20 May 1948

Aviation, , , , ,
North American Aviation P-86A-1-NA Sabre 47-605, the first production aircraft. (U.S. Air Force)

20 May 1948: The first production North American Aviation, Inc., P-86A-1-NA, 47-605, made its first flight.

The P-86A-1-NA was very similar to the three XP-86 prototypes. As an operational fighter, its empty weight increased 347 pounds to 10,077 pounds. The Chevrolet J35-C-3 and Allison J35-A-5 engines were replaced with a more powerful General Electric J47-GE-1. The fighter’s maximum speed increased 74 miles per hour to 673 miles per hour at Sea Level.

The P-86 was unlike any airplane before it. (The designation was changed to F-86 the following month.) It was the first airplane produced with a swept wing. After analyzing World War II test data for the Messerschmitt Me 262, North American’s engineers designed a wing with a 35° degree sweepback to its leading edge. The wing sweep allowed high speed shock waves to form without stalling the entire wing. The wing tapered toward the tips, and its thickness also decreased from the root to the tip. In order to create a very strong but very thin wing, it was built with a two-layered aluminum skin, instead of ribs and spars, with each layer separated by “hat” sections. The thickness of the skin panels also tapered to decrease weight.

Cutaway illustration XP-86 concept. The side speed brakes were altered in production and the ventral brake eliminated. (North American Aviation, Inc.)

The wing  incorporated leading edge “slats” which were airfoil sections that automatically extended below 290 knots, smoothing the air flow over the wing’s upper surface and creating more lift at slow speeds. Above that speed, aerodynamic forces closed the slats, decreasing drag and allowing for higher speeds. Effectively, the wing could change its shape in flight.

Like the XP-86, the P-86A was 37 feet, 6.5 inches (11.443 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). The empty weight was 10,077 pounds (4,571 kilograms), gross weight, 14,050 pounds (6,373 kilograms) and maximum takeoff weight was 15,876 pounds (7,201 kilograms).

The J47-GE-1 was an axial-flow turbojet with a 12-stage compressor, 8 combustion chambers, and single stage turbine. It had a normal power rating of 4,320 pounds of thrust (19.216 kilonewtons) at 7,370 r.p.m.; and military power, 5,200 pounds (23.131 kilonewtons) at 7,950 r.p.m. (30-minute limit).

The P-86A had an initial rate of climb 7,470 feet per minute (37.95 meters per second) and could reach 40,000 feet (12,192 meters) in 10 minutes, 24 seconds. Its service ceiling was 48,000 feet (14,630 meters).

North American Aviation F-86A-5-NA 48-273. 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. (U. S. Air Force)

The Sabre was armed with six Browning AN-M3 .50-caliber aircraft machine guns placed in the nose, with three on either side of the engine intake. These were lighter and had a higher rate of fire than the World War II AN-M2 machine guns. Ammunition containers had a capacity of 300 rounds, but normally they carried 267 rounds per gun. Early aircraft had small doors covering each gun port. They opened in 0.05 seconds but were difficult to keep properly adjusted, so they were soon deleted.

The airplane could also be armed with two bombs and up to sixteen 5-inch (12.7 centimeter) High Velocity Aerial Rockets (HVAR) on underwing hardpoints.

North American Aviation built thirty-three P-86A-1-NAs. The U.S. Air Force ordered 190 F-86Bs, but these were cancelled in favor of the F-86A-5-NA.

The F-86A became operational with the 1st Fighter Group at March Air Force Base, near Riverside, California. In February 1949, a contest was held within the group to select a name for the new fighter. “Sabre” was chosen.

47-605 was the first production P-86A-1-NA Sabre. (U.S. Air Force)

© 2019, Bryan R. Swopes

20 May 1941

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NAA test pilot Robert C. Chilton stand on the wing of P-51B-10-NA 42-106435. (North American Aviation, Inc.)
North American Aviation test pilot Robert C. Chilton standing on the wing of P-51B-10-NA Mustang 42-106435. (North American Aviation, Inc.)

