Tag Archives: Lockheed L-1049 Super Constellation

9 January 1943

Lockheed L-049 Constellation NX25600 in flight. (San Diego Air and Space Museum Archive)
Lockheed XC-69 Constellation 43-10309 (L-049 NX25600) in flight. (San Diego Air & Space Museum Archive)

9 January 1943: At the insistence of the United States Army Air Forces, Boeing’s Chief Test Pilot, Eddie Allen, made the first flight of the Lockheed L-049 Constellation prototype, NX25600, from Lockheed Air Terminal at Burbank, California, to Muroc Army Airfield (today known as Edwards Air Force Base). Lockheed’s Chief Test Pilot, Milo G. Burcham, was the co-pilot.

Lockheed XC-69 Constellation 43-10309 (L-049 NX25600) in flight. (San Diego Air & Space Museum Archive)

Also on board were Lockheed’s chief research engineer, Clarence L. (“Kelly”) Johnson; Rudy Thoren, Johnson’s assistant; and Dick Stanton, chief mechanic.

The Lockheed Constellation was designed by a team led by Chief Engineer Hall Livingstone Hibbard, left, and Chief Research Engineer Clarence Leonard “Kelly” Johnson. (Lockheed)

When the flight ended after 58 minutes, Allen said, “This machine works so well that you don’t need me anymore!” With that, Allen returned to Seattle.

The Los Angeles Times reported:


Lockheed’s Air Marvel Makes First Flight; Believed to Be World’s Largest and Fastest; Built Like Fighter, Can Outspeed Jap Zero


     Into the winter sky yesterday swept a brilliant new star—Lockheed super-transport Constellation.

     First of a galaxy to come, the four-engine colossus sped down the long east-west runway at Lockheed Air Terminal, skipped nimbly off the concrete and boomed upward with the surging roar of 8000 unleashed horses.

     A few breath-taking seconds’ full throttle had written a matter-of-fact climax to two years of secret development that evolved a 60-passenger transport faster than a Jap Zero fighter.

     There were no fanfares, no speeches—simply an unvarnished war production takeoff, emphasizing as nothing else could the grim driving need for huge work planes to carry the battle swiftly to the ends of the earth.

     Yet it was the first significant aviation event of 1943.

Lockheed XC-69 Constellation 43-30109 during its first flight, 9 January 1943. (Lockheed Martin Aeronautics Company)

     Built along the slim, graceful lines of a fighter the craft is faster than any four-engine bomber now in service. It can cross the continent in less than 9 hours,fly to Honolulu in 12. Even at half power its cruising speed is approximately 100 miles per hour faster than that of a standard airliner!

     Within its supercharged cabin, air-density will remain at the 8000-foot level when the Constellation is cruising at “over-the-weather” altitudes up to 35,000 feet. So great is its power that the monster can maintain 25,000 feet on three engines, 16,500 on two.

     As for economy of operation, the new sky queen can fly her full load hour after hour using but one gallon of gasoline per mile.

Lockheed XC-69 Constellation 43-10309 (L-049 NX25600) at Lockheed Air Terminal, with engines running. Looking west-northwest across the San Fernando Valley. (San Diego Air & Space Museum Archive)


     At the controls when the super-transport lifted its tricycle gear in flight were Eddie Allen, Army pilot and veteran four-engine flyer, and Milo Burcham, Lockheed test pilot noted for his substratosphere testing of the P-38. Also in the ship were C.L. (Kelly) Johnson, chief research engineer for the aircraft company; Rudy Thoren, Johnson’s assistant, and Dick Stanton, chief mechanic.

Chief Research Engineer Clarence L. “Kelly” Johnson (left) and Chief Engineering Test Pilot Milo G. Burcham, with the XC-69 Constellation. (Lockheed Martin Aeronautics Company)

    There was but one taxi test yesterday, highlighted by a brief blaze in one of the four engines following a backfire as the ship turned to roll back to the head of the runway.

     The fire was doused quickly and the Constellation stood ready for her maiden flight, he nose into a gentle breeze, the focal point of hundreds of eyes of workers, Army guards and officials watched expectantly.

