American bombers and transport aircrafts

After October 1934 when the US government banned single-engined aircraft for use in carrying passengers or in night flying, Lockheed was perfectly placed in the market with their new Model 10 Electra. Besides airline orders, a number of civil operators also purchased the new Model 10. In May 1937, H.T. "Dick" Merrill and J.S. Lambie accomplished a round-trip crossing of the Atlantic Ocean. The feat was declared the first round-trip commercial crossing of that ocean. It won them the Harmon Trophy. On the eastbound trip, they carried newsreels of the crash of the Hindenburg, and on the return trip, they brought photographs of the coronation of King George VI. Probably the most famous use of the Electra was the highly modified Model 10E flown by aviatrix Amelia Earhart. In July 1937, she disappeared in her Electra during an attempted round-the-world flight. Many Electras and their design descendants (the Model 12 Electra Junior and Model 14 Super Electra) were pressed into military service during World War II, for instance the USAAF's C-36. By the end of the war, the Electra design was obsolete, although many smaller airlines and charter services continued to operate Electras into the 1970s.

Lockheed's innovative twin-engine Model 10 Electra, with retractable landing gear and twin fins and rudders, helped establish the company's line of commercial passenger aircraft. The 10-passenger all-metal plane flew for the first time on February 23, 1934. Northwest Airlines was the first airline to use the plane. In the late 1930s, eight U.S. airlines flew the plane as did European, Australian, Canadian, and South American customers. Model 10 Electras were used for long-distance flights, and Major James "Jimmy" Doolittle flew an Electra from Chicago to New Orleans in five hours 55 minutes in 1936—two hours quicker than the previous fastest time. Amelia Earhart disappeared in an Electra on her round-the-world attempt. The Model 10 Electra was followed by the Model 12 Electra Junior executive transport in 1936 that seated six passengers with a two-person crew. Many Model 12s were used by the military, and the National Advisory Committee on Aeronautics (NACA) used a Model 12 to evaluate a wing deicing system that used hot air from the engine exhaust.

The XC-35 was the world's first airplane specifically constructed with a pressure cabin. In the summer of 1936, the Air Corps contracted for a single Lockheed Electra Model 10-A with extensive modifications. The plane, designated XC-35 by the Army, was intended for use as a high-altitude research and pressurized cabin test plane. As a result, the basic Electra fuselage was redesigned with a near circular cross section to better withstand the stresses of pressurization. Next, the large passenger windows were replaced with much smaller slit windows. The interior was split into two sections: the forward pressurized section had room for three crewmen and two passengers. The aft section, behind the pressure bulkhead had room for one additional passenger but could only be used at lower altitudes (below 12,000 feet). Besides the pilot and copilot, the XC-35 carried an engineer who controlled the pressurization and high altitude research equipment. The XC-35 was fitted with a pair of Pratt Whitney XR-1340 radial engines. These 550-hp engines were turbo-supercharged to deliver the necessary high-altitude performance. The plane was designed to fly at altitudes above 30,000 feet.

The Lockheed XC-35 was delivered to Wright Field, Ohio, in May 1937. It first flew later that year, with a cabin that operated at a pressure of 9.5 psi, affording its passengers the ability to fly well above 30,000 feet in shirtsleeve comfort, without the need for oxygen breathing systems. The advent of the XC-35 marked the emergence of the practical pressurized cabin for high-altitude commercial and military aircraft, a milestone event in aerospace history suitably recognized by the award of the Collier Trophy to the XC-35 team in 1938. In 1937, the Air Corps bought three Lockheed Electra Model 10-A twin engine aircraft. These planes were designated Y1C-36 and were essentially identical to the civilian version. The three planes were initially used as senior staff transports throughout the mid and late 1930s. One Y1C-36 crashed in 1938, but the remaining two aircraft were used for regular transport and utility missions during the 1940s into the World War II era. In 1938, the Y1C-36s were re-designated C-36 and later UC-36 (Utility Cargo) in 1943. The UC-36s were eventually sold to the Brazilian Air Force and served into the early 1950s.

