Find a Security Clearance Job!

Military


Lockheed L-49 Constellation
L-049 / L-149 / L-649 / L-749

The air transport revolution swung into full power with the building of advanced new airplanes in the latter 1930s. Carriers expressed much interest in four-engine airliners that could carry more passengers at higher speeds, while carrying extra gasoline for longer range. Two aviation leaders competed for advantage in this field: Donald Douglas, whose firm of Douglas Aircraft was building the DC-3, and Howard Hughes. Hughes' father had made a vast fortune in oil. Howard Hughes started his career in Hollywood, but turned to aviation, buying control of TWA. Working with Lockheed Aircraft, he crafted the Constellation airliner.

In 1939, Lockheed began work on a 40-pasenger airliner, the L-049 Constellation, based on an order from TWA. The design of the Lockheed Constellation airliner was resurrected from that of an un-built B-29 competitor. The Lockheed XB-30 was designed in response to the US Army's request for a very heavy bomber capable of speeds of 400 mph and able to deliver a 2,000-pound bomb load more than 2,650 miles (5,300 mile maximum range). Lockheed proposed its model 51-81-01 with a wing span of 123 feet and a length of 104 feet, 8 inches. Four Wright R-3350-13 radial engines of 2,200 hp each were to have powered the aircraft, giving it an estimated top speed of 382 mph. The XB-30 would have carried a crew of 12. The Lockheed design never progressed past the design stage, and only a scale model of the basic design was built.

The L-049 was designed by former Kelly Johnson. Some wind tunnel work for this plane was done at the University of Michigan. Typical of Lockheed in those days, the design was brilliant. The triple-tailed plane incorporated a pressurized cabin, tricycle landing gear, and ultra-modern cabin features. The main wing of the Constellation was scaled up from the wing of the P-38 Lightening, another Kelly Johnson Lockheed creation. To fully use the power of the new engines, very large propellers were attached. In order to clear the ground, the whole plane had to sit up quite high in the air. A single tail would have been too tall to fit into existing hangars. Therefore the triple tail was used. Also, from the Electra Series [Amelia Earhart's plane] through the P-38 fighter-bomber, Lockheed and Kelly Johnson favored multiple tails. It flew as fast as the fighter aircraft of the day, and could cross the nation nonstop. Donald Douglas had to match it, and did so with his own four-engine aircraft, the DC-6 and DC-7.

The prototype Constellation, known by its USAAF designation of C-69, first flew on January 9, 1943. The first flight of the Lockheed Constellation, lasting 58 minutes, was made on 09 January 1943 from Lockheed Air Terminal, Burbank, California. The aircraft, Lockheed Model 49-46-10, serial number 049-1961, registered NX25600, was flown by Eddie Allen. Later in the day, the aircraft is flown to Muroc Flight Test Base (now Edwards AFB), Muroc, California, for additional tests. After numerous tests, the aircraft was delivered to the USAAF (Lockheed says 28 July 1943; the USAAF says 29 July 1943) as C-69-LO, USAAF serial number 43-10309, and was immediately loaned back to Lockheed for further tests and development. This prototype was redesignated XC-69E in January 1946 when it was re-engined. The aircraft was sold to Howard Hughes in mid-1946 for $20,000; later sold to Lockheed in May 1950 for $100,000 with 404 hours on the airframe. After years of being used for Constellation development work, the aircraft was sold to California Airmotive in December 1958 for spare parts; the nose section up to the leading edge of the wings was used to repair another Connie; the remainder of the aircraft was eventually scrapped.

Although both TWA and Pan American had placed orders for the aircraft, the small number then produced was quickly pressed into military as the C-69. The Air Force took over the first batch of Constellations for service as C-69 transports. It was the largest and fastest cargo transport to serve in the war. The plane would form the basis for future civil transports.

The constellations are totally imaginary things that poets, farmers and astronomers have made up over the past 6,000 years (and probably even more!). The real purpose for the constellations is to help us tell which stars are which, nothing more. On a really dark night, you can see about 1000 to 1500 stars. Trying to tell which is which is hard. The constellations help by breaking up the sky into more managable bits.