     Each engine “revved up”in turn, sending deep-throated echoes over the sun-drenched terminal.

     Then the four black propellers whirled as one.

     The Constellation shot forward, the wind in her teeth, a hurtling, bellowing land monster—until her propellers plucked her from the earth in an incredibly short span of runway and sent her thundering triumphantly toward the sun.


      In a moment she had almost vanished, only to bank in a wide turn and drone back over the terminal twice before leading her covey of lesser following craft off toward the desert to the Army airport at Muroc Dry Lake where she landed gracefully an hour later.

Prototype Lockheed Constellation at Muroc Dry Lake, 1942. (Unattributed)
Prototype Lockheed L-049 Constellation NX25600 at Muroc Dry Lake on the high desert of southern California, 9 January 1943. (San Diego Air & Space Museum Archive)

     Shortly before dusk the giant craft returned to the Burbank terminal, slipped down the long “landing groove” of air and settled easily to the runway.

     Her debut was over.

     Today she will begin the exhaustive test flights to determine her performance before she is turned over to T.W.A. and the Army for the grueling business of war. . . .

Los Angeles Times, Vol. LXII, Sunday morning, 10 January 1943, Page 1, Columns 1 and 2; Page 2, Columns 2 and 3. The article continues in Column 4. (The photographs are not a part of the original article.)

The prototype Lockheed XC-69, 43-10309 (NX25600), landing at Lockheed Air Terminal, Burbank, California, 1943. (Lockheed Martin Aeronautics Company)

The Lockheed Model 49-46-10, company serial number 049-1961, was designated XC-69 by the U.S. Army Air Forces and assigned serial number 43-10309.

The Constellation was operated by a flight crew of four: two pilots, a navigator and a flight engineer. It could carry up to 81 passengers. The airplane was 95 feet, 1 316 inches (28.986 meters) long with a wingspan of 123 feet, 0 inches (37.490 meters), and overall height of 23 feet, 7⅞ inches (7.210 meters). It had an empty weight of 49,392 pounds (22,403.8 kilograms) and maximum takeoff weight of 86,250 pounds (39,122.3 kilograms).

The XC-69 was powered by four air-cooled, supercharged, 3,347.662-cubic-inch-displacement (54.858 liter), Wright Aeronautical Division Cyclone 18 745C18BA2 engines. Also known as the Duplex Cyclone, these were a two-row, 18-cylinder radial engines with a compression ratio of 6.5:1, which required 100/130-octane aviation gasoline. They were rated at 2,000 horsepower at 2,400 r.p.m., or 2,200 horsepower at 2,800 r.p.m. for takeoff, (five minute limit). The 745C18BA2 was 6 feet, 4.26 inches (1.937 meters) long, 4 feet, 7.78 inches (1.417 meters) in diameter and weighed 2,595 pounds (1,177 kilograms). The engines drove 15 foot, 2 inch (4.623 meter) diameter, three-bladed Hamilton Standard Hydromatic 43E60 constant-speed propellers through a 0.4375:1 gear reduction.

The L-049 had a cruise speed of 313 miles per hour (504 kilometers per hour) and a range of 3,995 miles (6,429 kilometers). Its service ceiling was 25,300 feet (7,711 meters).

In this photograph of the Lockheed XC-69 prototype, the civil experimental registration numbers, NX25600 are visible under the left wing. (Unattributed)
In this photograph of the Lockheed XC-69 prototype at Lockheed Air Terminal, the civil experimental registration numbers, NX25600, are visible on the rudder and under the left wing. Looking northeast, the Verdugo Mountains of Southern California are in the background. (San Diego Air & Space Museum Archive)
This is a rare color photograph of the prototype Lockheed XC-69 Constellation, 43-10309, (L-049 NX-25600) with a Lockheed UC-101, 42-94148 (ex-Vega 5C NC14236) at Lockheed Air Terminal, Burbank California. This picture represents 15 years of technological advancement. (Lockheed Martin Aeronautics Company)

The prototype XC-69 was later re-engined with Pratt & Whitney Double Wasp 2SC14-G (R-2800-83) engines and designated XC-69E. These had a Normal rating of 1,700 horsepower at 2,600 r.p.m., to 7,300 feet (2,225 meters), 1,500 horsepower at 17,500 feet (5,334 meters), and 2,100 horsepower at 2,800 r.p.m. for Takeoff.