Lockheed's innovative twin-engine Model 10 Electra, with retractable landing gear and twin fins and rudders, helped establish the company's line of commercial passenger aircraft. The 10-passenger all-metal plane flew for the first time on February 23, 1934. Northwest Airlines was the first airline to use the plane. In the late 1930s, eight U.S. airlines flew the plane as did European, Australian, Canadian, and South American customers. Model 10 Electras were used for long-distance flights, and Major James "Jimmy" Doolittle flew an Electra from Chicago to New Orleans in five hours 55 minutes in 1936—two hours quicker than the previous fastest time. Amelia Earhart disappeared in an Electra on her round-the-world attempt. The Model 10 Electra was followed by the Model 12 Electra Junior executive transport in 1936 that seated six passengers with a two-person crew. Many Model 12s were used by the military, and the National Advisory Committee on Aeronautics (NACA) used a Model 12 to evaluate a wing deicing system that used hot air from the engine exhaust.

The XC-35 was the world's first airplane specifically constructed with a pressure cabin. In the summer of 1936, the Air Corps contracted for a single Lockheed Electra Model 10-A with extensive modifications. The plane, designated XC-35 by the Army, was intended for use as a high-altitude research and pressurized cabin test plane. As a result, the basic Electra fuselage was redesigned with a near circular cross section to better withstand the stresses of pressurization. Next, the large passenger windows were replaced with much smaller slit windows. The interior was split into two sections: the forward pressurized section had room for three crewmen and two passengers. The aft section, behind the pressure bulkhead had room for one additional passenger but could only be used at lower altitudes (below 12,000 feet). Besides the pilot and copilot, the XC-35 carried an engineer who controlled the pressurization and high altitude research equipment. The XC-35 was fitted with a pair of Pratt Whitney XR-1340 radial engines. These 550-hp engines were turbo-supercharged to deliver the necessary high-altitude performance. The plane was designed to fly at altitudes above 30,000 feet.

The Lockheed XC-35 was delivered to Wright Field, Ohio, in May 1937. It first flew later that year, with a cabin that operated at a pressure of 9.5 psi, affording its passengers the ability to fly well above 30,000 feet in shirtsleeve comfort, without the need for oxygen breathing systems. The advent of the XC-35 marked the emergence of the practical pressurized cabin for high-altitude commercial and military aircraft, a milestone event in aerospace history suitably recognized by the award of the Collier Trophy to the XC-35 team in 1938. In 1937, the Air Corps bought three Lockheed Electra Model 10-A twin engine aircraft. These planes were designated Y1C-36 and were essentially identical to the civilian version. The three planes were initially used as senior staff transports throughout the mid and late 1930s. One Y1C-36 crashed in 1938, but the remaining two aircraft were used for regular transport and utility missions during the 1940s into the World War II era. In 1938, the Y1C-36s were re-designated C-36 and later UC-36 (Utility Cargo) in 1943. The UC-36s were eventually sold to the Brazilian Air Force and served into the early 1950s.

Lockheed's innovative twin-engine Model 10 Electra, with retractable landing gear and twin fins and rudders, helped establish the company's line of commercial passenger aircraft. The 10-passenger all-metal plane flew for the first time on February 23, 1934. Northwest Airlines was the first airline to use the plane. In the late 1930s, eight U.S. airlines flew the plane as did European, Australian, Canadian, and South American customers. Model 10 Electras were used for long-distance flights, and Major James "Jimmy" Doolittle flew an Electra from Chicago to New Orleans in five hours 55 minutes in 1936—two hours quicker than the previous fastest time. Amelia Earhart disappeared in an Electra on her round-the-world attempt. The Model 10 Electra was followed by the Model 12 Electra Junior executive transport in 1936 that seated six passengers with a two-person crew. Many Model 12s were used by the military, and the National Advisory Committee on Aeronautics (NACA) used a Model 12 to evaluate a wing deicing system that used hot air from the engine exhaust.

