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, 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. (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 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 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).
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. (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 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. 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 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 the cockpit of her Lockheed Electra 10E NR16020. The Sperry GyroPilot is at the center of the instrument panel. (AFP/Getty Images)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.
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)
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 Wingsby 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 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.
On 25 February 1927, Charles A. Lindbergh, backed by a group of St. Louis, Missouri, businessmen, contracted the Ryan Airlines Company to build an airplane for the purpose of flying across the Atlantic Ocean from New York to Paris. The agreed price was $10,580. 63 days later, 28 April, Lindbergh made the first flight of the Ryan NYP at Dutch Flats, a short distance from the factory on Juniper Street.
Ryan airplane factory at the foot of Juniper Street, San Diego, California. (Donald A. Hall Photograph & Document Collection)
The Ryan NYP is a single-place, single-engine, strut-braced high-wing monoplane with fixed landing gear and tail skid, built at the Ryan Airlines Company factory, San Diego, California. Although it was based on the earlier Ryan M-2, Spirit of St. Louis was a complete redesign, with longer wings and fuselage. The ailerons are smaller. The airplane has no serial number and was not issued a type certificate by the Civil Aeronautics Authority. It was assigned an experimental registration number, NX211.
Spirit of St. Louis is 27 feet, 8 inches (8.433 meters) long with a wingspan of 46 feet, 0 inches (14.021 meters) and height of 9 feet, 10 inches (2.997 meters). The wing has a chord of 7 feet, 0 inches (2.134 meters) and area of 319 square feet (29.636 square meters). There is no dihedral or sweep. The airfoil is the Clark Y, with a cambered upper surface, while the lower surface is flat from aft of the wing’s forward spar.
The fuselage and tail surfaces are constructed of welded tubular SAE 1020 steel framework covered with doped linen fabric. The wing was built as a single unit with wooden spars and ribs. The leading edge is covered in plywood and the entire wing with doped fabric. The rib spacing is 11 inches (27.94 centimeters). The horizontal stabilizer is adjustable from the cockpit to control trim as the fuel load decreased.
Welded SAE 1020 tubular steel framework fuselage of the Spirit of St. Louis. (Donald A. Hall Photograph & Document Collection)This photograph shows the complex wooden structure of the wing and welded tubular framework of the fuselage of Spirit of St. Louis. The 310 gallon (1,174.5 liter) main fuel tank is in place. The flat lower surface of the wing is the primary characteristic of the Clark Y airfoil. (Donald A. Hall Photograph & Document Collection)
The split-axle main landing gear uses bungee cords for shock absorption. B.F. Goodrich pneumatic tires are mounted on 21 inch × 4 inch (533 millimeter × 102 millimeter) wire-spoked wheels. The struts were designed for a load factor of 4 and allow 6½ inches (165 millimeters) of vertical motion. The wheels can spread to absorb impacts. The tail skid is heat-treated chrome moly tubing.
This photograph shows the forward 86 gallon (325.6 liter) fuel tank and 25 gallon (94.6 liter) lubricating oil tank in the nose of Spirit of St. Louis. The Wright J-5C Whirlwind radial engine has been installed. The bungee cord suspension of the main landing gear is also visible. (Donald A. Hall Photograph & Document Collection)
The main fuel tank and lubricating oil tank were placed in front of the cockpit for safety reasons, but this eliminated any forward view for the pilot. A small retractable periscope with a 3 inch × 5 inch (76 × 127 millimeters) viewing area in the instrument panel could be extended through the left side of the fuselage.
Spirit of St. Louis was powered by an air-cooled, normally-aspirated 787.26-cubic-inch-displacement (12.901 liter) Wright Aeronautical Corporation Model J-5C Whirlwind nine-cylinder radial engine, serial number 7331. This was a direct-drive engine with a compression ratio of 5.1:1. The engine was assembled by Thomas W. Rutledge at the Wright factory in Paterson, New Jersey, and was completed 1 April 1927.
Charles Lindbergh works on the Wright Model J-5C Whirlwind installed on the Spirit of St. Louis. (Library of Congress)
The J-5 was built with a cylindrical cast aluminum crankcase and steel cylinder barrels with integral cooling fins. The cylinder head was cast aluminum with a hemispherical combustion chamber, which allowed larger valves and improved combustion efficiency. There were two valves per cylinder, actuated by pushrods and rocker arms.
The Wright J-5C was rated at 200 horsepower at 1,800 r.p.m., and 220 horsepower at 2,000 r.p.m. The engine was 2 feet, 10 inches (0.864 meters) long and 3 feet, 9 inches (1.143 meters) in diameter. It weighed 508 pounds (230.4 kilograms).
During 50-hour endurance tests, the J-5C produced 216 horsepower at 1,837 r.p.m., and 238 horsepower at 1,970 r.p.m. It averaged 223 horsepower during a 100-hour, full-throttle test conducted by the U.S. Navy in May 1927. An overload test run with an external supercharger produced 295 horsepower at 2,150 r.p.m. for 50 hours.
