1 August 1955: Test pilot Anthony W. LeVier made the first flight flight of the Lockheed U-2 high-altitude reconnaissance airplane at Groom Lake, Nevada. LeVier was conducting taxi tests in preparation for the planned first flight a few days away, when at 70 knots the U-2 unexpectedly became airborne.
LeVier later said, “I had no intentions whatsoever of flying. I immediately started back toward the ground, but had difficutly determining my height because the lakebed had no markings to judge distance or height. I made contact with the ground in a left bank of approximately 10 degrees.”
On touching down on the dry lake, the U-2’s tires blew out and the brakes caught fire. A landing gear oleostrut was leaking. Damage was minor and the airplane was soon ready to fly. Tony LeVier was again in the cockpit for the first actual test flight on 4 August.
The Lockheed U-2A is a single-place, single-engine aircraft powered by a turbojet engine, intended for very high altitude photographic reconnaissance. Thirty U-2A aircraft were designed and built for the Central Intelligence Agency by Lockheed Aircraft Corporation’s secret “Skunk Works” under the supervision of Clarence L. “Kelly” Johnson.
Lockheed U-2, “Article 341,” at Groom Lake, Nevada, 1955. (Lockheed Martin)
The company designation for the proposed aircraft was CL-282. Its fuselage was very similar to the XF-104 Starfighter and could be built using the same tooling. The reconnaissance airplane was produced under the code name Operation AQUATONE.
The U-2A was 46 feet, 6 inches (14.173 meters) long with a wingspan of 80 feet (24.384 meters). Its empty weight was 10,700 pounds (5,307 kilograms) and the gross weight was 16,000 pounds (7,257 kilograms). The engine was a Pratt and Whitney J57-P-37A which produced 10,200 pounds of thrust. This gave the U-2A a maximum speed of 528 miles per hour (850 kilometers per hour) and a ceiling of 85,000 feet (25,908 meters). It had a range of 2,200 miles (3,541 kilometers).
Because of the very high altitudes that the U-2 was flown, the pilot had to wear a David Clark Co. MC-3 partial-pressure suit with an International Latex Corporation MA-2 helmet and faceplate. The partial-pressure suit used a system of capstans and air bladders to apply pressure to the body as a substitute for a loss of atmospheric pressure. Each suit was custom-tailored for the individual pilot.
Robert Sieker
On 4 April 1957, Article 341 was flown by Lockheed test pilot Robert Sieker. At 72,000 feet (21,946 meters) the engine flamed out and the cockpit pressurization failed. Parts of the U-2 had been coated with a plastic material designed to absorb radar pulses to provide a “stealth” capability. However, this material acted as insulation, trapping heat from the engine inside the fuselage. This lead to a number of engine flameouts.
Sieker’s partial-pressure suit inflated, but the helmet’s faceplate did not properly seal. He lost conciousness and at 65,000 feet (19,812 meters) the U-2 stalled, then entered a flat spin. Sieker eventually regained consciousness at lower altitude and bailed out. He was struck by the airplane’s tail and was killed. The first U-2 crashed northwest of Pioche, Nevada, and caught fire. Robert Sieker’s body was found approximately 200 feet (61 meters) away.
Because of the slow rate of descent of the airplane while in a flat spin, the impact was not severe. Portions of Article 341 that were not damaged by fire were salvaged by Lockheed and used to produce another airframe.
The first Lockheed U-2, “Article 341.” (Lockheed Martin)
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.
Lockheed test pilot Louis W. Schalk, Jr. (Lockheed Martin)
26 April 1962: At a non-existent location in the Mojave Desert of Nevada, Lockheed Chief Test Pilot Louis Wellington (“Lou”) Schalk, Jr., was scheduled to take the first Oxcart for a high-speed taxi test on the specially constructed 8,000-foot (2.44 kilometer) runway. However, he had received secret, specific instructions from designer Kelly Johnson to take the craft, known as “Article 121,” airborne.
Lou Schalk roared down the runway and lifted off. He flew at about 20 feet for two miles. The super-secret aircraft was oscillating badly so he set it down straight ahead on the dry lake bed and disappeared into a cloud of dust and flying sand. Johnson said that it “was horrible to watch.” A few minutes later, the needle nose of Article 121 appeared out of the dust as Schalk taxied back to the runway. It turned out that some equipment had been hooked up backwards. Subsequent flights were made without difficulty.