The XC-35 was the world's first airplane specifically constructed with a pressure cabin. In the summer of 1936, the Air Corps contracted for a single Lockheed Electra Model 10-A with extensive modifications. The plane, designated XC-35 by the Army, was intended for use as a high-altitude research and pressurized cabin test plane. As a result, the basic Electra fuselage was redesigned with a near circular cross section to better withstand the stresses of pressurization. Next, the large passenger windows were replaced with much smaller slit windows. The interior was split into two sections: the forward pressurized section had room for three crewmen and two passengers. The aft section, behind the pressure bulkhead had room for one additional passenger but could only be used at lower altitudes (below 12,000 feet). Besides the pilot and copilot, the XC-35 carried an engineer who controlled the pressurization and high altitude research equipment. The XC-35 was fitted with a pair of Pratt Whitney XR-1340 radial engines. These 550-hp engines were turbo-supercharged to deliver the necessary high-altitude performance. The plane was designed to fly at altitudes above 30,000 feet.

The Lockheed XC-35 was delivered to Wright Field, Ohio, in May 1937. It first flew later that year, with a cabin that operated at a pressure of 9.5 psi, affording its passengers the ability to fly well above 30,000 feet in shirtsleeve comfort, without the need for oxygen breathing systems. The advent of the XC-35 marked the emergence of the practical pressurized cabin for high-altitude commercial and military aircraft, a milestone event in aerospace history suitably recognized by the award of the Collier Trophy to the XC-35 team in 1938.In 1937, the Air Corps bought three Lockheed Electra Model 10-A twin engine aircraft. These planes were designated Y1C-36 and were essentially identical to the civilian version. The three planes were initially used as senior staff transports throughout the mid and late 1930s. One Y1C-36 crashed in 1938, but the remaining two aircraft were used for regular transport and utility missions during the 1940s into the World War II era. In 1938, the Y1C-36s were re-designated C-36 and later UC-36 (Utility Cargo) in 1943. The UC-36s were eventually sold to the Brazilian Air Force
and served into the early 1950s.

Lockheed's innovative twin-engine Model 10 Electra, with retractable landing gear and twin fins and rudders, helped establish the company's line of commercial passenger aircraft. The 10-passenger all-metal plane flew for the first time on February 23, 1934. Northwest Airlines was the first airline to use the plane. In the late 1930s, eight U.S. airlines flew the plane as did European, Australian, Canadian, and South American customers. Model 10 Electras were used for long-distance flights, and Major James "Jimmy" Doolittle flew an Electra from Chicago to New Orleans in five hours 55 minutes in 1936—two hours quicker than the previous fastest time. Amelia Earhart disappeared in an Electra on her round-the-world attempt. The Model 10 Electra was followed by the Model 12 Electra Junior executive transport in 1936 that seated six passengers with a two-person crew. Many Model 12s were used by the military, and the National Advisory Committee on Aeronautics (NACA) used a Model 12 to evaluate a wing deicing system that used hot air from the engine exhaust.

The XC-35 was the world's first airplane specifically constructed with a pressure cabin. In the summer of 1936, the Air Corps contracted for a single Lockheed Electra Model 10-A with extensive modifications. The plane, designated XC-35 by the Army, was intended for use as a high-altitude research and pressurized cabin test plane. As a result, the basic Electra fuselage was redesigned with a near circular cross section to better withstand the stresses of pressurization. Next, the large passenger windows were replaced with much smaller slit windows. The interior was split into two sections: the forward pressurized section had room for three crewmen and two passengers. The aft section, behind the pressure bulkhead had room for one additional passenger but could only be used at lower altitudes (below 12,000 feet). Besides the pilot and copilot, the XC-35 carried an engineer who controlled the pressurization and high altitude research equipment. The XC-35 was fitted with a pair of Pratt Whitney XR-1340 radial engines. These 550-hp engines were turbo-supercharged to deliver the necessary high-altitude performance. The plane was designed to fly at altitudes above 30,000 feet.

