Tag Archives: Pratt & Whitney Wasp S3H1

15 August 1935

Will Rogers and Wiley Post with the Lockheed Model 9E Orion hybrid at Renton, Washington. The pontoons have just been installed on the airplane in place of its fixed landing gear. (Unattributed)
Will Rogers and Wiley Post with the Lockheed Model 9E Orion hybrid at Renton, Washington. The pontoons have just been installed on the airplane in place of its fixed landing gear. (Seattle Post Intelligencer Collection/Museum of History & Industry)

15 August 1935: Two of the most famous men of their time, Wiley Hardeman Post and William Penn Adair (“Will”) Rogers, were killed in an airplane crash near Point Barrow, Alaska.

Post, a pioneering aviator who had twice flown around the world—once, solo—and helped develop the pressure suit for high altitude flight, was exploring a possible air mail route from the United States to Russia. His friend, world famous humorist Will Rogers, was along for the trip.

Transcontinental and Western Airlines' Lockheed Model 9E special, NC12283. This airplane would be modified by Pacific Airmotive, Burbank, California, for Wiley Hardeman post. (Ed Coates Collection)
Transcontinental & Western Air Incorporated’s Lockheed Model 9E Special, NC12283. This airplane would be modified by Pacific Airmotive, Burbank, California, for Wiley Hardeman Post. (Ed Coates Collection)

Post’s airplane was a hybrid, built from the fuselage of a former Transcontinental & Western Air, Inc., Lockheed Model 9E Orion Special, NC12283, combined with a wing from a Lockheed Model 7 Explorer. T&WA operated the Orion for two years before selling it to Charles Babb, Glendale, California. Babb installed the salvaged wing from a modified Lockheed Model 7 Explorer, Blue Flash, NR101W, which had crashed in Panama in 1930.

The Orion’s standard 450 horsepower Pratt & Whitney Wasp SC1 engine was replaced with an air-cooled, supercharged, 1,343.8-cubic-inch-displacement (22.021 liter) Pratt & Whitney Wasp S3H1 nine-cylinder radial engine (serial number 5778), rated at 550 horsepower at 2,200 r.p.m. to 5,000 feet (1,524 meters), and 600 horsepower at 2,250 r.p.m. for takeoff. A three-bladed Hamilton Standard variable-pitch propeller was used. Both the SC1 and S3H1 were direct drive engines. The S3H1 was 3 feet, 7.01 inches (1.093 meters) long and 4 feet, 3.60 inches (1.311 meters) in diameter. It weighed 865 pounds (392 kilograms).

Post also wanted to replace the retractable landing gear with pontoons for water landings.

Lockheed engineers were of the opinion that the hybrid aircraft and the other modifications which were requested by Post were dangerous and refused to do the work. Pacific Airmotive, also located in Burbank, California, however, agreed to modify the airplane. Several names were used to describe the hybrid airplane, such as “Lockheed Aurora,” as well as others perhaps less polite. It was given the restricted registration NR12283.

NR12283 was 27 feet, 6 inches (8.382 meters) long with a wingspan of 48 feet, 6 inches (14.783 meters). The wing area was 313 square feet (29.079 square meters).

Wiley Post’s red Lockheed Orion/Explorer hybrid, NR12283, at Renton, Washington.

Post had the pontoons installed at Renton, Washington. The floats that he had ordered did not arrive on time so he installed a larger set intended for another aircraft.

NR12283, Wiley Post's hybrid Lockheed Orion/Explorer float plane, at Fairbanks, Alaska. (PBS)
NR12283, Wiley Post’s red hybrid Lockheed Orion/Explorer float plane, at Fairbanks, Alaska. (PBS)

After several days of flying from Seattle and through Alaska, Post and Rogers were nearing Point Barrow on the northern coast of the continent. They encountered dense fog and landed on Walakpa Bay, about 13 miles (21 kilometers) southwest of the village of Barrow.

After talking with a local resident, Clair Okpheah, they taxied back on the lagoon and took off to the north. Post banked to the right, but at about 50 feet (15 meters) the engine stopped. NR12283 pitched down, rolled to the right, and then its right wing struck the mud. The right wing and pontoon were torn off and the airplane crashed upside down. Post and Rogers died.

Clair Okpheah ran to Barrow for help. When a rescue party arrived 16 hours after the crash, the men recovered the bodies of Post and Rogers. It was noted that Wiley Post’s wristwatch had stopped at 8:18 p.m.

