Abstract: Based on the collection of data on more than 20,000 airplane models created in the world in the XX century, and more than 40,000 records on their manufacturing, world airplane production dynamics was reconstructed year by year in pieces and tons.
An analysis year by year by aircraft purpose and by leading countries is prepared.
The output was calculated not only in pieces, but also by the total mass of structures. The second approach corresponds more precisely to the power of the aviation industry, allowing to differentiate labor and material costs in the production of light and heavy airplanes.
These graphs are constructed and published for the first time.
The role of leading countries in world production is revealed.
It is shown that the decline in production after the First World War more pronounced not in Russia, but in the UK.
It is shown that the USSR firmly held the second place in aircraft production in the world from the mid-1930s to 1990, and in the mid-1930s briefly came out on top in the world.
The influence of the repressions of the 1930s on the aviation industry of the USSR, expressed in a noticeable decrease in the rate of new aircraft models development, is shown.
It was revealed that in the second half of the XX century, the share of combat airplane in production was constantly decreasing, and by 2000 over 80% of the world's airplane industry capacity was occupied by the production of commercial aircraft.

Abstract: The work is devoted to the analysis of a specific sub-branch of airplane construction and, at the same time, to the search of general laws of technology development.
For the first time, a global picture of the development of designs of four-seat airplanes in the XX century is given, priority designs are identified.
It is shown that the development of four-seat airplanes goes through two stages: the search (until the end of the 1940s), when popular airplane schemes periodically replaced each other, the airplane characteristics varied greatly, and the second stage of mature technology.
In the second half of the XX century, both the qualitative and quantitative characteristics of four-seat airplanes remain almost constant and attempts to improve them did not lead to an increase in demand.
The change of technology generations was replaced by coexistence, when each type of construction worked out during the previous period found its market niche. The division of phases, the transition from generation’s change to their coexistence, is clearly visible when analyzing both qualitative and quantitative data of airplanes.
A paradoxical reaction of aircraft manufacturers to the decline in sales was found, expressed in increased design activity and an attempt to offer products with better technical characteristics. The inefficiency of such a reaction was shown.
It is revealed that, contrary to widespread opinion, the change of technological solutions in production is faster than in development. As a result, most of the market is captured not by pioneers and not by retrogrades, but by followers – those who use modern, but already tested technologies in their products.
At the same time, attempts to create and offer aircraft to consumers in a methodology that is no longer in demand have persisted unsuccessfully for decades.

Abstract: The subject of the article is the worldwide production and development of four-seat general-purpose airplanes in the XX century. This is the most important segment of general aviation: more four-seat aircraft have been built than three- and 5-10-seat aircraft combined. One of the article's goals is to determine whether the requirements for products designed to transport four people by air are really changing.
The methodology of the work is collecting information about all aircraft models built. Data about 871 models and more than 2500 records of their production are collected.
  For the first time, production pace and the number of new models of four-seated airplanes have been presented, country-by-country.
Priority constructions are described. The dominant role of the USA and the stable duopoly of Cessna and Piper firms are revealed.
It is shown that the demand for aircraft varies greatly in accordance with the socio-political situation in the world.
The role of the USSR as one of the leading manufacturers of four-seated airplanes is revealed.
It is shown that designers systematically respond to the decline in demand by increasing the intensity of design work, which, however, does not lead to the desired result - an increase in sales. Therefore, such behavior should be recognized as ineffective.

Abstract: The article carries out cluster analysis of serial piston-engine fighters. 672 modifications built in 26 countries from 1913 to 1951 are taken into account. Maximum speed, wing load, power load and weight ratio are chosen as coordinates. Clustering reveals pioneering design: the earliest models in each cluster. One can also measure the dynamics of ideas lifetime that is the period when similar aircrafts (those within one cluster) were manufactured following the same methodology. The frequency new clusters emerged demonstrates the speed of technological progress. The author has found the turning points of development. These are 1930 and 1935. Until 1930 flight characteristics were increasing both due to an increase in thrust-to-weight ratio and an increase of wing load. Later the thrust-to-weight ratio remains practically unchanged. In 1935 the first aircraft appeared from three of the 19 clusters at once. Among them are the little-known Yugoslav fighter Ikarus IK-2 and the Soviet I-16 Type 5. The change of leading countries and the lifetime of ideas have been studied as well. The interval between the manufacture of the first and the last model, related to the cluster, corresponds to the time period when designers followed the same approach when designing an aircraft. Between wars, this interval exceeded 10 years whereas during rapid development periods it was 5-6 years shorter.