20 May 1941: North American Aviation, Inc., test pilot Robert Creed Chilton took the first XP-51 for its maiden flight at Mines Field, Los Angeles, California. The XP-51 was the fourth production Mustang Mk.I built for the Royal Air Force, AG348 (North American serial number 73-3101).

The Mustang was reassigned to the U.S. Army Air Force, designated as XP-51, serial number 41-038, and sent to Wright Field, Dayton, Ohio, for evaluation.

North American Aviation Mustang Mk.I AG348 at Mines Field, California, 1941. North American Aviation, Inc., photograph 73-0-9. (Ray Wagner Collection/SDASM)
North American Aviation Mustang Mk.I AG348, Mines Field, California, 1941. North American Aviation, Inc., photograph 73-0-10. (Ray Wagner Collection/SDASM)
North American Aviation Mustang Mk.I AG348 at Mines Field, California, 1941. North American Aviation, Inc., photograph. (Ray Wagner Collection/SDASM)

Later, the XP-51 was extensively tested by the National Advisory Committee for Aeronautics (N.A.C.A.) at the Langley Memorial Aeronautical Laboratory, Langley Field, Hampton, Virginia.

Today, the restored XP-51 is in the collection of the E.A.A. AirVenture Museum at Oshkosh, Wisconsin.

North American Aviation XP-51 41-038 at the NACA Langley Memorial Aeronautical Laboratory. (NASA LMAL 27030)
North American Aviation XP-51 41-038 at the NACA Langley Memorial Aeronautical Laboratory. (NASA)

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 XP-51 41-039 at NACA Langley. (NASA)
North American Aviation XP-51 41-039 at NACA Langley. Note the increased length of the carburetor intake. (NASA)

The Mustang 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 with a compression ratio of 6.65:1. The -F3R had a Normal Power rating of 880 horsepower at 2,600 r.p.m., at Sea Level, and 1,000 horsepower at 2,600 r.p.m. at 11,000 feet (3,353 meters). It had a Takeoff and Military Power rating of 1,150 horsepower at 3,000 r.p.m., to 11,800 feet (3,597 meters). The engine 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 V-1710-F3R was 7 feet, 4.38 inches (2.245 meters) long, 3 feet, 0.54 inches (0.928 meters) high, and 2 feet, 5.29 (0.744 meters) wide. It weighed 1,310 pounds (594 kilograms).

The Mustang Mk.I had a maximum speed of 382 miles per hour (615 kilometers per hour) at 13,700 feet (4,176 meters), the Allison’s critical altitude, 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 XP-51 41-038 at NACA Langley Memorial Aeronautical Laboratory, right profile. (NASA LAML)
North American Aviation XP-51 41-038 at NACA Langley Memorial Aeronautical Laboratory, right profile. (NASA)

The Mustang Mk.I was armed with four air-cooled Browning .303 Mk.II aircraft 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.

North American Aviation XP-51 41-038 at NACA Langley Memorial Aeronautical Laboroatory. (NASA LAML 27045)
North American Aviation XP-51 41-038 at NACA Langley Memorial Aeronautical Laboratory, right three-quarter view. (NASA)

The Mk.I was 30 m.p.h. faster than its contemporary, the Curtiss P-40 Warhawk, though both used the same engine. Below 15,000 feet, the Mustang was also 30–35 m.p.h faster than a Supermarine Spitfire, which had a more powerful Roll-Royce Merlin V-12.

The XP-51 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.

North American Aviation XP-51 41-038 at NACA Langley Memorial Aeronautical Laboratory, rear view. (NASA LMAL 27033)
North American Aviation XP-51 41-038 at NACA Langley Memorial Aeronautical Laboratory, rear view. (NASA)

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 Republic 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.