This was the actual first flight of the Central Intelligence Agency’s Top Secret A-12 reconnaissance aircraft. The “official” first flight would come several days later.
Lockheed A-12 60-6924 lands at Groom Lake, NV, after its first flight, 30 April 1962. (Lockheed Martin)
Designed as the successor to the Agency’s subsonic U-2 spy plane, the twin-engine jet was capable of flying more than Mach 3 (over 2,000 miles per hour/3,218.7 kilometers per hour) and higher than 80,000 feet (24,384 meters). Built by Lockheed’s “Skunk Works,” the new airplane wasn’t “state of the art,” it was well beyond the state of the art. New materials were developed. New equipment designed and built. New manufacturing processes were invented.
The A-12, developed under the code name “Oxcart,” was unlike anything anyone had ever seen. The first A-12 was referred to as Article 121. “A” = “Article.” “12-” is for A-12. “-1” is for the first production aircraft. So you get “Article 121.” What could be simpler?
The A-12 was so fast and could fly so high that it was invulnerable to any defense. No missile or aircraft or gun could reach it.
Lockheed A-12 Oxcarts and YF-12As at Groom Lake, Nevada. (Central Intelligence Agency)
Thirteen A-12s were built for the CIA. Two M-21 variants, built to carry the Mach 4 D-21 drone, were also produced. An interceptor version was developed for the Air Force as the YF-12A.
Ninety-three Lockheed F-12B interceptors were ordered though Secretary of Defense Robert S. McNamara refused to release the funding for production. After three years, the order was cancelled. The Air Force liked the A-12, however, and ordered 32 of the more widely known two-place SR-71A “Blackbird” reconnaissance ships.
Today, Article 121 is on display at the Blackbird Airpark, an annex of the Air Force Flight Test Museum, Edwards Air Force Base, California.
Lockheed YF-12A 60-6934, the first of three prototype Mach 3+ interceptors. (U.S. Air Force)
29 February 1964: President Lyndon B. Johnson publicly revealed the existence of the Top Secret Lockheed YF-12A, a Mach 3+ interceptor designed and built by Clarence L. “Kelly” Johnson’s “Skunk Works.” President Johnson referred to the interceptor as the “A-11.”
The following day, the Los Angeles Times ran two lengthy articles on its front page:
Johnson Discloses New Jet Secretly Developed by U.S.
Manned Aircraft Flies at 3 Times Speed of Sound; Military Potential Great
By ROBERT C. TOTH
Times National Science Correspondent
WASHINGTON—President Johnson disclosed Saturday the secret five-year development of an experimental jet aircraft whose performance “far exceeds that of any other aircraft in the world today.”
Several of the craft, designated A-11, have been “tested in sustained flight” at speeds greater than 2,000 m.p.h. and at heights over 70,000 ft., he said.
The craft has been made possible “by major advances in aircraft technology of great significance to both military and commercial application,” Mr. Johnson told a press conference.
Tests are under way at Edwards AFB, Cal., to determine the capability of the airplanes as long-range interceptors of enemy bombers. The plane was developed by Lockheed Aircraft Corp. of Burbank as a special project.
“Appropriate members of the Senate and the House have been kept fully informed on the program since its day of inception” in 1959, Mr. Johnson said.
Costs of the A-11 were not revealed, and the President said detailed performance information on the aircraft “will remain strictly classified.” Personnel working on the project have been told to keep quiet, he added.
Why the project has been wrapped in secrecy was not immediately clear. All that a White House spokesman would say, in answer to a question, was the A-11 represents “a new plateau in aircraft potential”—of such great potential that the military wanted to “explore it in secrecy.”
The A-11’s development also will aid in building a supersonic transport for commercial airlines, Mr. Johnson said. Like A-11, the transport would fly about Mach 3, or three times the speed of sound.
One of the most important technological achievements of the A-11 project, the President said, has been the mastery of the problem of using titanium metal on aircraft.
Great Heats
The aluminum used in today’s airplanes wears out in sustained flight at speeds greater than about Mach 2.2. This is due to the great heats generated by friction as air rushes over the surfaces of the aircraft, particularly the leading edges of the wings.
“The existence of this (A-11) program is being disclosed today to permit the orderly exploitation of this advanced technology in our military and commercial planes,” Mr. Johnson said.
High performance aircraft like the controversial TFX multi-service airplane and the Navy’s Phantom fighter will have speeds up to about Mach 2.5—about 1,600 m.p.h. These high speeds are possible for relatively short duration, however.