Wiley Post's hybrid airplane, NR12283, after the crash, 15 August 1935. (UPI)
The wreckage of Wiley Post’s Lockheed Model 9E Orion hybrid airplane, NR12283, after the crash at Walakpa Lagoon, Alsaka, 15 August 1935. (UPI)

© 2016, Bryan R. Swopes

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24 July 1936

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

24 July 1936: On her 39th birthday, at the Union Air Terminal, Burbank, California, Amelia Earhart accepted delivery of her new Lockheed Electra 10E Special, registered NR16020.

$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.

Amelia Earhart and her Lockeed Electra.
Amelia Earhart and her Lockeed Electra.

The Electra Model 10 was manufactured by the Lockheed Aircraft Company at Burbank, California. It 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 in the cocpit of her Lockheed Electra 10E, NR16020.
Amelia Earhart in the cockpit of her Lockheed Electra 10E Special, NR16020. The Sperry GyroPilot is at the center of the instrument panel. (AFP/Getty Images)

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. Additional 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 the autopilot, navigation equipment and additional batteries. These modifications varied from the standard airplane enough that it was restricted to carrying only members of required flight crew. This was denoted by the letter “R” in the airplane’s registration.

Amelia Earhart stands behind the additional fuel tanks installed in the aft cabin of her Electra. (AP)
Photographed from the navigator’s station at the rear of the passenger cabin, Amelia Earhart leans over the additional fuel tanks installed in her Electra. (AP)

The Electra was not ready until mid-July. Earhart first flew the new airplane on 21 July with Lockheed test pilot Elmer C. McLeod.

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 and 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.

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 & Whitney Wasp S3H 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 two-bladed Hamilton Standard 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).

The maximum speed for the Model 10E Special at Sea Level and maximum takeoff weight was 177 miles per hour (285 kilometers per hour), a reduction of 25 miles per hour (40 kilometers per hour) over the standard airplane. The maximum range was calculated to be 4,500 miles (7,242 kilometers)

Lockheed test pilot Elmer C. McCleod with a Lockheed Model 10 Electra, "Phantom of the Sky." (Lockheed Martin via dmairfield.com)
Lockheed test pilot Elmer C. McCleod with a Lockheed Model 10 Electra, “Phantom of the Sky.” (Lockheed Martin via dmairfield.com)

© 2017, Bryan R. Swopes

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Amelia Earhart’s Lockheed Electra 10E Special, NR16020

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)

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.

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 light blue 1936 Cord 810 convertible. (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)

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.

© 2016, Bryan R. Swopes

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22 May 1937

Amelia Earhart's Lockheed Electra 10E, NR16020
Amelia Earhart’s Lockheed Electra 10E Special, NR16020

22 May 1937: Earhart’s Lockheed Electra 10E Special, NR16020 was repaired at Tucson, Arizona after its left engine, a Pratt & Whitney Wasp S3H1 nine-cylinder radial, caught fire while restarting after a fuel stop the previous day. Amelia Earhart and her Navigator, Fred Noonan, and two passengers, flew to New Orleans, Louisiana, on the 22nd. Although she was on the third leg of her second around-the-world-flight attempt, no public announcement had yet been made.

“The next morning at Tucson a dense sandstorm blocked our way, but despite it we took off, leap-frogging at 8,000 feet over El Paso with a seemingly solid mass of sand billowing below us like a turbulent yellow sea. That night we reached New Orleans. . . .” — Amelia Earhart

© 2017, Bryan R. Swopes

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17 March 1937

Another camera angle shows Amelia Earhart taking off from Oakland Municipal Airport, 17 March 1937. (© Bettman/CORBIS)
This photograph shows Amelia Earhart taking off from Oakland Municipal Airport,  4:37 p.m., 17 March 1937. (© Bettman/CORBIS)

17 March 1937, 4:37 p.m.: Amelia Mary Earhart departed Oakland Municipal Airport, on the east shore of San Francisco Bay, starting the first leg of her around-the-world flight. Also aboard were her friend and adviser, Albert Paul Mantz, navigator Frederick J. Noonan and radio operator/navigator Harry Manning. The airplane was Earhart’s Lockheed Electra 10E Special, NR16020.