North American Aviation XP-51 at Wright Field. (Charles M. Daniels Collection, San Diego Air & Space Museum Archives, Catalog #: 15_002838)

© 2018, Bryan R. Swopes

Amelia Earhart’s Lockheed Electra 10E Special, NR16020

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Amelia Earhart's Lockheed Electra 10E Special, NR16020, 1937. (Photograph by F.X. O'Grady, Cleveland State University, Michael Schwartz Library, Division of Special Collections)
Amelia Earhart’s Lockheed Electra 10E Special, NR16020, 1937. (Photograph by F.X. O’Grady, Cleveland State University, Michael Schwartz Library, Division of Special Collections)
Amelia Earhart’s Lockheed Model 10E Electra, NR16020. (San Diego Air & Space Museum, Catalog #: 01_00091572)

For her around-the-world flight, the airplane that Amelia Earhart chose was a Lockheed Electra 10E, manufactured by the Lockheed Aircraft Company, Burbank, California. The Electra Model 10 was an all-metal, twin-engine, low-wing monoplane with retractable landing gear, designed as a small, medium-range airliner. In the standard configuration it carried a crew of 2 and up to 10 passengers. The Model 10 was produced in five variants with a total of 149 airplanes built between August 1934 and July 1941. Lockheed built fifteen Model 10Es. Earhart’s was serial number 1055.

Amelia Earhart stands in the cockpit of her unfinished Lockheed Electra 10E Special, serial number 1055, at the Lockheed Aircraft Company factory, Burbank, California, 1936. (Purdue University Libraries, Archives and Special Collections)
Amelia Earhart stands in the cockpit of her unfinished Lockheed Electra 10E Special, serial number 1055, at the Lockheed Aircraft Company, Burbank, California, 1936. (Purdue University Libraries, Archives and Special Collections)

$80,000 to buy the Electra was provided by the Purdue Research Foundation from donations made by several individuals. George Palmer Putnam, Amelia’s husband, made the arrangements to order the airplane and in March 1936 gave Lockheed the authorization to proceed, with delivery requested in June. The modifications included four auxiliary fuel tanks in the passenger compartment, a navigator’s station to the rear of that, elimination of passenger windows, installation of a Sperry autopilot and various radio and navigation equipment and additional batteries. The Electra was not ready until mid-July.

Lockheed Electra 10E NR16020
Lockheed Electra 10E NR16020. (Purdue University Libraries, Archives and Special Collections)

Amelia Earhart test flew the new airplane at Burbank on 21 July with Lockheed test pilot Elmer C. McLeod. She accepted the Electra on her 39th birthday, 24 July 1936. It received civil certification NR16020. (The letter “R” indicates that because of modifications from the standard configuration, the airplane was restricted to carrying only members of the flight crew, although Earhart and her advisor, Paul Mantz, frequently violated this restriction.)

Lockheed technicians check the Electra's fuel capacity with the airplane in normal flight attitude. (Purdue)
Lockheed technicians checking the Electra with the airplane in a normal flight attitude. (Purdue University Libraries, Archives and Special Collections)

The Electra 10E was 38 feet, 7 inches (11.760 meters) long with a wingspan of 55 feet (16.764 meters) and overall height of 10 feet, 1 inch (3.074 meters). The standard Model 10 had an empty weight of 6,454 pounds (2,927.5 kilograms) and a gross weight of 10,500 pounds (4,762.7 kilograms). NR16020 had an empty weight of 7,265 pounds (3295.4 kilograms). Lockheed’s performance data was calculated using 16,500 pounds (7,484.3 kilograms) as the Maximum Takeoff Weight.

Amelia Earhart’s Lockheed Electra 10E Special, NR16020, photographed at Oakland Municipal Airport, 14 March 1937. Note the large navigator’s window in the aft fuselage. This would be replaced by sheet aluminum at Miami.  (William T. Larkins)
Amelia Earhart’s Lockheed Model 10E Electra, NR16020, just prior to departure, Miami, Florida, 1 June 1937. Note that the Electra’s rear window has been replaced by aluminum sheet. (Miami Herald)

NR16020 had a total fuel capacity of 1,151 gallons (4,357 liters) in ten tanks in the wings and fuselage. 80 gallons (302.8 liters) of lubricating oil for the engines was carried in four tanks.