The Lockheed XC-35 was delivered to Wright Field, Ohio, in May 1937. It first flew later that year, with a cabin that operated at a pressure of 9.5 psi, affording its passengers the ability to fly well above 30,000 feet in shirtsleeve comfort, without the need for oxygen breathing systems. The advent of the XC-35 marked the emergence of the practical pressurized cabin for high-altitude commercial and military aircraft, a milestone event in aerospace history suitably recognized by the award of the Collier Trophy to the XC-35 team in 1938.In 1937, the Air Corps bought three Lockheed Electra Model 10-A twin engine aircraft. These planes were designated Y1C-36 and were essentially identical to the civilian version. The three planes were initially used as senior staff transports throughout the mid and late 1930s. One Y1C-36 crashed in 1938, but the remaining two aircraft were used for regular transport and utility missions during the 1940s into the World War II era. In 1938, the Y1C-36s were re-designated C-36 and later UC-36 (Utility Cargo) in 1943. The UC-36s were eventually sold to the Brazilian Air Force
and served into the early 1950s.

I love the Grizzly!

Some of Lockheed's wooden designs, such as the Orion, had been built by Detroit Aircraft Corporation with metal fuselages. However, the Electra was Lockheed's first all-metal and twin-engine design by Hall Hibbard. Most of the structure is 7075 Aluminum alloy with 2024 Aluminum alloy used for skin panels and bulkhead webs subjected to tension loads through pressurization. The name Electra came from a star in the Pleiades. The prototype made its first flight on February 23, 1934 with Marshall Headle at the controls. Wind tunnel work on the Electra was undertaken at the University of Michigan. Much of the work was performed by a student assistant, Clarence Johnson. He suggested two changes be made to the design: changing the single tail to double tails (later a Lockheed trademark), and deleting oversized wing fillets. Both of these suggestions were incorporated into production aircraft. Upon receiving his master's degree, Johnson joined Lockheed as a regular employee, ultimately leading the Skunk Works in developing advanced aircraft such as the SR-71 Blackbird.

After October 1934 when the US government banned single-engined aircraft for use in carrying passengers or in night flying, Lockheed was perfectly placed in the market with their new Model 10 Electra. Besides airline orders, a number of civil operators also purchased the new Model 10. In May 1937, H.T. "Dick" Merrill and J.S. Lambie accomplished a round-trip crossing of the Atlantic Ocean. The feat was declared the first round-trip commercial crossing of that ocean. It won them the Harmon Trophy. On the eastbound trip, they carried newsreels of the crash of the Hindenburg, and on the return trip, they brought photographs of the coronation of King George VI. Probably the most famous use of the Electra was the highly modified Model 10E flown by aviatrix Amelia Earhart. In July 1937, she disappeared in her Electra during an attempted round-the-world flight. Many Electras and their design descendants (the Model 12 Electra Junior and Model 14 Super Electra) were pressed into military service during World War II, for instance the USAAF's C-36. By the end of the war, the Electra design was obsolete, although many smaller airlines and charter services continued to operate Electras into the 1970s.

The Model 18 Twin Beech twin-engine aircraft were designed by Beech as a response to global tension in the late 1930s. After the prototype took flight in 1937, China issued a order amounting to $750,000 to convert these aircraft into light bombers, but only 39 were delivered by the time China entered WW2 in Jul 1937. As the United States geared for war, the Model 18 design were built as US Army AT-7 Navigator, AT-11 Kansan, and C-45 Expeditor aircraft and US Navy SNB Kansan, JRB Kansan, and UC-45 Expeditor Navigator aircraft. They were used as transports or trainers. After the war, the US Air Force kept C-45 aircraft in use until 1963, Navy SNB aircraft until 1972, and US Army C-45 aircraft until 1976. The production of the Model 18 aircraft did not stop until 1970, with the last model exported to Japan Airlines, making the design the longest continuous production of a piston engine aircraft; a total of nearly 8,000 were built during the production life. In addition to the production record, Model 18 also held the most US Federal Aviation Administration-approved Supplemental Type Certificates of any aircraft design (over 200), making it the most modified American aircraft. In the civilian world, they were used for a wide variety of functions, including pesticide spraying, fish seeding, firefighting, ambulance service, and cargo and passenger transportation.

my turn to thank you gekho, for some extremely enjoyable threads. I look forward to seeing them and dread the inevitable runout ...
One question a lot of planes in their first - and often best - photos, wear an 'arrow head' on the fuselage; is that a NACA thing?
thanks again, steven

fnqvmuch said:

One question a lot of planes in their first - and often best - photos, wear an 'arrow head' on the fuselage; is that a NACA thing?