Funds for the A-11 were presumably buried in other appropriations, conceivably in part in Air Force appropriations for the B-70.
Dimensions of the A-11 were not revealed although an in-flight picture of the side view of the plane was distributed. It suggests the A-11 is more than 100 ft. long, based on the size of the pilot’s head in the cockpit.
The front half of the A-11 looks very similar to that of the X-15 rocket plane which has flown at speeds over 4,000 m.p.h. The characteristic tail surfaces of the X-15, extending both above and below the fuselage, also were obvious.
The A-11’s engine, a J-58 from Pratt & Whitney, occupies the rear third of the vehicle.
The experimental fire control and air-to-air missile system was developed by the Hughes Aircraft Co. The “A” in the aircraft’s designation suggests an “attack” function.
Number of Questions
Announcement of the project raises a number of questions, some of which Presidential Press Secretary Pierre Salinger answered at a subsequent briefing.
For example, why did the Pentagon object to the Boeing Aircraft Co.’s proposal to use titanium in the TFX if the A-11 had proved that the metal can be used?
“The technical knowledge obtained in the A-11 program made it possible to evaluate Boeing’s proposal,” Mr. Salinger said, and the Pentagon concluded that the titanium in the TFX represented a “High development risk.”
Technical Justification
This seemed to be further technical justification for the choice of General Dynamics over Boeing for the TFX, a choice which raised a political furor in Congress.
The economic meaning of the A-11 was another question put to Mr. Salinger. While the project makes a major contribution to Mach 3 flight, he replied, “It cannot be converted into a transport. A major independent development program is still necessary to produce a supersonic transport.”
—Los Angeles Times, Vol. LXXXIII, Sunday, 1 March 1964, Page 1, Columns 7–8, and Page 6, Columns 3–4
The second Times article identifies the designer as Clarence L. (“Kelly”) Johnson:
NEW PLANE GREAT FEAT OF SECURITY
BY MARVIN MILES
Times Aerospace Editor
President Johnson’s announcement of a new triple-sonic interceptor Saturday disclosed on of the best kept secrets in military annals, a security feat comparable in many ways to that achieved with the atomic bomb.
Apparently even the House Armed Services Committee didn’t know of the project for it recommended $40 million for an improved manned interceptor, a fund approved by the full House just 10 days ago.
The Senate, however, must have had more information, for it made no provision for the new interceptor studies in approving aircraft funding last Thursday, including $52 million for an advanced bomber.
The secret of Lockheed’s new A-11 interceptor was kept far better than that of the same company’s U-2 reconnaissance plane that was eventually shot down on a sky-spy flight over Russia.
Dozens of reports on the mysterious U-2 from various sections of the world had filtered into the news before the international incident over Russia.
The Times learned the new A-11 was spurred by the same aircraft genius who headed development of the U-2 and Lockheed’s famed F-104 Starfighter interceptor, Clarence (Kelly) Johnson, vice president for advanced development projects.
Johnson and his crew work in a carefully-guarded area at the Lockheed Burbank factory known as the “Skunk Works.”
Pierre Salinger, White House press officer, told newsmen the A-11 was funded and managed by the Air Force in the normal manner for a classified project.
Inasmuch as the new plane was started in 1959, this gave rise to speculation as to why a similar plane, the F-108, was canceled in that year.
The F-108 was a North American Aviation project in the same time era that the company’s triple-sonic B-70 bomber was started.
Like the A-11, it was to have had a speed of Mach 3 (about 2,000 m.p.h.) with a range of about 2,000 miles, plus combat time.
Reason for canceling the F-108 was largely budgetary, according to reports in 1959, with the Defense Department declaring that of the two North American projects, the B-70 bomber was a more urgent program than the F-108.
Some estimates of the A-11 can be drawn from the F-108. The North American plane was to have been powered by two engines, and one considered was the Pratt & Whitney J-58, the engine that will power the A-11.
This indicates the new Lockheed interceptor will have two engines also. The J-58 has never been used, either militarily or commercially, as far as The Times could determine. It has a thrust of about 30,000 lb.
Another indication from the F-108 relates to the armament of the A-11. The canceled North American interceptor was to have been armed with Hughes GAR-9 nuclear-tipped rockets.
The A-11 has a Hughes fire control system and its armament could well be the same guided, air-to-air rocket or an advancement of it.
The new interceptor will answer fears expressed by many military experts that Russia’s bomber fleet poses a greater threat to North America than her intercontinental missiles.