Amelia Earhart poses with her Electra's Pratt and Whitney R-1340-S3H1 Wasp radial engine and two-bladed Hamilton Standard variable-pitch, constant-speed propeller.
Amelia Earhart poses with one of her Electra’s Pratt & Whitney Wasp S3H1 radial engines and its two-bladed Hamilton Standard 12D-40 variable-pitch, constant-speed propeller. (AP)

Earhart’s Electra 10E Special was powered by two air-cooled, supercharged, 1,343.804-cubic-inch-displacement (22.021 liter) Pratt & Whitney Wasp S3H1 nine-cylinder radial engines, with a compression ratio of 6:1. These engines used a single-stage centrifugal supercharger and were rated at 550 horsepower at 2,200 r.p.m. at 5,000 feet (1,524 meters) and 600 horsepower at 2,250 r.p.m. for take off. The direct-drive engines turned 9 foot, 7/8-inch (3.010 meters) diameter, two-bladed, Hamilton Standard variable-pitch, constant-speed propellers. The Wasp S3H1 is 4 feet, 3.60 inches (1.311 meters) in diameter and 3 feet, 7.01 inches (1.093 meters) long. It weighed 865 pounds (392 kilograms).

Ameila Earhart with her Electra 10E, NR16020, at Lockheed Aircraft Company, Burbank, California, December 1936. Earhart’s automobile is a light blue 1936 Cord 810 convertible. (The Autry National Center Museum, Automobile Club of Southern California Archives)
Amelia Earhart with her Electra 10E, NR16020, at Lockheed Aircraft Company, Burbank, California, December 1936. Earhart’s automobile is a tan 1936 Cord 812 Phaeton, powered by a liquid-cooled, normally-aspirated 289-cubic-inch (4.7 liters) Lycoming FB V-8 engine, rated at 117 horsepower at 3,600 r.p.m. (The Autry National Center Museum, Automobile Club of Southern California Archives)

A detailed engineering report was prepared by a young Lockheed engineer named Clarence L. (“Kelly”) Johnson to provide data for the best takeoff, climb and cruise performance with the very heavily loaded airplane. The maximum speed for the Model 10E Special at Sea Level and maximum takeoff weight was 177 miles per hour (284.9 kilometers per hour), a reduction of 25 miles per hour (40.2 kilometers per hour) over the standard airplane. The maximum range was calculated to be 4,500 miles (7,242.1 kilometers) using 1,200 gallons (4,542.5 liters) of fuel.

Clarence L. "KellY" Johnson conducted wind tunnel testing of the Model 10 at the University of Michigan.
Clarence L. “Kelly” Johnson conducted wind tunnel testing of the Model 10 at the University of Michigan. (Lockheed Martin)

Johnson would later design many of Lockheed’s most famous aircraft, such as the SR-71A Blackbird Mach 3+ strategic reconnaissance airplane. As a student at the University of Michigan, he worked on the wind tunnel testing of the Lockheed Electra Model 10 and made recommendations that were incorporated into the production airplane.

Amelia Earhart's Lockheed Electra 10E Special NR16020 after it crashed on takeoff from NAS Ford Island, 0553, 20 March 1937.
Amelia Earhart’s Lockheed Electra 10E Special NR16020 after it crashed on takeoff at Luke Field (NAS Ford Island), 0553, 20 March 1937. The preliminary estimate to repair the airplane was $30,000. (Hawaii’s Aviation History)
Amelia Earhart's heavily damaged Lockheed Electra 10E Special, NR16020, after a ground loop on takeoff at Luke Field, Hawaii, 20 March 1937. (Amelia Earhart stands in the cockpit of her unfinished Lockheed Electra 10E Special, serial number 1055, at the Lockheed Aircraft Company factory, Burbank, California, 1936. (Purdue University Libraries, Archives and Special Collections)
Amelia Earhart’s heavily damaged Lockheed Electra 10E Special, NR16020, after a ground loop on takeoff at Luke Field, Hawaii, 20 March 1937. The damaged propellers and engine cowlings have already been removed. The fuselage fuel tanks are being emptied. (Purdue University Libraries, Archives and Special Collections) 

The Electra was heavily damaged when it crashed on takeoff at Luke Field (NAS Ford Island), Honolulu, Hawaii, on the morning of 20 March 1937. It was shipped back to Lockheed for extensive repairs. An investigating board of U.S. Army officers did not report a specific cause for the accident, but there was no evidence of a “blown tire” as had been reported in the newspapers. The repairs were completed by Lockheed and the aircraft certified as airworthy by a Bureau of Commerce inspector, 19 May 1937. The airplane had flown 181 hours, 17 minutes since it was built.