Click to expand...

Which, where, when??? I am afraid you gotta be more precise. Tell me the number of the thread.

And thank you for your words..

gekho said:

number of the thread..

Click to expand...

most recent and obviously Electra 003, obscured Electra 006 ... ive seen it on lots of types but always in the evaluation stage, i think. had thought maybe something like indication of CoG for some kinda photographic data collation.

Honestly, I have no idea; I should take notes when I find the pics, but in this case I am afraid I cannot help you. Probably you are right and it is some kind of prototype or evaluation plane...

In March 1940, the Curtiss-Wright company first flew a new 36-seat commercial airliner design, designated the CW-20. The US Army became interested in the aircraft for its cargo/transport capabilities, and ordered a militarized version, the C-46 Commando, be produced, utilizing two 2,000-hp Pratt Whitney R-2800-43 engines. The Commando entered service with the USAAF in July 1942, becoming the largest and heaviest twin-engine aircraft in the Air Corps. The first major variant to appear was the C-46A, which had a large cargo door in the left rear fuselage, 40 folding seats, a strengthened cargo floor, and higher-altitude capable engines. This last feature was to become important when the C-46 began flying cargo "over the Hump" from India to China. The C-46 was found to have much better load-hauling capabilities than the C-47 at the altitudes involved. The Commando also served in the Pacific theater, where it moved troops and supplies from island to island, contributing to the defeat of Japan. In the European Theater, C-46s served as glider tugs, towing two CG-4 gliders at a time across the Rhine River.

Other versions of the aircraft included the R5C-1 (US Navy/Marine Corps designation); the C-46D (personnel version with an extra door on the right side); C-46E (utility version with C-46A doors and a stepped windscreen); and C-46F (cargo model with doors on both sides and square wingtip ends). Well over 3,000 Commandos were built, and they remained in service through the Korean War. A few even served during the first years of the war in Vietnam. Today, a small number continue to fly in various capacities around the world, mostly as freighters in Central and South America.

The USAAF was enthusiastic about the Commando, and a total of 1,479 C-46s and C-46As were built by Curtiss in plants at Buffalo (1,039 "C-46A-CU" Commandos), Saint Louis (two "C-46A-CS" Commandos), and Louisville, Kentucky (438 "C-46A-CK" Commandos). They were flown by the US Army Air Transport Command, Air Service Command, and Troop Carrier Command. About 40 C-46As were passed on to the US Marine Corps with the designation "R5C-1", and some of these aircraft were later passed on to the US Naval Air Transport Command in turn. Demand for the type was so great that the USAAF placed an order for 500 C-46A Commandos with Higgins Industries, famed for construction of landing craft and torpedo boats, but only two "C-46A-HI" Commandos were actually built by Higgins, being delivered in October 1944.

The Commando initially went into service on the South Atlantic ferry route, and would also participate as a glider tug in the Rhine crossings in March 1945. However, due to its long range, it was primarily used in the Pacific and China-Burma-India (CBI) theaters, becoming the primary cargolifter for ferrying supplies from India to China over "the Hump", the Himalaya Mountains, after the Japanese shut down the Burma Road in 1943. Commandos of Colonel Edward H. Alexander's "India-China Wing" of the USAAF Air Transport Command flew from primitive airstrips in the Indian state of Assam, climbing with overload cargoes to clear ridges from 3.7 to 4.3 kilometers (12,000 to 14,000 feet) high, to land at Chunking and drop off their loads for USAAF General Claire Chennault's 14th Air Force and Nationalist Chinese forces.