The end of World War II brought a swift collapse of the aviation industry, as the nation became awash in used aircraft. For airlines, the DC-3 remained popular for short air routes, but coast-to-coast routes along with connections that crossed the Atlantic were gaining in popularity. For these routes only new four-engine aircraft would do. Two families of large, long-range, propeller-driven transports dominated U.S. airlines, as well as many foreign airlines, until the jet transport began to appear in significant numbers toward the end of the 1950's.

These families of aircraft, which served on both long-range domestic and international routes, were the Douglas DC-6 (along with a later and faster version, the DC-7) series and the Lockheed Constellation series. Both were derived from aircraft developed during World War II; they had four supercharged engines and pressurized cabins, and both series underwent large increases in size, power, and weight during their development history. The Constellations and the DC-6s were not without their problems, however. The Constellation was grounded for over two months in 1946, and the DC-6 for over four months in 1947-48 - both as a result of mechanical problems identified in accident investigations.

With only 22 C-69s delivered before the end of hostilities, the military cancelled the remainder of the order. Aircraft already in production were thus finished as civilian airliners, with TWA receiving the first on 1 October 1945. The first transatlantic proving flight departed Washington, DC on 03 December 1945, arriving in Paris on 4 December via Gander and Shannon. In March 1946 TWA, United, and American Airlines began transcontinental service with the Constellation (TWA) and DC-4 (United and American). The characteristic long slender fuselage and the triple tailfin of the Constellation could soon be seen at all major airports of the world. The long range and the pressurized cabin made the Constellation superior to most of her rivals.

In the first ten months of airline service the Constellation suffered several accidents which prompted the suspension of the Constellation's airworthiness certificate until Lockheed could modify the design to remedy the problems. This episode was dramatized in the motion picture The Aviator (2004), in the scene where Howard Hughes (Leonardo DiCaprio) surveys numerous grounded TWA Constellations. On 18 June 1946 an engine of a Pan American aircraft caught fire and fell off, though the flight crew was able to effect an emergency landing with no loss of life. However, on 11 July 1946 a Transcontinental and Western Air aircraft fell victim to an inflight fire, crashing in a field and taking the lives of five of the six on board.

The L-649 and L-749 were the first true commercial Constellations and received their type certificate in March 1947. Essentially an iterative development of the L-049, the type certificate was an "add-on" to the L049 certificate. The model 649 was essentially a "beefed-up" 49, with strengthening in the internal wing structure, landing gear and many other improvements. The 47-gallon integral wing oil tanks were replaced by 56-gallon oil tanks, which were installed in the engine nacelles. At 94,000 lbs (42,638 kg), the 649 represented a 7,500 lb (3,515 kg) increase in maximum takeoff weight and an 1,850 lb (839 kg) increase in payload over the model 49.

The Model L-649 was first Constellation built for civilian air traffic. It flew for the first time (NX101A) on 19 October 1946 and delivery of the first L649 went to Eastern Airlines in May 1947 with Air France receiving the first L749 a month earlier in April 1947. The L-649 was equipped with four R-3350-C18-BD1 engines of 2500 HP each and could carry 48-64, maximum of 81 passengers or 10197kg pay load. Only fourteen L649's and six L649A's were produced for Eastern and Chicago and Southern. This version was replaced 1947 from the L-749.

In 1947 Lockheed introduced a re-engined version, the L-749. The Constellation L-749 was like the L-649 and had the same seating capacity, however an additional 1,130 gallons of fuel tanks in the wing area made non-stop flights possible between New York and Paris (5890km). With the NC86530 Clipper America, Pan Am opened the first airline service on in June 1947 "around the world". The L-749a was variation with strengthened gears, which made an increase of the take off weight around 2268kg on 48534kg. Most aircraft were upgraded to L749A standards sometime during their lifetime. In 1947, with orders for the Constellation at low ebb, Lockheed was considering canceling the project. The US Air Force placed an order in September 1947 for ten C-121A/B's, essentially L-749's, which kept the production line going until more civilian orders were forthcoming.

Beside 12 military L-749A version of Constellation, before it was replaced 1951 from the super Constellation, altogether 221 planes of all versions were built: 22 changes C-69/L-049, 66 L-049 [for a total of eighty-eight of the fifty-four passenger L-49s], 20 L-649/649A and 113 [or 145] of the sixty-four passenger L-749/749A. Altogether 233 Constellations were built.



NEWSLETTER
Join the GlobalSecurity.org mailing list