Lockheed engineers use X-ray equipment to scan for hidden damage while the Electra undergoes repairs at Lockheed Aircraft Company, Burbank, California, May 1937.
Lockheed engineers Tom Triplett (left) and Victor Barton use X-ray equipment to scan for hidden damage while the Electra undergoes repairs at Lockheed Aircraft Company, Burbank, California, 3 May 1937. (AP File Photo/Schlesinger Library, Radcliffe College)
Amelia Earhart in teh cockpit of her Lockheed Electra 10E NR16020.(AFP/Getty Images)
Amelia Earhart in the cockpit of her Lockheed Electra 10E NR16020. The Sperry GyroPilot is at the center of the instrument panel. (AFP/Getty Images)
Amelia Earhart stands behind the additional fuel tanks installed in the aft cabin of her Electra. (AP)
Photographed from the rear of the plane, Amelia Earhart leans over the fuel tanks that have been installed in the aft cabin of her Electra. (AP)  

Earhart’s Electra was equipped with a Western Electric Model 13C radio transmitter and Model 20B receiver for radio communication. It used a Sperry GyroPilot gyroscopic automatic pilot.

© 2018, Bryan R. Swopes

20 May 1937

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Amelia Earhart with her Lockheed Electra 10E, NR16020.

Leg 1: After her Lockheed Electra 10E Special, NR16020, was repaired by Lockheed following a takeoff accident at Wheeler Field, Oahu, in March, Amelia Earhart repositioned it to Oakland Municipal Airport to begin her second attempt to fly around the world. Because of changing weather patterns since the earlier attempt, this time her route will be eastward.

Great Circle route between Oakland Airport and Union Air Terminal. (Great Circle Mapper)

On 20 May 1937, without any public notice, Earhart and her navigator, Captain Frederick J. Noonan, left Oakland, California, on the first leg of the trip: 283 nautical miles (325 miles (523 kilometers) to Union Air Terminal, Burbank, California (now, Hollywood Burbank Airport—BUR), where the airplane was manufactured and repaired. They arrived at about 6:00 p.m. and remained there over night.

“The rebuilt Electra came out of the Lockheed plant on May 19. Two days later we flew it to Oakland. . .  As that time we had made no announcement of my decision to reverse the direction of the flight. It seemed sensible to slip away as quietly as we could. While I was actually heading for Miami, with hope of keeping on from there eastward, technically the journey from Burbank across the country was a shake-down flight. If difficulties developed we would bring the ship back to the Lockheed plant for further adjustments.”

—Amelia Earhart

Amelia Earhart in the cockpit of her Electra. (Rudy Arnold Collection)

© 2018, Bryan R. Swopes

20–21 May 1932

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Amelia Earhart at Harbor Grace, Newfoundland, 20 May 1932. Photographer: Ernest Maunder. Courtesy of Library and Archives Canada (PA-057854).
Amelia Earhart at Harbor Grace, Newfoundland, 20 May 1932. Photographer: Ernest Maunder. Courtesy of Library and Archives Canada (PA-057854).

20 May 1932: At 7:12 p.m., local, aviatrix Amelia Earhart departed Harbor Grace, Newfoundland, on a solo transoceanic flight. Her airplane was a modified single-engine Lockheed Model 5B Vega, registration NR7952.

Her plan was to fly all the way to Paris, but after her altimeter had failed, encountering adverse weather, including heavy icing and fog, a fuel leak, and a damaged exhaust manifold, Earhart landed in a field at Culmore, Northern Ireland. The distance flown was 2,026 miles (3,260.5 kilometers). Her elapsed time was 14 hours, 56 minutes.

A lone, astonished farmer saw her land.

Amelia cut the switches, climbed out of the plane, and, as the man approached the plane, called out, “Where am I?”