Lockheed XC-69 Constellation 43-10309. (Lockheed Martin Aeronautics Company)
Lockheed XC-69 Constellation 43-10309. (Lockheed Martin Aeronautics Company)

After the war, the Constellation prototype was sold to Howard Hughes’ Hughes Aircraft Company for $20,000 and registered as NX67900. In May 1950, Lockheed bought the prototype back from Hughes for $100,000 and it was again registered as NC25600. It had accumulated just 404 flight hours up to this time.

The prototype Lockheed XC-69 Constellation, 43-10309, is parked at Howard Hughes’ Culver City airport. In the foreground is the Hughes XF-11, 44-70155. Photographed 7 July 1946. (University of Nevada, Las Vegas Libraries)
Lockheed L-1049 Super Constellation prototype, NX6700, ex-L-049 NX25600. (Lockheed Martin)
The prototype Lockheed L-1049 Super Constellation NX25600 (XC-69 43-10309), flying above an inversion layer. The San Gabriel Mountains of Southern California are in the background. (Lockheed Martin Aeronautics Company)

Lockheed then converted 049-1961 to a prototype for the L-1049 Super Constellation with another registration, NX6700. In 1952, it was once again converted, this time as an aerodynamic test aircraft for the U.S. Navy PO-1W radar early warning aircraft (later redesignated WV-1 and EC-121 Warning Star). It was also used to test the Allison YT56 turboprop engine by placing it in the position.

Lockheed L-1049 prototype NX6700 as an aerodynamics test aircraft for the U.S. Navy PO-1W airborne early warning Warning Star. (SDASM Archives)

Finally, in 1958, the first Constellation was purchased as a source of spare parts by California Airmotive Corporation and was dismantled.

Lockheed built two XC-69 prototypes. Twenty-two C-69s and 856 Constellations of all types were produced. The Lockheed Constellation was in production from 1943–1958 in both civilian airliner and military transport versions. It is the classic propeller-driven transcontinental and transoceanic airliner.

Your intrepid TDiA correspondent with “Bataan,” General Douglas MacArthur’s Lockheed VC-121A Constellation, 48-613, at Valle Airport, Arizona, 3 July 2012. (Photograph by Mrs. TDiA)

© 2019, Bryan R. Swopes

13 October 1950: Lockheed L-1049 Super Constellation

The prototype Lockheed L-1049 Super Constellation, N67900. (Lockheed Martin Aeronautics Company)

13 October 1950: The prototype Lockheed L-1049 Super Constellation made its first flight at the Lockheed Air Terminal in Burbank, California.

With the expansion in commercial air travel immediately following World War II, airlines required transports with longer range and greater passenger and cargo capacity. They needed airplanes that could provide lower seat-per-mile operating costs than existing types.

To meet these needs, Lockheed considered discontinuing production of the the current L-749 Constellation in favor of developing a completely new turbojet-powered transport. But due to the the time required to design and produce such a completely new design, and the much greater fuel consumption of jet engines, Lockheed determined that the most efficient course would be to improve the existing L-749 Constellation’s design to increase its load carrying capability.

Design of the L-1049 Super Constellation started February 1950, with the design team led by Kelly Johnson.

Lockheed XC-69 Constellation 43-10309 (L-049 NX25600) at the Lockheed Air Terminal, Burbank, California. (Lockheed Martin Aeronautics Company)

Instead of building a complete new airplane, the original XC-69 prototype, which had been parked at Howard Hughes’ private airport near Culver City, was purchased by Lockheed and flown back to the Lockheed Air Terminal in Burbank. After the war, the Constellation prototype was sold to Howard Hughes’ Hughes Aircraft Company for $20,000 and registered as NX67900. In May 1950, Lockheed bought the prototype back from Hughes for $100,000 and it was again registered as NC25600. It had accumulated just 404 flight hours up to this time.