The engine drove a two-bladed Standard Steel Propeller Co. adjustable-pitch propeller with a diameter of 8 feet, 9 inches (2.667 meters). The drop-forged solid Duralumin blades attached to a steel hub. The pitch of the propeller blades could be set prior to flight. Spirit of St. Louis‘ blades were set to 16¼ inches (41.275 centimeters). (This is the distance that the propeller would travel forward during one revolution.)
Instrument panel and fuel manifold. (Donald A. Hall Photograph & Document Collection)
The airplane’s Instrument panel included a Waltham Watch Company Eight-Day Clock and a Pioneer Instrument Company Earth Inductor Compass.
A barograph was carried on board to certify the non-stop flight for the Fédération Aéronautique Internationale.
Ryan NYP N-X-211, Spirit of St. Louis, front view, at Dutch Flats, San Diego, California, 28 April 1927. (Donald A. Hall Photograph & Document Collection)
During flight testing at San Diego, the maximum speed of Spirit of St. Louis was found to be 120.0 miles per hour (193.1 kilometers per hour) at full load, increasing to 124.5 miles per hour (200.4 kilometers per hour) when lightly loaded. It reached 129 miles per hour (207.6 kilometers per hour) over a 3-kilometer course, when the fuel load was just 25 gallons (95 liters). The Ryan’s best economic speed was 97 miles per hour (156.1 kilometers per hour) at full load, and 67 miles per hour (107.8 kilometers per hour), light. Under ideal conditions, the airplane had a maximum range of 4,110 miles (6,614 kilometers).
The Ryan NYP N-X-211, Spirit of St. Louis, right front quarter view, at Dutch Flats, San Diego, California. (Donald A. Hall Photograph & Document Collection)Ryan NYP N-X-211, Spirit of St. Louis, right side view, at Dutch Flats, San Diego, California, 28 April 1927. (Donald A. Hall Photograph & Document Collection)
Spirit if St. Louis has an empty weight of 2,150 pounds (975 kilograms). When in departed San Diego on 10 May 1927, it was overloaded with an additional 25 gallons (94.6 liters) of gasoline, bringing the total gross weight at takeoff to 5,250 pounds (2,381 kilograms). (The density of California gasoline was 6.12 pounds per gallon/0.73 kilograms per litre.)
Donald A. Hall, designer of the Ryan NYP, Spirit of St. Louis, at work in his office at the Ryan Airlines, Inc., factory, San Diego, CA, 1927. (Donald A Hall Collection)
Designer Donald A. Hall estimated that the Ryan NYP required 850 engineering man hours and 3,000 construction man hours.
Spirit of St. Louis made 174 flights, with a total duration of 489 hours, 28 minutes. NX211 last made its final flight 30 April 1928, from St. Louis, Missouri, to Bolling Field, Washington, D.C., where Charles A. Lindbergh presented it to the Smithsonian Institution. Its registration was cancelled 2 June 1928.
The Ryan NYP Spirit of St. Louis, NX211, on display at the Smithsonian Institution National Air and Space Museum (NASM)
Charles A. Lindbergh and the Spirit of St. Louis. (Hulton Archive/Getty Images)
20 May 1927, 7:51:30 a.m. Eastern Daylight Time (11:51:30 G.M.T.): In his effort to advance the Art and Science of Aviation, to win the $25,000 Orteig Prize, to fly from New York to Paris, 25-year-old aviator Charles A. Lindbergh takes off from Roosevelt Field, Long Island, New York, United States of America, and heads north-eastward over the Atlantic Ocean on his solo, record-breaking flight to Paris, France, and into History.
The Spirit of St. Louis is pushed into position for takeoff at Roosevelt Field, 20 May 1927. (Underwood and Underwood, National Air and Space Museum Archives, Smithsonian Institution)Lindbergh taxis away from the crowd of spectators.
“I buckle my safety belt, pull goggles down over my eyes, turn to the men at the blocks, and nod.”
— The Spirit of St. Louis, by Charles A. Lindbergh, Charles Scribner’s Sons, 1953, at Page 185.
Spirit of St. Louis begins its takeoff run at Roosevelt Field, Long Island, New York, 20 May 1927.
As he circles to gain altitude after takeoff, Lindbergh scans his instruments.
“On the instrument board in front of me, the earth-inductor compass needle leans steeply to the right. I bank cautiously northward until it rises to the center line — 65 degrees — the compass heading for the first 100-mile segment of my great-circle route to France and Paris. It’s 7:54 a.m. Eastern daylight time.”
— The Spirit of St. Louis, by Charles A. Lindbergh, Charles Scribner’s Sons, 1953, at Page 189.
Great Circle route from the location of the former Roosevelt Field to Le Bourget, Paris: 3,145 nautical miles (3,619 statute miles/5,825 kilometers). (Great Circle Mapper)