The A-11 will have the speed to intercept high speed bombers and shoot them down at ranges that would precluded their launching air-to-ground missiles against U.S. targets.
In appearance, the A-11 looks something like the X-15 rocket plane, a long, slim craft with sharp pointed nose section similar to that of the F-104 Starfighter.
It has both ventral and dorsal fins and appears to be about 90 ft. long over-all.
—Los Angeles Times, Vol. LXXXIII, Sunday, 1 March 1964, Page 1, Columns 7–8 and Page 6, Column 5–6
The YF-12A first flew 7 August 1963.
Clarence L. (“Kelly”) Johnson, Director of Lockheed’s Advanced Development Projects (“the Skunk Works”) with the first YF-12A interceptor, 60-6934. (Lockheed Martin)
Intended as a replacement for Convair’s F-106 Delta Dart, three pre-production YF-12As were built for testing. On 1 May 1965, a YF-12A set a speed record of 2,070.103 miles per hour (3,331.507 kilometers per hour) and reached an altitude of 80,259 ft (24,463 meters).
The reason for President Johnson’s announcement of the existence of the YF-12A prototypes was to conceal the existence of the Central Intelligence Agency’s fleet of Lockheed A-12 Oxcart reconnaissance aircraft based at Groom Lake, Nevada. Any sightings of these aircraft could be attributed to test flights of the YF-12As based at Edwards Air Force Base, 160 miles (258 kilometers) to the southwest.
Lockheed A-12 Oxcarts and YF-12As at Groom Lake, Nevada. (Central Intelligence Agency)
The YF-12A interceptor is very similar to its A-12 Oxcart and SR-71A Blackbird stablemates. It is a large twin-engine delta wing aircraft, flown by a pilot and weapons system operator. Because of the altitudes that the F-12 operates, the crew wears S901F full-pressure suits produced by the David Clark Company. The A-12 is 101.6 feet (30.97 meters) long with a wingspan of 55.62 feet (16.953 meters) and overall height of 18.45 feet (5.624 meters). It has a zero fuel weight of 54,600 pounds (24,766 kilograms) and a maximum ramp weight of 124,600 pounds (56,518 kilograms). ¹
Lockheed YF-12A three-view illustration. (NASA)
The YF-12A is powered by two Pratt & Whitney J58 (JT11D-20A) engines. These are single rotor bleed-bypass turbojets with a 9-stage compressor section and 2-stage turbine. They have a static thrust rating of 31,500 pounds (140.118 kilonewtons), each, at Sea Level with afterburning. The J58s use a unique JP-7 fuel.
The YF-12A has a maximum speed of Mach 3.35 (2,232 miles per hour/3,342 kilometers per hour) at 80,000 feet (24,384 meters). The A-12 has a normal operating cruise speed of Mach 3.1. Its maximum operating altitude is 85,000 feet (25,908 meters) and it has a range of 3,000 miles (4,828 kilometers). Unlike most fighters, the A-12 has a maximum load factor of 2.5 gs. Its maximum bank angle when above Mach 2.5 is 30°.
The United States Air Force ordered 93 production F-12B aircraft, which would have been armed with three Hughes AIM-47A Falcon air-to-air missiles in enclosed bays in the bottom of the fuselage. However, Secretary of Defense Robert S. McNamara refused to release the funds for the purchase for three consecutive years and eventually the project was cancelled.
Hughes AIM-47A guided missile ready for loading into the weapons bay of a Lockheed YF-12A. (U.S. Air Force)
The first YF-12A, 60-6934, seen in the top photograph, was extensively damaged by a brake system fire on landing at Edwards AFB, 14 August 1966. It was salvaged and rebuilt as SR-71C 61-7981. The third YF-12A, shown in the photograph below, was lost due to an inflight fire 24 June 1971. The crew safely ejected.
The only existing YF-12A, 60-6935, is in the collection of the National Museum of the United States Air Force at Wright-Patterson Air Force Base, Ohio.
Lockheed YF-12A 60-6936, holder of three World Absolute Speed Records and the World Absolute Altitude Record, at Edwards Air Force Base, California. (U.S. Air Force)
¹ The Lockheed SR-71A has a length of 107.4 feet (32.74 meters). Wingspan and height are the same. Its zero fuel weight varied from 56,500–60,000+ pounds (25,628–27,216+ kilograms) and the gross weight had a range of approximately 135,000–140,000+ pounds (61,235–63,503+ kilograms).
