Of course, in addition to the Weilong fighter, there is another aircraft that is popular all over the world, and it is the M40 large transport aircraft. This time, not only the armies of various countries have purchased it, but also the world's major airlines. They all value the M40's good economy, as well as its larger passenger capacity and long range.

The M40 large transport aircraft is available in both military and civilian versions. The military type, in addition to transport, can perform bombing missions, as well as gunboat aircraft. There are also two types of civil type: freight type and passenger type, of course, this design is to take into account different needs. For example, there is no need to design a fully sealed pressurized cabin for the cargo cabin, and the cargo compartment does not need to be pressurized, so that the cost of the cargo type will be lower.

Compared to any other transport aircraft in World War II, the M40 large transport aircraft was much more advanced than them. The first is that it is powered by turboprop engines, which are much faster, cruising at 450 km/h and having a maximum speed of 600 km/h, which is faster than all current propeller fighters, not to mention bombers and transport aircraft. It has a maximum range of 2,500 kilometers and an extended-range range of 3,000 kilometers. The maximum carrying capacity is 6 tons.

In contrast, the most famous C47 transport aircraft during World War II, although it appeared many years later, is far inferior to the M40 in performance, because the M40 transport aircraft is designed on the basis of the Y-7 aircraft, and its performance is much higher than that of the Y-7.

In another time and space, the DC series of transport aircraft that Douglas began to develop in the 1930s during World War II was a great success. The DC series transport aircraft is widely used in many countries as civilian and military transport aircraft. There are no less than 28 major military models of DC-1, DC-2, and DC-3 transport planes used in the United States, and the models used in foreign imitations and special models such as gunboats and electronic surveillance planes are not counted. By all accounts, the DC-3/C-47 is a world-changing aircraft!

Now, though, it has to give way to the M40 large transport aircraft.

Douglas & Co. founder Donald Brown. W. Douglas Jr. was born on April 6, 1892, in Brooklyn, New York. After the war ended in 1918, Douglas returned to the Martin Aircraft Company to develop the Martin MB-2 bomber for the Army Air Corps. It was also the first large aircraft he was involved in developing.

Donald. Douglas was not satisfied with this, he dreamed of starting his own company and producing aircraft of his own design. By the mid-1920s, the Douglas aircraft had gained fame in both the military and civilian spheres. Militarily, Douglass created the memorable Douglas World Cruiser for the Army Air Corps, which made the first round-the-world flight in aviation history in 1924. Civil aviation field. The Douglas M-1 became the standard of use at the time, and the United States Postal Service purchased no less than 40 M-2/M-3/M-4 for air mail services.

Douglas Aircraft Company seized the opportunity to launch the DC series of transport aircraft, which not only met the requirements of the airlines at that time, but also became the world's standard civil aircraft in the 1930s~1940s.

On August 2, 1932, the TWA submitted the design specifications to the aviation industry, and the specifications were quite detailed: an all-metal monoplane design, three supercharged engines, each with a power of not less than 500 horsepower. Tandem cockpit. A minimum of 12 passengers can be carried. It also stipulates that the range is not less than 1738 km, the maximum speed is not less than 298 km / h, the cruising speed is not less than 235 km / h, the climb rate is 366 m / min, and the practical ceiling is not less than 3048 m. These requirements were not demanding at the state of the art at the time, but they differed with the addition of a clause to the TWA that "in the event of the loss of an engine and full load, take-off at any of the airports of the TWA must be satisfactorily well controlled". All major aircraft manufacturers except Boeing: General Aviation, Martin, United, Curtis and Douglas received design specifications.

On June 23, 1933, the DC-1 rolled off the assembly line from the assembly plant in Santa Monica, California. She was larger than other airliners at the time, including the Boeing 247. The shape is more sleek. The DC-1 cabin has 5 rows of seats with an aisle in between. It can accommodate up to 10 passengers and is equipped with innovations such as low-fare seats, lavatories for the first time on passenger aircraft, soundproofing, cabin heating, and more. The DC-1 uses Wright Cyclone SGR-1820-F air-cooled star engines, each with 690 horsepower, to drive Hamilton Standards' 3-blade variable pitch propellers, which meet the TWA single-pitch flight requirements. DC-1 has a total length of 18.29 meters. The wingspan is 25.91 meters, the overall height is 4.88 meters, the maximum take-off weight is 7938 kg, the maximum speed is 338 km / h, and the cruising speed is 306 km / h. All exceed the requirements of TWA, and the range is more than 1622 kilometers, and the practical ceiling has reached an astonishing 7010 meters!

The Douglas DC-3 was a product of fierce competition in the aviation industry in the 1930s. The TWA already had the DC-2, the world's best passenger aircraft at the time, which put American Airlines and United Airlines at a competitive disadvantage, but they didn't want to use the same aircraft as the TWA. American Airlines wanted to get an aircraft that offered sleeper service, and the DC-2 did not fully meet their requirements, and they wanted the new aircraft to carry far more passengers than the DC-2, and to be easily converted to a sleeper layout, and to have a significantly better range and stability than the DC-2.

Based on the basic design of DST, several passenger aircraft models have been developed, each with a different seat arrangement or engine model. The DST can accommodate 28 passengers during daytime flights, and 14 passengers can be seated in sleepers during night flights. The DST-A was replaced with a Wright SB-G (R-1830) engine rated at 1,000 horsepower. There is also a model that flies purely during the day, with non-adjustable seats and 28 passengers, which is known as the DC-3. The DC-3 engine was a Wright SGR-1820 Cyclone rated at 1,000 horsepower. The DC-3A was replaced with a Pratt & Whitney SIC-S twin wasp engine. The last model is the Wright Powered DC-3B, where half of the cabin seats are adjustable into sleepers.

The interior of the C-47 was stripped of all the trim, the comfortable civil aviation seats were replaced by 28 folding canvas seats fixed to the bulkheads, the soldiers sat facing each other, and the canvas seats were replaced by metal seats later. When carrying out freight, in order to withstand the weight of the cargo, the cabin floor was strengthened and several fixing cables were set up to secure the cargo. The most peculiar thing is the installation of belly hooks, which can be used for external transportation of some specific goods bundled into rolls. The C-47-DL can also perform the task of transporting the wounded and can accommodate 14 stretchers. With a load capacity of more than 2722 kg, the C-47-DL can transport an entire Jipp trailer, or a 37-mm anti-tank gun.

The C-47 has a maximum speed of 360 km / h, a cruising speed of 260 km / h, a range of 2600 km and a carrying capacity of 2700 kg. The maximum take-off weight is 14000 kg. These data seem to show that, with the exception of the M40 transport aircraft, it is still good. But compared to the M40 transport aircraft is much worse.

Therefore, as soon as the M40 transport aircraft was launched, a large number of orders were obtained, and the world's major airlines wanted to use the M40 transport aircraft as the main aircraft, and they realized that this transport aircraft with new power would have better prospects. (To be continued.) )