Amelia Earhart and her crew pose in front of the Electra. Left to right, Paul Mantz, co-pilot; Amelia Earhart, pilot; Captain Harry V. Manning, radio operator/navigator; and Captain Frederick J. Noonan, also a navigator, at Oakland Municipal Airport, California, 17 March 1937.
Amelia Earhart and her crew pose in front of the Electra. Left to right, Paul Mantz, co-pilot; Amelia Earhart, pilot; Captain Harry Manning, radio operator/navigator; and Captain Frederick J. Noonan, also a navigator, at Oakland Municipal Airport, California, 17 March 1937.

Captain Frederick J. Noonan was formerly the Chief Navigator of Pan American Airways, and had extensive experience in transoceanic flight. Captain Harry Manning commanded ocean liners. He would later serve as captain of SS United States, the flagship of America’s Merchant Marine, and Commodore of United States Lines.

Checking weight and balance and fuel quantity calibration at Lockheed, Burbank, California. (Purdue)
Checking weight and balance and fuel quantity calibration at Lockheed, Burbank, California. (Purdue University Library)

Amelia Earhart’s 1936 Electra 10E Special, serial number 1055, was the fifth of fifteen built by the Lockheed Aircraft Corporation at Union Air Terminal, Burbank, California (now, Hollywood Burbank Airport, BUR). Designed to carry as many as ten passengers, NR16020 had been modified to carry fuel for 20 hours of flight. Amelia first flew the Electra with a Lockheed test pilot, Elmer C. McLeod, 21 July 1936, and took delivery on her 39th birthday, 24 July. The airplane cost $80,000.

Kelly Johnson with a wind tunnel model of a version of the Lockheed Electra. Based on testing, numerous changes were made before the airplane was placed in production.
Kelly Johnson with a wind tunnel model of a version of the Lockheed Electra. Based on testing, numerous changes were made before the airplane was placed in production. (Lockheed)

The Lockheed Electra 10 was designed by Hall Hibbard, and was Clarence L. “Kelly” Johnson’s first assignment when he went to work at Lockheed. It was 38 feet, 7 inches (11.760 meters) long with a wingspan of 55 feet, 0 inches (16.764 meters) and overall height of 10 feet, 1 inch (3.073 meters).

While the basic Model 10 had an empty weight of 6,454 pounds (2,927.5 kilograms), Amelia Earhart’s modified Electra 10E Special had an empty weight of 7,265 pounds (3,295.4 kilograms), partly as a result of the additional fuel tanks which had been installed. Fully fueled, NR16020 carried 1,151 gallons (4,357 liters) of gasoline.

NR19020 was powered by two air-cooled, supercharged, 1,343.804-cubic-inch-displacement (22.021 liter) Pratt & Whitney Wasp S3H1 single-row nine-cylinder radial engines with a compression ratio of 6:1. These engines used a single-stage supercharger. The S3H1 had a Normal Power rating of 550 horsepower at 2,200 r.p.m. to 5,000 feet (1,524 meters), and 600 horsepower at 2,250 r.p.m for Takeoff, using 80/87 aviation gasoline. The direct-drive engines turned two-bladed Hamilton Standard variable-pitch, constant-speed propellers with a diameter of 9 feet, 7/8-inch (2.675 meters). The Wasp S3H1 was 3 feet, 7.01 inches (1.092 meters) long, 4 feet, 3.60 inches (1.311 meters) in diameter, and weighed 865 pounds (392 kilograms).

Amelia Earhart's Lockheed Electra 10-E, taking off from Oakland Airport, 1637 hours, 17 March 1937. The tail wheel has just lifted off the runway.
Amelia Earhart’s Lockheed Electra 10E, NR16020, taking off from Oakland Airport, 1637 hours, 17 March 1937. The tail wheel has just lifted off the runway.
Amelia Earhart's Lockheed Electra 10E, NR16020, departs Oakland, 4:37 p.m., 17 March 1937. (Purdue University Library)
Amelia Earhart’s Lockheed Electra 10E, NR16020, departs Oakland, 4:37 p.m., 17 March 1937. The landing gear is retracting. (Purdue University Library)
Amelia Earhart's Lockheed Electra 10E, NR16020, over San Francisco Bay, enroute Hawaii, 17 March 1937. (Clyde Sunderland)
Amelia Earhart’s Lockheed Electra 10E, NR16020, over San Francisco Bay, enroute Hawaii, 17 March 1937. (Clyde Sunderland)

© 2017, Bryan R. Swopes

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