The loss rate of the C-46 was high and it had a mixed reputation with aircrews. Partly the problem was the fact that environment was very harsh, operating conditions were difficult, and Japanese fighters were an occasional threat. During one attack, Captain Wally A. Gayda shoved a Browning Automatic Rifle out one of the forward cabin windows and shot down the attacker. However, stories still circulate that the C-46 also suffered from a large number of engineering and manufacturing faults, in particular a leaky hydraulic system. Crews were said to take a barrel of hydraulic fluid along on flights to make sure that the hydraulic systems were topped off before they were used. There was also apparently a fuel leak problem that took a long time to work out, with aircraft being lost in midair explosions at a steady rate until it was. It doesn't appear that the C-46 was an inherently bad aircraft, it was just rushed into service without the level of qualification that it would have been run through in peacetime, and it took a lot of work to get the bugs fixed. The aircraft's detractors called it the "Curtiss Calamity" and the "Leaky Tiki", though it was also more affectionately named "Dumbo", after the flying baby elephant in Walt Disney's 1941 animated movie.

Great pics again, thanks. I think the 'arrow head' mentioned above is the Lockheed badge.

fnqvmuch said:

most recent and obviously Electra 003, obscured Electra 006 ... ive seen it on lots of types but always in the evaluation stage, i think. had thought maybe something like indication of CoG for some kinda photographic data collation.

Click to expand...

I believe it is an emblem/badge for Wright field.

Wright Field being the Army base were most evaluations and testing was done.

oh WRIGHT - while just the shape on the Republic and Martin, it says as much in big white caps on the North American ...
steven

Great pics!

The Douglas DC-3 is an American fixed-wing, propeller-driven aircraft whose speed and range revolutionized air transport in the 1930s and 1940s. Because of its lasting impact on the airline industry and World War II it is generally regarded as one of the most significant transport aircraft ever made. Many DC-3s are still used in all parts of the world. The initial design for the DC-3 was a product of conversations between the president of American Airlines, C.R. Smith, and Donald Douglas in 1935. American inaugurated passenger service on June 26, 1936, with simultaneous flights from Newark, N.J. and Chicago, IL.[4] Early U.S. airlines like American, United, TWA and Eastern ordered over 400 DC-3s. These fleets paved the way for the modern American air travel industry, quickly replacing trains as the favored means of long-distance travel across the United States.

During World War II, many civilian DC-3s were drafted for the war effort and just over 10,000 US military versions of the DC-3 were built, under the designations C-47, C-53, R4D, and Dakota. Peak production was reached in 1944, with 4,853 being delivered. The armed forces of many countries used the DC-3 and its military variants for the transport of troops, cargo, and wounded. Licensed copies of the DC-3 were built in Japan as Showa L2D (487 aircraft) and in the USSR as the Lisunov Li-2 (4937 aircraft). Thousands of surplus C-47s, previously operated by several air forces, were converted for civilian use after the war and became the standard equipment of almost all the world's airlines, remaining in front line service for many years. The ready availability of cheap, easily-maintained ex-military C-47s, both large and fast by the standards of the day, jump-started the worldwide post-war air transport industry. While aviation in pre-war Continental Europe had used the metric system, the overwhelming dominance of C-47s and other US war-surplus types cemented the use of nautical miles, knots and feet in post-war aviation throughout the world.

Douglas had developed an improved version, the Super DC-3, with more engine power, greater cargo capacity, and a different wing but, with all the bargain-priced surplus aircraft available, this did not sell well in the civil aviation market. Only five were delivered, three of them to Capital Airlines. The U.S. Navy had 100 of their early R4Ds converted to Super DC-3 standard during the early 1950s as the R4D-8, later C-117D. The last U.S. Navy C-117 was retired 12 July 1976. Several remained in service with small airlines in North and South America in 2006. A number of aircraft companies attempted to design a "DC-3 replacement" over the next three decades (including the very successful Fokker F27 Friendship) but no single type could match the versatility, rugged reliability, and economy of the DC-3. It remained a significant part of air transport systems well into the 1970s.

December 17, 2010, marks the 75th anniversary of the DC-3's first flight, and there are still small operators with DC-3s in revenue service and as cargo aircraft. The common saying among aviation buffs and pilots is that "the only replacement for a DC-3 is another DC-3." The aircraft's legendary ruggedness is enshrined in the lighthearted description of the DC-3 as "a collection of parts flying in loose formation." Its ability to take off and land on grass or dirt runways makes it popular in developing countries, where runways are not always paved. Some of the uses of the DC-3 have included aerial spraying, freight transport, passenger service, military transport, and sport skydiving shuttling and sightseeing.