The prototype Lockheed Model 10 Electra X233Y in flight over Southern California, 1934. (James Borden Photography Collection)
24 February 1934:¹ Edmund Turney Allen,² a consulting engineer and test pilot, took the prototype Lockheed Model 10 Electra, serial number 1001, registered X233Y, for its first flight from the Lockheed Aircraft Corporation plant in Burbank, California, to the adjacent United Airport (which soon became United Air Terminal, then Lockheed Air Terminal and is now the Hollywood-Burbank Airport, BUR).
Aerial photograph of United Airport, looking west northwest, early 1930s. The Lockheed factory is just out of frame at the lower left, bordering the railroad tracks. (Burbank Public Library)
The Los Angeles Times reported:
NEW-TYPE PLANE PERFECTED
Lockheed Factory Turns Out First of “Electras,” Latest Word in Swift Transport
The latest forward step by Los Angeles in the field of swift-aircraft manufacture, a 215-mile-an-hour, ten-passenger, low-wing monoplane built by Lockheed Aircraft Corporation, made its first appearance and took to the air in its initial test flight yesterday.
The all-metal airliner, one of the fastest multimotored transport planes in the world and designed for economical performance by airlines enjoying little or no air-mail subsidy, was flown by Edmund T. Allen on its maiden flight from the Lockheed plant to United Airport, Burbank.
The ship, named the Electra, is the first of nine such planes ordered by two airlines, Northwest Airways having placed an order for three and Pan-American Airways awaiting delivery on six Electras. The model follows the single-engine Lockheed Vega, Orion and Sirius models flown by Col. Charles A. Lindbergh, Wiley Post, Col. Roscoe Turner, Amelia Earhart and other noted flyers on record flights.
The Electra’s cruising speed is in excess of 190 miles per hour. It is equipped with controllable-pitch propellers to gain maximum efficiency from its two Wasp Junior engines supercharged to develop 420 horsepower each at 5000 feet.
The craft is equipped with advanced improvements, including new retractable landing gear, wing flaps to insure low, safe landing speed, and a radical new-type tail assembly having two small vertical fins, or rudders,instead of one large one, making for greater maneuverability.
The Electra will be on display at United Airport, and the public, according to United Airlines officials, is invited to inspect it.
—Los Angeles Times, Vol. LIII, 25 February 1934, Page 17, Columns 1 and 2
The prototype Lockheed Electra Model 10 prototype, X233Y, at Union Airport, Burbank, California, before its first flight, 24 February 1934. (James Borden Photography Collection)
The Lockheed Model 10 Electra was designed as a 10-passenger commercial transport and was a contemporary of the Boeing Model 247. This was Lockheed’s first all-metal airplane. The Electra had two engines, a low wing and retractable landing gear. The airplane was designed by Lloyd Stearman and Hall L. Hibbard.
Lockheed Model 10 Electra X233Y. (aviadejavu)
A young engineer, Clarence L. (“Kelly”) Johnson, an assistant aerodynamicist at the University of Michigan, performed the wind tunnel tests on scale models of the proposed design and recommended changes to the configuration, such as the use of two vertical fins mounted at the outboard ends of the horizontal stabilizer. This became a design feature of Lockheed airplanes into the 1950s and included the Model 14 Super Electra/Hudson, Model 18 Lodestar/PV-1 Ventura, the P-38 Lightning fighter and the L-1649 Starliner, which was produced until 1958. Johnson would become the leader of Lockheed’s legendary “Skunk Works.”
Clarence L. “Kelly” Johnson conducted wind tunnel testing of the Model 10 at the University of Michigan. Note the single vertical fin on this wind tunnel model. (Lockheed)
The prototype Electra was was used for certification testing. During a full-load test at Mines Field (now, LAX, Los Angeles International Airport) the Electra’s landing gear malfunctioned. Marshall (“Babe”) Headle, Lockheed’s chief pilot, flew the airplane back to Burbank and made a one-wheel landing. The prototype was slightly damaged but quickly repaired.