The Lockheed XC-69 Constellation prototype, 43-10309, is parked behind the Hughes XF-11, 44-70155, at Culver City, California, 7 July 1946. (University of Nevada, Las Vegas Libraries)

The XC-69 was cut into three sections. A 10 foot, 8.8 inch (3.272 meters) long, 11 foot, 7.3 inch (3.538 meter) diameter, cylindrical section was added forward of the front wing spar, and a 7 foot, 8 inch (2.337 meters) cylindrical section with the same diameter, aft of the rear spar.

The wings, fuselage and landing gear of the L-1049 were strengthened for increased gross weight. The height of the vertical fins was increased 2.5 inches (6.35 centimeters) for improved longitudinal stability. The cabin floor area was increased by 33% to 744 square feet, and cargo volume, 51% to 656 cubic feet.

Lockheed L-1049 Super Constellation three-view illustration with dimensions. (Lockheed Aircraft Corporation)

The L-1049 had accommodations for 76–94 passengers and crew. (The L-749A Constellation carried 47–63). Other changes included a 25% increase in cockpit window height, and square passenger windows (a requirement of Northwest Airlines). The fuel load was increased by 5,000 pounds, and the range by 300 miles. The Super Constellation’s cruise speed was cruise speed 25–40 m.p.h. slower due to the increased weight.

L-1049 serial numbers 4001–4014 had cockpit stations for a pilot, copilot, flight engineer and an observer. Beginning with 4015, a radio operator’s station as added.

Illustration of the Super Constellation’s general arrangement from Lockheed Report 7786 Crew Operating Manual for Lockheed Model 1049 Super Constellation Air[planes, revised 1 May 1952. (Lockheed Aircraft Corporation)
Total fuel capacity was 3,660 U.S. gallons (13,855 liters). Each engine was supplied by engine oil tank with a capacity of 49 gallons (185.5 liters).

The first production Lockheed L-1049 Super Constellation, s/n 4001, N6201C. (Lockheed Martin Aeronautics Company)

The L-1049 was powered by four air-cooled, direct-fuel-injected, 3,347.662 cubic-inch-displacement (54.858 liters) Wright Aeronautical Division 956C18CA1 eighteen-cylinder turbocompound radial engines with a compression ratio of 6.70:1. The turbocompound engine used captured exhaust gases to drive three Power Recovery Turbines. These PRTs were coupled to the engine’s crankshaft. This system added approximately 450 horsepower to the engine’s total power output.

The 956C18CA1 had a continuous power rating of 2,300 horsepower at 2,600 r.p.m., and 2,700 horsepower at 2,900 r.p.m. for takeoff. The engines turned three-bladed Hamilton Standard propellers through a 0.4375:1 propeller gear reduction. The engine was 6 feet, 6.47 inches (1.993 meters) long, 4 feet, 7.62 inches (1.413 meters) in diameter, and weighed 2,962 pounds (1,343.5 kilograms).

The L-1049 had a maximum speed (VNO) of 260 knots (299 miles per hour/482 kilometers per hour) from Sea Level to 11,000 feet (3,353 meters). Above that altitude, speed was reduced by 9 knots (10 miles per hour/17 kilometers per hour) for each 2,000 foot (610 meters) increase. Maneuvering speed (VA) was 180 knots (207 miles per hour/333 kilometers per hour). The maximum operating altitude was 25,000 feet (7,620 meters). The cabin was pressurized to 5.5 p.s.i. (0.379 Bar).

The Los Angeles Times reported:

“NEXT THING TO JET—Eighteen feet longer than the standard Connie, Lockheed’s new Super Constellation is announced “to bridge the gap between modern planes and the first American jet transport.” Fifty million dollars in orders have been received.”


Giant Constellation Carries 110 Passengers
Is Forerunner of Transocean Jet Aircraft

     Lockheed’s new Super Constellation—18.4 feet longer than the standard Connie—was announced yesterday as “designed to bridge the gap between modern planes and the first Americanjet transport.”

     Similar in appearance to its famous predecessor, the prototype of the new ship was flown for the first time last Friday, out of Lockheed Air terminal, Burbank, officials said.

     It will be introduced into service with the latest type reciprocating engines, subsequently will be powered with new compound engine and finally will utilize turbo-prop engines as the final link with pure jet transports of the future.