Danny McCallion replied obligingly and with excruciating accuracy. “In Gallegher’s pasture.”

—The Sound of Wings by Mary S. Lovell, St. Martin’s Press, New York, 1989, Chapter Fifteen at Page 183.

Amelia Earhart with her Lockheed Vega 5B, NR7952, at Culmore, North Ireland after her solo transatlantic flight, 21 May 1932. (National Library of Ireland)

Though she didn’t make it all the way to Paris, she was the first woman—and only the second person, after Charles A. Lindbergh—to fly solo across the Atlantic Ocean. Lindbergh’s flight was on the same date, five years earlier.

Great Circle route between Harbour Grace Airport, Newfoundland, and Londonderry Airport, near Culmore, Northern Ireland. 1,754 nautical miles (2,019 statute miles/3,249 kilometers). (Great Circle Mapper)

In an unusual move, Amelia Earhart, a civilian, was awarded the United States military’s Distinguished Flying Cross by Patrick J. Hurley, Secretary of War, 18 July 1932.

Amelia Earhart’s Distinguished Flying Cross certificate signed by Patrick J. Hurley, Secretary of War.

Built by the Lockheed Aircraft Company in December 1928, the Vega is a single-engine high-wing monoplane designed to carry a pilot and up to seven passengers. The fuselage was molded laminated plywood monocoque construction and the wing was cantilevered wood. The Vega 5B is 27 feet, 6 inches (8.382 meters) long with a wingspan of 41 feet (12.497 meters) and overall height of 8 feet, 2 inches (2.489 meters).

Amelia Earhart stands in front of her Lockheed Model 5B Vega, NR7952, at Union Airport, 1932. Left to right, Earhart; Lockheed founder Allan Loughead; Paul Mantz; and Lockheed president Lloyd Stearman. (Philip S. Dockter/Valley Relics Museum)

Earhart’s Vega, serial number 22, was certified by the Department of Commerce, 17 September 1931, with its empty weight increased 220 pounds (99.8 kilograms) to 2,695 pounds (1,222.4 kilograms) and maximum gross weight of 4,375 pounds (1984.5 kilograms).

Aircraft Registration Certificate, Lockheed Vega, serial number 22, NC7952, 1928.

NR7952 was modified at the Fokker Aircraft Corporation of America factory in Teterboro, New Jersey, to increase the fuel capacity to 420 gallons (1,589.9 liters). While it was there, Earhart’s mechanic, Eddie Gorski, replaced the original Pratt & Whitney Wasp B engine with a new Wasp C, an air-cooled, supercharged 1,343.804-cubic-inch-displacement (22.021 liter) nine cylinder radial engine with a compression ration of 5.25:1. The Wasp C was rated at 420 horsepower at 2,000 r.p.m. at Sea Level, burning 58 octane gasoline.¹ It was a direct-drive engine, and turned a two-bladed Hamilton Standard controllable-pitch propeller. The Wasp C was 3 feet, 6.63 inches (1.083 meters) long, 4 feet, 3.44 inches (1.307 meters) in diameter and weighed 745 pounds (338 kilograms).

The standard Vega 5 had a cruising speed of 165 miles per hour (265.5 kilometers per hour) and maximum speed of 185 miles per hour (297.7 kilometers per hour). The service ceiling was 15,000 feet (4,572 meters). Range with standard fuel tanks was 725 miles (1,166.8 kilometers).

Amelia Earhart disappeared in 1937 while attempting to fly around the world. Her Lockheed Model 5B Vega, NR7952, is in the collection of the Smithsonian Institution National Air and Space Museum.

Amelia Earhart's Lockheed Vega 5b, NR7952, at the Smithsonian Institution National Air and Space Museum.
Amelia Earhart’s Lockheed Model 5B Vega, NR7952, at the Smithsonian Institution National Air and Space Museum. (NASM)

¹ The Pratt & Whitney Wasp C was also used by the U.S. Army and Navy, designated R-1340-7. It was rated at 450 horsepower at 2,100 r.p.m. at Sea Level.

© 2019, Bryan R. Swopes