-58A Hustler, a Mach 2 strategic bomber. (Courtesy if Neil Corbett, Test and Research Pilots, Flight Test Engineers)
in 1955, Johnson was one of the six founding members of the Society of Experimental test Pilots.
Dick Johnson was Chief Engineering Test Pilot for the General Dynamics F-111 “Aardvark.” In 1967, the Society of Experimental Test Pilots awarded Johnson its Iven C. Kincheloe Award for his work on the F-111 program. In 1977, Dick Johnson, now the Director of Flight and Quality Assurance at General Dynamics, retired.
In 1998, Dick Johnson was inducted into the Aerospace Walk of Honor at Lancaster, California. His commemorative monument is located in front of the Lancaster Public Library on W. Lancaster Boulevard, just West of Cedar Avenue. ³
Lieutenant Colonel Richard Lowe Johnson, United States Air Force, (Retired), died 9 November 2002 at Fort Worth, Texas. He was buried at Arlington National Cemetery, Arlington, Virginia, on 7 January 2003.
Richard L. Johnson waves from the cockpit of the record-setting North American Aviation F-86A-1-NA Sabre, 47-611.
¹ FAI Record File Number 9866
² Several sources spell Johnson’s middle name as “Loe.”
³ Various Internet sources repeat the statement that “Richard Johnson has been honored with. . . the Thompson Trophy, Mackay Trophy, Flying Tiger Trophy, Federation Aeronautique Internationale Gold Medal and Golden Plate Award of the American Academy of Achievement. . . .” TDiA has checked the lists of awardees of each of the appropriate organizations and has not found any support for the statement.
North American Aviation XFJ-1 Fury. (North American Aviation, Inc.)
11 September 1946:¹ North American Aviation engineering test pilot Wallace Addison (“Wally”) Lien made the first flight of the North American Aviation XFJ-1, Bu. No. 39053. He flew from Mines Field (now, better known as LAX), to Muroc Army Airfield in the high desert of southern California.
Wallace A. Lien
Six months, fifteen days earlier, Lien had made the first flight of the prototype Republic XP-84.)
The XFJ-1 was a turbojet-powered day fighter designed for operation from the United States Navy’s aircraft carriers. It was a single-place, single-engine, low-wing monoplane with retractable tricycle landing gear. The airplane’s wings and tail surfaces were very similar to those of North American’s legendary P-51 Mustang.
Although intended for carriers, the FJ-1 did not have folding wings to reduce its “footprint” when stored on the hangar deck. It did have an interesting feature, though: The nose gear assembly was capable of “kneeling,” putting the airplane in a nose-low, tail-high attitude, allowing Furies to be placed very close together when parked nose-to-tail.
North American Aviation XFJ-1 (North American Aviation, Inc./Curtiss Aldrich Collection, 1000aircraftphotos.com)
The XFJ-1 Fury was 34 feet, 6–3/16 inches (10.520 meters) long, with a wingspan of 38 feet, 2–9/32 inches (11.640 meters), and overall height of 14 feet, 10½ inches (4.534 meters). With the jettisonable wingtip fuel tanks installed, the wingspan was 40 feet, 11-3/8 inches 12.481( meters). The leading edge of each wing was swept aft 3° 40′. The total wing area was 274.88 square feet (25.54 square meters). The wings had an angle of incidence of 1° with 2° 30′ of negative twist. There was 3° dihedral. The horizontal stabilizer had a span of 17 feet, 7 inches (5.539 meters), with an angle of incidence of –1° and 10° dihedral. The vertical fin had 0° offset from the fuselage centerline.
The XFJ-1 had an empty weight of 9,009 pounds (4,086 kilograms) and gross weight of 12,288 pounds (5,574 kilograms).
The XFJ-1 was powered by a prototype General Electric TG-180 (J35-GE-2) axial-flow turbojet engine. The J35-GE-2 used an 11-stage compressor, 8 combustion chambers, and a single-stage turbine. It was rated at 3,750 pounds of thrust (16.68 kilonewtons) at 7,700 r.p.m. The engine was 14 feet, 0 inches (4.267 meters) long, 40 inches (1.016 meters) in diameter, and weighed 2,455 pounds (1,114 kilograms). Production engines were built by Allison (J35-A-5 and -A-7) and by Chevrolet (J35-C-3).
General Electric TG-180 axial-flow turbojet engine. (General Electric)
The production FJ-1 Fury was limited to a maximum speed of 415 knots (478 miles per hour/769 kilometers per hour), and when above 10,000 feet (3,048 meters), to 0.75 Mach. The service ceiling was 32,000 feet (9,754 meters).