     “The new transport will incorporate much of the proven design and equipment of the current Constellation,” Lockheed spokesmen said, “and at the same time will carry all available modern features that testing has proved worthwhile.”

     Among teh latter will be electro-pneumatic de-icing such as is used on Lockheed’s high-speed jet aircraft. Old-type rubber boot and hot air de-icing has been found inadequate for higher speeds and altitudes, it was explained.

     The Super Connie is described as “the first truly nonstop trans-Atalantic transport ever built, 50 m.p.h. faster on over-ocean runs than competitive airplanes.”

     Measuring 113 feet 7 inches from nose to tail, its cabin will carry 76 standard-fare passengers or up to 110 coach fare, 35% more than present Constellations, with 72% more space for baggage and cargo.

Big Navy Engines

     The Super Connie is said to be the only transport in the world that will accommodate the powerful new compound Wright engines now developing 3500 h.p. each on long-range P2V patrol bombers built for the Navy by Lockheed.

     Its structural strength is such  that it can carry wing-tip fuel tanks, as do military jets on long-range flights, should such a feature become desirable to operators.

     Fifty million dollars in orders already have been received for the new transport from two airline operators and the military services

Los Angeles Times, Tuesday, 17 October 1950, Part II, Page 2, Columns 1–3

The first production Lockheed L-1049 Super Constellation, serial number 4001, registered N6201C, was delivered to Eastern Airlines in March 1952.

Produced from 1951 through 1958, Lockheed built 259 commercial Super Constellations and 320 C-121 military versions.

The first production Lockheed L-1049 Super Constellation, N6201C, s/n 4001. This airplane was delivered to Eastern Airlines in March 1952. (Lockheed Martin Aeronautics Company)
Eastern Airlines Lockheed L-1049 Super Constellation N6203C. (Eastern Airlines)

© 2023, Bryan R. Swopes

30 June 1956

United Airlines' Douglas DC-7 City of San Francisco, sister ship of Mainliner Vancouver.
United Airlines’ Douglas DC-7 City of San Francisco, N6301C, sister ship of Mainliner Vancouver. (UAL)

30 June 1956: At approximately 10:32 a.m., two airliners, United Airlines’ Douglas DC-7 serial number 44288, Mainliner Vancouver, Civil Aeronautics Administration registration N6324C, and Trans World Airlines’ Lockheed L-1049-54-80 Super Constellation serial number 4016, Star of the Seine, N6902C, were over the Grand Canyon at 21,000 feet (6,400 meters).

Both airliners had departed Los Angeles International Airport shortly after 9:00 a.m. TWA Flight 2 was headed for Kansas City Downtown Airport with 64 passengers and 6 crew members. United Flight 718 was enroute to Chicago Midway Airport with 53 passengers and 5 crew members.

The airplanes were over the United States desert southwest, which, at that time, was outside of radar-controlled airspace. They were flying around towering cumulus clouds to comply with regulations that they “remain clear of clouds.”

The airplanes collided at about a 25° angle. The accident report describes the impact:

First contact involved the center fin leading edge of the Constellation and the left aileron tip of the DC-7. The lower surface of the DC-7 left wing struck the upper aft fuselage of the L-1049 with disintegrating force. The collision ripped open the fuselage of the Constellation from just forward of its tail to near the main cabin door. The empennage of the L-1049 separated almost immediately. The plane pitched down and fell to the ground. Most of the left outer wing of the DC-7 had separated and aileron control was restricted. . . .

This illustration depicts the collision. (Milford Joseph Hunter/LIFE Magazine)

The Constellation struck the ground near Temple Butte at an estimated 475 miles per hour (765 kilometers per hour). The DC-7’s left wing was so badly damaged that it went into an uncontrolled left spin and crashed at Chuar Butte. All 128 persons on the two airliners were killed.

This, as well as other accidents, resulted in significant changes in the United States air traffic control system.

A Trans World Airlines Lockheed L-1049 Super Constellation, sister ship of Star of the Seine, photographed over the Grand Canyon. (TWA)

© 2018, Bryan R. Swopes