Amelia Earhart prepares to leave Burbank, California, 21 May 1937.
21 May 1937: Day 2 of Amelia Earhart’s second attempt to fly around the world aboard her Lockheed Electra 10E, NR16020. She and her navigator, Fred Noonan, fly from Union Air Terminal, Burbank, California, to Tucson, Arizona, where they stopped to refuel. Earhart’s husband, George Palmer Putnam, and aircraft mechanic Ruckins D. “Bo” McKneely were also aboard. ¹
When Earhart attempted to restart the left engine at Tucson, it caught fire. An unplanned overnight stay was required while the damage was repaired.
“Accompanying me on this hop across the continent was Fred Noonan. “Bo” McKneely my mechanic, and Mr. Putnam. A leisurely afternoon’s flight ended at Tucson, Arizona. The weather was sailing hot as Arizona can be in summertime. After landing and checking in, when I started my motors again to taxi to the filling pit the left one back-fired and burst into flames. For a few seconds it was nip-and-tuck whether the fire would get away from us. There weren’t adequate extinguishers ready on the ground but fortunately the Lux apparatus built in the engine killed the fire. The damage was trivial, mostly some pungently cooked rubber fittings a deal of dirty grime. The engine required a good cleaning and the ship a face-washing.”
—Amelia Earhart
¹ Although the standard Lockheed Electra 10E was certified to carry up to 10 passengers, the Restricted certification of NR16020 limited it to, “Only bona fide members of the crew to be carried.” The presence of Putnam and McKneely violated this restriction.
Great Circle route from the location of the former Union Air Terminal (now, Hollywood-Burbank Airport) to Davis-Monthan AFB, Tucson, Arizona: 396 nautical miles (455 statute miles/733 kilometers). (Great Circle Mapper)
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.
Lockheed XC-35 36-353 in flight. (U.S. Air Force)Headle
1 May 1937: The Lockheed Aircraft Company’s chief test pilot, Marshall Headle, took the Lockheed XC-35, Air Corps serial number 36-353, for its first flight. Ordered by the Air Corps in 1936 as a high-altitude research aircraft, and for the development of cabin pressurization, the XC-35 Supercharged Cabin Transport Airplane was a highly modified Lockheed Electra 10A. It was the first airplane to be specifically built with a pressurized cabin.
The Citizen-News, Hollywood, California, reported:
Mystery Airplane In Air For Tests
The Army’s secretly built stratosphere plane took off on its first test flight today at the Lockheed Aircraft Corp’s factory at Burbank with Marshall Headle, chief test pilot for the company, its sole occupant.
Only routine, low altitude maneuvers were to be carried out today, however, to test the plane’s flying characteristics, and it was expected that high altitude tests would not begin until next week.
Shortly before noon a canvas curtain that was erected about the mystery plane immediately after an unauthorized photograph brought stormy protests from the War Dept., was lowered and the big twin engined, low wing craft rumbled to the end of the factory airport.
A quick sprint and the silver bodied plane was in the air safely.
Company officials continued their silence on performance expected of the military experimental ship.
The XC-35 had been rolled out of the plant several days earlier. It was photographed by a newspaper photographer and the image published in a local newspaper. The photographer had hidden behind bushes on a small hill near the plant. This resulted in an immediate response from the military, with the airplane being hidden behind a canvas enclosure. Armed guards were ordered to “shoot cameras out of the hands of photographers and ask questions afterward—but to destroy all cameras.” There were also roving vehicle patrols, etc. Army intelligence officers interrogated the photographer.
The Army Air Corps was awarded the Collier Trophy for 1937 for the XC-35 project.
With a strengthened circular fuselage and smaller windows, the XC-35′s passenger compartment was pressurized by engine turbo-superchargers and controlled by a flight engineer. Cabin pressure could be maintained at the equivalent of 12,000 feet (3,658 meters) above sea level, at an actual altitude of 30,000 feet (9,144 meters).
Lockheed XC-35 engineer station. (U.S. Air Force)
A crew of three and two passengers were accommodated within the pressurized section, and there was room for another passenger to the rear of the pressure bulkhead, which could only be used at lower altitudes.
Lockheed XC-35 36-353.
The Lockheed XC-35 was similar to the Lockheed Model 10 Electra, with the same dimensions: length, 38 feet, 7 inches (11.760 meters), wingspan 55 feet (16.764 meters), and height, 10 feet, 1 inch (3.073 meters). It had a total wing area of 458.5 square feet (42.596 square meters). The airplane had an empty weight of 7,940 pounds (3,602 kilograms), and gross weight of 10,500 pounds (4,763 kilograms).
The Lockheed XC-35 was powered by two air-cooled, supercharged, 1,343.804-cubic-inch-displacement (22.021 liter) Pratt & Whitney R-1340-43 (Wasp T5H1) single-row, nine-cylinder radial engines with a compression ratio of 6:1. The R-1340-43 had a Normal and Takeoff Power rating of 550 horsepower at 2,200 r.p.m. from Sea Level to 3,000 feet (914 meters), burning 92-octane gasoline. It was direct drive. The engine was 3 feet, 6.25 inches (1.073 meters) long, 4 feet, 3.50 inches (1.308 meters) in diameter, and weighed 864 pounds (392 kilograms). The engines drove two-bladed, variable pitch propellers.
The XC-35 had a cruise speed of 214 miles per hour (344 kilometers per hour), and maximum speed of 236 miles per hour (380 kilometers per hour) at 20,000 feet (6,096 meters). It could climb at a rate of 1,125 feet per minute (5.7 meters per second), and its service ceiling was 31,500 feet (9,601 meters).
Able to fly above 30,000 feet (9,144 meters), the XC-35 was later used by NACA for thunderstorm penetration research flights. In 1948 it was transferred to the Smithsonian Institution.