Abstract: The article carries out cluster analysis of piston-engine fighters designed between 1920 and 1944 and takes into account more than 500 modifications of aircrafts that were serially manufactured in 18 countries. The author divides the period understudy into five-year segments and studies designs as far as such parameters as maximum speed, wing load and power load are concerned. Correlations of these variables are considered as well and special attention is paid to the correct distance determination. The article demonstrates dynamics of the main fighter characteristics between the world wars. It was found out that the main factor in the growth of fighter speed in 1920-1944 was the wing load related to modernization of profiles, quality and mechanization of the wing rather than growth of engine power of aircrafts. One can see repeating models of development in each period. These are a “power” approach that used new technologies “straightforwardly”, for instance, by totally increasing power loading, and a complex approach that provided for much better results. The author has revealed the leadership of the British aerodynamic school in 1920-1940 and has numerically demonstrated the change in the focus of the US design school from a "powerful engine - light aircraft" method to a "perfect aerodynamics - long flight range" method. He has shown the place of the Soviet design school as well. It has been found out that the last (during this period) sharp increase of wing load was not performed in the USSR and Japan. This led to rather low speed of fighters in these countries during the Second World War. The author discusses the reasons for this as well.

Abstract: The article proposes to estimate the effectiveness of R&D in aircraft industry by new modifications of aircrafts emerging each year. This method is compared with other ones such as those by financial costs, labor costs and bibliometric methods. The advantages and disadvantages of this method are described. The author suggests a technique to check the completeness of raw data based on the use of an independent statistical sampling from the same general set. The author is the first to describe the dynamics of new aircraft modifications creation in the 20th century and compares this graph with that of aircraft manufacture constructed earlier by him. The research method is the statistical analysis of data on the R&D and aircraft manufacture collected by the author within a relational database. It was found that the correlation of R&D and production graphs was disrupted as early as 1910 and completely disappeared after 1930, that the huge increase in aircraft manufacture during the Second World War did not lead to an increase of new modifications and that the R&D graph is more rigid than the manufacture one responding weakly both to economic growth and recession.

Abstract: The article studies the increase of aircraft speed during 1913-1918 in the main countries participating in the First World War: Great Britain, Germany, Italy, Russia, the USA and France. It is the first time when the average speed of aircraft has been calculated. This involved the collection of data on the production of aircrafts by types and years. A separate comparison was made for combat planes and fighters - a class for which speed is of particular importance.
The author has specified data on the amount of planes manufactured within the period understudy as well. He has collected data on airplane production in 1913-1918 and their performance within a database of 2450 records. It is shown that in 1913 the average plane speeds in six countries mentioned above were similar, but by the end of the war the allies (Great Britain, France and Italy) took the lead while Germany and especially Russia lagged behind. In Germany the lag occurred in 1917-1918 and in Russia mainly in the first two years of the war rather than during those revolutionary years. The author concludes that this lag is caused by the increasing share of locally manufactured planes in Russian aircraft industry that reached 50% in 1917-1918.

Abstract: The author has created a database containing information about airplanes produced in the 20th century. There are over 7000 records about airplane manufacture during 1931-1945 in six leading countries. It is the first time when data about airplane manufacture in the USA, the USSR, the British Empire, France, Germany and Japan during this period are presented. They are divided into three five-year periods as far as the purpose of airplanes is concerned. These are 1931-1935, 1936-1940 and 1941-1945. The author has analyzed the difference in the structure and the speed of airplane manufacture and assumed the reason for these differences related to military policy and political goals of the state as well. The result is that the structures of airplane manufacture in the 1930s were similar in the countries that later became allies and differed from the countries that later became Axis members. This is true as far as the ratio of fighters to attack aircrafts and bomber aircrafts is concerned.