The FJ-1 Fury had three self-sealing fuel tanks in the fuselage totaling 465 gallons (1,760 liters). The wingtip tanks had a capacity of 170 gallons (644 liters), each. The total capacity was 805 U.S. gallons (3,047 liters) of JF-1 kerosene.
North American Aviation XFJ-1 with wingtip tanks. (North American Aviation, Inc.)
The XFJ-1 Fury was armed with six air-cooled Browning .50-caliber machine guns, with 250 rounds of ammunition per gun.
North American Aviation built three XFJ-1 prototypes and thirty production FJ-1 Fury fighters. The aircraft underwent a major redesign to become the XP-86 Sabre for the U.S. Air Force, and the FJ-2 Fury for the Navy and Marine Corps.
North American Aviation XFJ-2B Fury prototype Bu. No. 133756 climbs out after takeoff from Los Angeles International Airport, 27 December 1951. (San Diego Air and Space Museum Archive)
Wallace Addison Lien was born 13 August 1915, at Alkabo, North Dakota. He was the second of six children of Olaf Paulson Lien, a Norwegian immigrant and well contractor, and Elma Laura Richardson Lien.
Wallace A. Lien (The 1939 Gopher)
Wally Lien graduated from the University of Minnesota Institute of Technology 17 June 1939 with a Bachelor’s Degree in Mechanical Engineering (B.M.E.). He was a president of the Pi Tau Sigma (ΠΤΣ) fraternity, a member of the university’s cooperative book store board, and a member of the American Society of Mechanical Engineers (A.S.M.E.). He later studied at the California Institute of Technology (CalTech) at Pasadena, California, and earned a master’s degree in aeronautical engineering.
Lien worked as a an engineer at a steel sheet mill in Pennsylvania. He enlisted in the the United States Army at Pittsburgh, Pennsylvania, 18 February 1941. He was accepted as an aviation cadet at Will Rogers Field, Oklahoma City, Oklahoma, 11 November 1941. 26 years old, Lien was 6 feet, 2 inches (1.88 meters) tall and weighed 174 pounds (79 kilograms).
During World War II, Lien remained in the United States, where he served as a test pilot at Wright Field, Dayton, Ohio. He conducted flight tests of the Bell YP-59A Airacomet and the Lockheed XP-80 Shooting Star. Having reached the rank of Major, he left the Air Corps, 16 February 1946. He then went to work for the Republic Aviation Corporation as a test pilot, and North American Aviation.
Wallace Addison Lien married Miss Idella Muir at Elizabeth, New Jersey, 26 December 1946. They would have two sons, Robert and Steven.
Wallace Addison Lien died 28 October 1994 at Colorado Springs, Colorado, at the age of 79 years. He was buried at the Shrine of Remembrance Veterans Honor Court, Colorado Springs, Colorado.
¹ Sources very, with some stating 12 September or 27 November 1946.
North American Aviation F-107A S/N 55-5118 rolling out at Edwards Air Force Base. (U.S. Air Force)Joel Robert Baker (1920–2011). (Photograph courtesy of Neil Corbett)
10 September 1956: North American Aviation test pilot Joel Robert (“Bob”) Baker made the first flight of the F-107A-NA 55-5118, a pre-production tactical fighter bomber, reaching a speed of Mach 1.03. On landing the drogue parachute did not deploy and due to the high speed on rollout, the nose gear strut collapsed, causing minor damage to the new aircraft.
The F-107A was designed as a Mach 2+ fighter bomber capable of carrying nuclear weapons. The plan to carry a Mark 7 bomb in a centerline recess in the aircraft’s belly resulted in the radical appearance of the airplane, with the engine intake mounted above and behind the cockpit.
Based on the F-100 Super Sabre, it was originally designated F-100B, but this was changed to F-107A prior to the first flight.
The North American Aviation F-107A was a single-seat, single-engine supersonic fighter bomber. It was equipped with a very sophisticated stability augmentation system. The F-107A was 61 feet, 10 inches (18.847 meters) long with a wingspan of 36 feet, 7 inches (11.151 meters) and height of 19 feet, 8 inches (5.994 meters). Its empty weight was 22,696 pounds (10.295 kilograms) and had a maximum takeoff weight of 41,537 pounds (18,841 kilograms).
The airplane was powered by a Pratt & Whitney YJ75-P-11 afterburning turbojet which produced a maximum 24,500 pounds of thrust (108.98 kilonewtons).
This gave the F-107A a maximum speed of 890 miles per hour (1,432 kilometers per hour) at Sea Level, and 1,295 miles per hour (2,084 kilometers per hour) at 36,000 feet (10,973 meters). It could climb at an initial rate of 39,900 feet per minute (202.7 meters per second) and had a service ceiling of 53,200 feet (16,215 meters).