Lockheed Model 10 Electra X233Y at Union Airport, Burbank, California, before its first flight, 24 February 1934. (James Borden Photography Collection)Lockheed Model 10 Electra X233Y at Union Airport, Burbank, California, before its first flight, 24 February 1934. (James Borden Photography Collection)Lockheed Model 10 Electra X233Y at Union Airport, Burbank, California, before its first flight, 24 February 1934. (James Borden Photography Collection)Passenger cabin of the Lockheed Model 10 Electra, looking forward. (James Borden Photography Collection)Lockheed Model 10 Electra NC233Y at Northwest Airways, St. Paul, Minnesota, May 1934. (James Borden Photography Collection)Lockheed Model 10 Electra NC233Y, Northwest Airways, St. Paul, Minnesota, 24 May 1934. (James Borden Photography Collection)Lockheed Model 10 Electra NC233Y, St. Paul Minnesota, 24 May 1934. (James Borden Photography Collection)
After testing was competed the prototype Electra was delivered to Northwest Airways, Inc., at St. Paul, Minnesota, in May 1934. The experimental registration was changed to a standard registration, NC233Y, and it was assigned the Northwest fleet number 60.
Like the Boeing 247, the Electra was originally produced with a forward-slanting windshield to prevent instrument light reflection during night flights. This resulted in ground lighting reflections, though, and was changed to a standard, rearward slant with the fifth production airplane. NC233Y was modified by Northwestern’s maintenance staff.
Lockheed built 147 Model 10s in various configurations. The first production variant was the Model 10A. It was 38 feet, 7 inches (11.760 meters) long with a wingspan of 55 feet (16.764 meters), and height of 10 feet, 1 inch (3.073 meters). The wings had a total area of 458.3 square feet (42.6square meters). Their angle of incidence was 0°, and there were 5° 34′ dihedral.
The airplane had an empty weight of 5,455 pounds (2,474 kilograms) and a gross weight of 9,000 pounds (4,082 kilograms).
Three-view illustration of initial configuration of the Lockheed Model 10 Electra.
The Model 10A was powered by two air-cooled, supercharged, 986.749-cubic-inch-displacement (16.170 liters) Pratt & Whitney Wasp Jr. SB 9-cylinder radial engines with a compression ratio of 6:1. They were rated at 400 horsepower at 2,200 r.p.m at 5,000 feet (1,524 meters), and 450 horsepower at 2,300 r.p.m. for takeoff, using 87-octane gasoline. The SB engines were direct-drive and turned two-bladed Smith variable-pitch propellers. The Wasp Jr. SB was 3 feet, 6.59 inches (1.056 meters) long, 3 feet, 11.75 inches (1.162 meters) in diameter, and weighed 645 pounds (293 kilograms). The engines were covered by NACA cowlings.
The airplane had a cruise speed of 190 miles per hour (306 kilometers per hour) at 5,000 feet (1,524 meters) and maximum speed of 215 miles per hour (346 kilometers per hour) at 8,000 feet (2,438 meters). The service ceiling was 20,000 feet (6,096 meters) and the range at cruise speed was 750 miles (1,207 kilometers).
The prototype Lockheed Model 10 Electra, NC233Y, after cockpit windshield modifications by Northwest Airways, Inc. (San Diego Air and Space Museum Archive, Catalog #: 01_00091576)
Newsreel footage of the Lockheed Model 10 prototype’s first flight, by cinematographer Alfred Dillimtash Black for Fox Movietone News, is in the collection of the Moving Image Research Collections, University of South Carolina, University Libraries, and can be viewed at: https://digital.tcl.sc.edu/digital/collection/MVTN/id/7073
The Electra was “the Lisbon plane” in the classic 1942 motion picture, “Casablanca,” which starred Humphrey Bogart, Ingrid Bergman, Paul Henreid and Claude Rains.
Probably the best-known Lockheed Electra is the Model 10E Special, NR16020, which was built for Amelia Earhart for her around-the-world flight attempt in 1937. She took delivery of the airplane on her 39th birthday, 24 July 1936.
Amelia Earhart with her Lockheed Electra 10E, NR16020, at Burbank, 1937.
The prototype Lockheed Model 10 later carried U.S. registrations NC2332, NC17380, and Canadian registration CF-BRG. It was placed in service with the Royal Canadian Air Force 2 August 1940 with the serial number 7652. One of 15 Lockheed Electras in RCAF service during World War II, it was destroyed by fire at RCAF Station Mountain View, Prince Edward County, Ontario, Canada, 14 October 1941.
Statement of Accident (Royal Canadian Air Force/Canadian Warplane Heritage Museum)
¹ Most sources cite 23 February as the date of the first flight.
² Many sources (e.g., Wikipedia) state that Lockheed’s Chief Pilot, Marshall Headle, made the Electra’s first flight.