North American Aviation F-107A 55-5118 in flight. (U.S. Air Force)
The Mark 7 was a variable-yield fission bomb that could be pre-set to detonate with ranges between 8 and 61 kilotons. It weighed approximately 1,700 pounds (771 kilograms).
The second F-107A, 55-5119, was the weapons test aircraft and was armed with four 20mm M39 cannon with 200 rounds per gun.
The F-107A was in competition with Republic’s F-105 Thunderchief, which was selected by the Air Force for production. Only three F-107A test aircraft were built.
After Air Force testing, two F-107s, 55-5118 and 55-5120, were turned over to the NACA High-Speed Flight Station for use as research aircraft. John Barron (“Jack”) McKay was assigned as the project pilot. 55-5118 made only 4 flights for NACA before being grounded. 55-5120 made 42 flights.
Today, 55-5118 is at the Pima Air and Space Museum, Tucson, Arizona. Its sister ship, 55-5119, is at the National Museum of the United States Air Force, Wright-Patterson AFB, Ohio. The third airplane, 55-5120, was damaged on takeoff with test pilot Scott Crossfield in the cockpit, 1 September 1959. It was not repaired.
The second F-107A, 55-5119, turns from downwind to base leg for landing on Runway 4, Edwards Air Force Base. This was the only one of the three prototypes to be equipped with 20 mm M39 cannon.(U.S. Air Force)The first XF-107, 118 arrives at HSFS, 6 November 1957. (NASA E-57-3192)
North American Aviation NA-73X prototype, NX19998, at Mines Field, California, 9 September 1940. (North American Aviation, Inc.)
9 September 1940: North American Aviation completed assembly of the NA-73X, the first prototype of the new Mustang Mk.I fighter for the Royal Air Force. This was just 117 days after the British Purchasing Commission had authorized the construction of the prototype. The airplane was designed by a team led by Edgar Schmued. The 1,150-horsepower Allison V-12 engine had not yet arrived, so the NA-73X was photographed with dummy exhaust stacks. The prototype’s company serial number was 73-3097. It had been assigned a civil experimental registration number, NX19998.
The NA-73X 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 Mustang was the first airplane to use a laminar-flow wing. The fuselage panels were precisely designed and very smooth. Flush riveting was used. 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, 2⅝ 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).
Aeronautical Engineer Edgar Schmued with a North American P-51-2-NA (Mustang Mk.IA), 41-37322. (San Diego Air and Space Museum Archives)
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 four valves per cylinder and a compression ratio of 6.65:1. It used 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 7 feet, 4.38 inches (2.245 meters) long, 3 feet, 0.64 inches (0.931 meters) high, and 2 feet, 5.29 inches (0.744 meters) wide. It had a dry weight of 1,310 pounds (594 kilograms).
U.S. Army Air Corps flight tests of the fully-armed production Mustang Mk.I (XP-51 41-038), equipped with the V-1710-39 and a 10 foot, 9-inch (3.277 meters) diameter Curtiss Electric propeller, resulted in a maximum speed of 382.0 miles per hour (614.8 kilometers per hour) at 13,000 feet (3,962 meters). The service ceiling was 30,800 feet (9,388 meters) and the absolute ceiling was 31,900 feet (9,723 meters).
The Curtiss P-40D Warhawk used the same Allison V-1710-39 engine as the XP-51, as well as a three-bladed Curtiss Electric propeller. During performance testing at Wright Field, a P-40D, Air Corps serial number 40-362, weighing 7,740 pounds (3,511 kilograms), reached a maximum speed of 354 miles per hour (570 kilometers per hour) at 15,175 feet (4,625 meters). Although the Mustang’s test weight was 194 pounds (88 kilograms) heavier, at 7,934 pounds (3,599 kilograms), the Mustang was 28 miles per hour (45 kilometers per hour) faster than the Warhawk. This demonstrates the effectiveness of the Mustang’s exceptionally clean design.
Only one NA-73X was built. It made its first flight 26 October 1940 with test pilot Vance Breese. The prototype suffered significant damage when it overturned during a forced landing, 20 November 1941. NX19998 was repaired and flight testing resumed. The prototype’s final disposition is not known.
Originally ordered by Great Britain, the Mustang became the legendary U.S. Army Air Corps P-51 Mustang. A total of 15,486 Mustangs were built by North American Aviation at Inglewood, California and Dallas, Texas. Another 200 were built in Australia by the Commonwealth Aircraft Corporation.
The P-51 remained in service with the U.S. Air Force until 27 January 1957 when the last one, F-51D-30-NA 44-74936, was retired from the 167th Fighter Squadron, West Virginia Air National Guard. It was then transferred to the National Museum of the United States Air Force at Wright-Patterson Air Force Base, where it is on display.
North American Aviation NA-73X prototype, NX19998, left front quarter view. (North American Aviation, Inc.)
